<?xml version="1.0" encoding="US-ASCII"?>
<!-- Generated by Broadridge Transform (tm) - http://www.broadridge.com -->
<!-- Created: Tue Jun 23 20:29:02 UTC 2026 -->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:xbrldt="http://xbrl.org/2005/xbrldt">
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_EBPStatementNetAssetAvailableBenefit" roleURI="http://navient.com/role/EBPStatementNetAssetAvailableBenefit"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_EBPStatementChangeNetAssetAvailableBenefit" roleURI="http://navient.com/role/EBPStatementChangeNetAssetAvailableBenefit"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_PlanDescription" roleURI="http://navient.com/role/PlanDescription"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_SummaryofSignificantAccountingPolicies" roleURI="http://navient.com/role/SummaryofSignificantAccountingPolicies"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_FairValueMeasurements" roleURI="http://navient.com/role/FairValueMeasurements"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_PlanTermination" roleURI="http://navient.com/role/PlanTermination"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_RelatedPartyTransactionsandPartyInInterestTransactions" roleURI="http://navient.com/role/RelatedPartyTransactionsandPartyInInterestTransactions"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_IncomeTaxStatus" roleURI="http://navient.com/role/IncomeTaxStatus"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_SubsequentEvents" roleURI="http://navient.com/role/SubsequentEvents"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_ScheduleHLine4iScheduleofAssetsHeldatEndofYear" roleURI="http://navient.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYear"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_AccountingPoliciesByPolicy" roleURI="http://navient.com/role/AccountingPoliciesByPolicy"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_FairValueMeasurementsTables" roleURI="http://navient.com/role/FairValueMeasurementsTables"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_StatementsofNetAssetsAvailableforBenefitsMeasuredatFairValueTable" roleURI="http://navient.com/role/StatementsofNetAssetsAvailableforBenefitsMeasuredatFairValueTable"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_ScheduleHLine4iScheduleofAssetsHeldatEndofYearTable" roleURI="http://navient.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearTable"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_ScheduleHLine4iScheduleofAssetsHeldatEndofYearTable0" roleURI="http://navient.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearTable0"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_PlanDescriptionDetails" roleURI="http://navient.com/role/PlanDescriptionDetails"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_PlanTerminationDetails" roleURI="http://navient.com/role/PlanTerminationDetails"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_RelatedPartyTransactionsandPartyInInterestTransactionsDetails" roleURI="http://navient.com/role/RelatedPartyTransactionsandPartyInInterestTransactionsDetails"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_IncomeTaxStatusDetails" roleURI="http://navient.com/role/IncomeTaxStatusDetails"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#navi_r_ScheduleHLine4iScheduleofAssetsHeldatEndofYearDetails" roleURI="http://navient.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearDetails"/>
  <roleRef xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-roles-2025.xsd#ebp-eedm" roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationListsEbp"/>
  <roleRef xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-roles-2025.xsd#eedm" roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists"/>
  <roleRef xlink:type="simple" xlink:href="navi-20251231.xsd#DocumentAndEntityInformation" roleURI="http://navient.com/role/DocumentAndEntityInformation"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" arcroleURI="http://xbrl.org/int/dim/arcrole/all"/>
  <definitionLink xlink:role="http://navient.com/role/EBPStatementNetAssetAvailableBenefit" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/EBPStatementChangeNetAssetAvailableBenefit" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForOtherIncomeLossOnInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForOtherIncomeLossOnInvestment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForOtherIncomeLossOnInvestment" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestment" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnNoteReceivableFromParticipant" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnNoteReceivableFromParticipant"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnNoteReceivableFromParticipant" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContributionCash" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContributionCash"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContributionCash" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionRollover" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionRollover"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionRollover" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecrease" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecrease"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecrease" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan" order="14" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit" order="15" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/PlanDescription" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/SummaryofSignificantAccountingPolicies" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/FairValueMeasurements" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/PlanTermination" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanPlanTerminationTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanPlanTerminationTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanPlanTerminationTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/RelatedPartyTransactionsandPartyInInterestTransactions" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/IncomeTaxStatus" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/SubsequentEvents" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EbpSubsequentEventLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EbpSubsequentEventLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EbpSubsequentEventTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EbpSubsequentEventTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EbpSubsequentEventLineItems" xlink:to="us-gaap-ebp_EbpSubsequentEventTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EbpSubsequentEventTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EbpSubsequentEventLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYear" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTableTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/AccountingPoliciesByPolicy" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanFairValueMeasurementPolicyTextBlock" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanFairValueMeasurementPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="navi_EmployeeBenefitPlanFairValueMeasurementPolicyTextBlock" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantPolicyTextBlock" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanContributionPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanContributionPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanContributionPolicyTextBlock" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock" order="7" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/FairValueMeasurementsTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTableTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/StatementsofNetAssetsAvailableforBenefitsMeasuredatFairValueTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" xlink:to="us-gaap_InvestmentTypeAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeCategorizationMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeCategorizationMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable" xlink:to="dei_LegalEntityAxis" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel1Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel2Member" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MutualFundMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MutualFundMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap_MutualFundMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockFundMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockFundMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockFundMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanSelfDirectedBrokerageAccountMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanSelfDirectedBrokerageAccountMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap-ebp_EmployeeBenefitPlanSelfDirectedBrokerageAccountMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_InvestmentsInFairValueHierarchyMember" xlink:href="navi-20251231.xsd#navi_InvestmentsInFairValueHierarchyMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="navi_InvestmentsInFairValueHierarchyMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="srt_RangeAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember_0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentIdentifierAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIdentifierAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="us-gaap_InvestmentIdentifierAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="us-gaap_InvestmentTypeAxis" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeCategorizationMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeCategorizationMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="dei_LegalEntityAxis" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanParticipantMember" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanParticipantMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="navi_EmployeeBenefitPlanParticipantMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentIssuerNameExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentIssuerNameExtensibleEnumeration"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentIssuerNameExtensibleEnumeration" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPlanInterestInMasterTrustParticipationStatusExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPlanInterestInMasterTrustParticipationStatusExtensibleEnumeration"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPlanInterestInMasterTrustParticipationStatusExtensibleEnumeration" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPartyInInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPartyInInterest"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPartyInInterest" order="4" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearTable0" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="srt_RangeAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember_0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="us-gaap_InvestmentTypeAxis" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeCategorizationMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeCategorizationMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="dei_LegalEntityAxis" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanParticipantMember" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanParticipantMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="navi_EmployeeBenefitPlanParticipantMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentParticipantLoanAfterDeemedDistribution" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentParticipantLoanAfterDeemedDistribution"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentParticipantLoanAfterDeemedDistribution" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPartyInInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPartyInInterest"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPartyInInterest" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/PlanDescriptionDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:to="srt_RangeAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember_0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:to="dei_LegalEntityAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionAvailable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionAvailable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanDescriptionAvailable" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanDefinedContributionPlanHoursOfServiceRequirement" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanDefinedContributionPlanHoursOfServiceRequirement"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanDefinedContributionPlanHoursOfServiceRequirement" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanNumberOfEmployeesTransferred" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanNumberOfEmployeesTransferred"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanNumberOfEmployeesTransferred" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanEmployerContributionParticipantCompensationMatchedPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerContributionParticipantCompensationMatchedPercentage"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanEmployerContributionParticipantCompensationMatchedPercentage" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanParticipantAgeLimitToParticipateInPlan" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanParticipantAgeLimitToParticipateInPlan"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanParticipantAgeLimitToParticipateInPlan" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanIncreaseInAutomaticDeferralRateEachYear" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanIncreaseInAutomaticDeferralRateEachYear"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanIncreaseInAutomaticDeferralRateEachYear" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EbpRiskAndUncertaintyConcentrationOfInvestmentBenchmarkThresholdPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EbpRiskAndUncertaintyConcentrationOfInvestmentBenchmarkThresholdPercentage"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EbpRiskAndUncertaintyConcentrationOfInvestmentBenchmarkThresholdPercentage" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanServicePeriodOfParticipantsToBeEligibleForMatchingContributionFromEmployer" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanServicePeriodOfParticipantsToBeEligibleForMatchingContributionFromEmployer"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanServicePeriodOfParticipantsToBeEligibleForMatchingContributionFromEmployer" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanEmployerMatchingContributionToFirstFivePercentOfParticipantsCompensation" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanEmployerMatchingContributionToFirstFivePercentOfParticipantsCompensation"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanEmployerMatchingContributionToFirstFivePercentOfParticipantsCompensation" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanMaximumPercentageOfParticipantsEligibleForOneHundredPercentageOfEmployerMatchingContribution" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanMaximumPercentageOfParticipantsEligibleForOneHundredPercentageOfEmployerMatchingContribution"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanMaximumPercentageOfParticipantsEligibleForOneHundredPercentageOfEmployerMatchingContribution" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanVestingPeriodOfServiceRequiredFromParticipantsForMatchingContributionAndRelatedEarningsFromEmployer" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanVestingPeriodOfServiceRequiredFromParticipantsForMatchingContributionAndRelatedEarningsFromEmployer"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanVestingPeriodOfServiceRequiredFromParticipantsForMatchingContributionAndRelatedEarningsFromEmployer" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccountDecreaseForEmployerContribution" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccountDecreaseForEmployerContribution"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccountDecreaseForEmployerContribution" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccount" order="14" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage" order="15" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingAmount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingAmount" order="16" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanMaximumNumberOfLoansOutstanding" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanMaximumNumberOfLoansOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanMaximumNumberOfLoansOutstanding" order="17" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMinimumBorrowingTerm" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMinimumBorrowingTerm"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMinimumBorrowingTerm" order="18" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingTerm" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingTerm"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingTerm" order="19" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanNoteReceivableFromParticipantPrincipalResidenceMaximumBorrowingTerm" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanNoteReceivableFromParticipantPrincipalResidenceMaximumBorrowingTerm"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanNoteReceivableFromParticipantPrincipalResidenceMaximumBorrowingTerm" order="20" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanPartialLoanRepayment" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanPartialLoanRepayment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanPartialLoanRepayment" order="21" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate" order="22" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EmployeeBenefitPlanNormalRetirement" xlink:href="navi-20251231.xsd#navi_EmployeeBenefitPlanNormalRetirement"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EmployeeBenefitPlanNormalRetirement" order="23" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/PlanTerminationDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBPParticipantAccountVestedPercentageUponPlanTermination" xlink:href="navi-20251231.xsd#navi_EBPParticipantAccountVestedPercentageUponPlanTermination"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="navi_EBPParticipantAccountVestedPercentageUponPlanTermination" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/RelatedPartyTransactionsandPartyInInterestTransactionsDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable" xlink:to="us-gaap_InvestmentTypeAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeCategorizationMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeCategorizationMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable" xlink:to="dei_LegalEntityAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockFundMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockFundMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockFundMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForOtherIncomeLossOnInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForOtherIncomeLossOnInvestment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForOtherIncomeLossOnInvestment" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentPlanInterestInMasterTrustFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentPlanInterestInMasterTrustFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentPlanInterestInMasterTrustFairValue" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfSharesPurchased" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfSharesPurchased"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfSharesPurchased" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfSharesSold" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfSharesSold"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfSharesSold" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForDividendIncomeOnInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForDividendIncomeOnInvestment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForDividendIncomeOnInvestment" order="7" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/IncomeTaxStatusDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterObtained" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterObtained"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterObtained" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterDate" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterDate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterDate" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanTaxQualificationStatusExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxQualificationStatusExtensibleEnumeration"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanTaxQualificationStatusExtensibleEnumeration" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EbpPlanName" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EbpPlanName"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EbpPlanName" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityTaxIdentificationNumber" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="dei_EntityTaxIdentificationNumber" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanPlanNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanPlanNumber"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="us-gaap-ebp_EmployeeBenefitPlanPlanNumber" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationListsEbp" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain" xlink:to="us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedMember" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MutualFundMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MutualFundMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap_MutualFundMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentIssuerNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIssuerNameDomain"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdmRetireDMember" xlink:href="navi-20251231.xsd#navi_FidFrdmRetireDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdmRetireDMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanSelfDirectedBrokerageAccountMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanSelfDirectedBrokerageAccountMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap-ebp_EmployeeBenefitPlanSelfDirectedBrokerageAccountMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_BrokeragelinkMember" xlink:href="navi-20251231.xsd#navi_BrokeragelinkMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_BrokeragelinkMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_NavientStockFundMember" xlink:href="navi-20251231.xsd#navi_NavientStockFundMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_NavientStockFundMember" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_Sp500IndexPlClCMember" xlink:href="navi-20251231.xsd#navi_Sp500IndexPlClCMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_Sp500IndexPlClCMember" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_PutnamStableValueMember" xlink:href="navi-20251231.xsd#navi_PutnamStableValueMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_PutnamStableValueMember" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_DodgeCoxIncomeXMember" xlink:href="navi-20251231.xsd#navi_DodgeCoxIncomeXMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_DodgeCoxIncomeXMember" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetirementPlanTaxStatusDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTaxStatusDomain"/>
    <loc xlink:type="locator" xlink:label="us-gaap_QualifiedPlanMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_QualifiedPlanMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RetirementPlanTaxStatusDomain" xlink:to="us-gaap_QualifiedPlanMember" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2045CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2045CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2045CpDMember" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_AsSplSmCapValEMember" xlink:href="navi-20251231.xsd#navi_AsSplSmCapValEMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_AsSplSmCapValEMember" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2025CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2025CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2025CpDMember" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidBalancedKMember" xlink:href="navi-20251231.xsd#navi_FidBalancedKMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidBalancedKMember" order="14" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2070CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2070CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2070CpDMember" order="15" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2065CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2065CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2065CpDMember" order="16" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2055CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2055CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2055CpDMember" order="17" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidOtcPoolAMember" xlink:href="navi-20251231.xsd#navi_FidOtcPoolAMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidOtcPoolAMember" order="18" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_ColOverseasValRMember" xlink:href="navi-20251231.xsd#navi_ColOverseasValRMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_ColOverseasValRMember" order="19" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_VictorySEstbValYMember" xlink:href="navi-20251231.xsd#navi_VictorySEstbValYMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_VictorySEstbValYMember" order="20" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2035CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2035CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2035CpDMember" order="21" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_AfWashMutlInvR6Member" xlink:href="navi-20251231.xsd#navi_AfWashMutlInvR6Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_AfWashMutlInvR6Member" order="22" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2040CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2040CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2040CpDMember" order="23" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidContraPoolClAMember" xlink:href="navi-20251231.xsd#navi_FidContraPoolClAMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidContraPoolClAMember" order="24" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_JhEnterpriseIiiMember" xlink:href="navi-20251231.xsd#navi_JhEnterpriseIiiMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_JhEnterpriseIiiMember" order="25" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_CommonCollectiveTrustMember" xlink:href="navi-20251231.xsd#navi_CommonCollectiveTrustMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="navi_CommonCollectiveTrustMember" order="26" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2020CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2020CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2020CpDMember" order="27" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_LoomisSmCpGrthNMember" xlink:href="navi-20251231.xsd#navi_LoomisSmCpGrthNMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_LoomisSmCpGrthNMember" order="28" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2060CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2060CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2060CpDMember" order="29" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2015CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2015CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2015CpDMember" order="30" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_SpSmallCpIndClCMember" xlink:href="navi-20251231.xsd#navi_SpSmallCpIndClCMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_SpSmallCpIndClCMember" order="31" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_VangVmmrFedMmktMember" xlink:href="navi-20251231.xsd#navi_VangVmmrFedMmktMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_VangVmmrFedMmktMember" order="32" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_SpMidCapIdxClCMember" xlink:href="navi-20251231.xsd#navi_SpMidCapIdxClCMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_SpMidCapIdxClCMember" order="33" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2050CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2050CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2050CpDMember" order="34" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2030CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2030CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2030CpDMember" order="35" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidInflPrBdIdxMember" xlink:href="navi-20251231.xsd#navi_FidInflPrBdIdxMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidInflPrBdIdxMember" order="36" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_SpIntlIndexCMember" xlink:href="navi-20251231.xsd#navi_SpIntlIndexCMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_SpIntlIndexCMember" order="37" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockFundMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockFundMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockFundMember" order="38" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidFrdm2010CpDMember" xlink:href="navi-20251231.xsd#navi_FidFrdm2010CpDMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidFrdm2010CpDMember" order="39" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_FidUsBondIdxMember" xlink:href="navi-20251231.xsd#navi_FidUsBondIdxMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_FidUsBondIdxMember" order="40" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_PgimGlbTotRtnZMember" xlink:href="navi-20251231.xsd#navi_PgimGlbTotRtnZMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InvestmentIssuerNameDomain" xlink:to="navi_PgimGlbTotRtnZMember" order="41" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://navient.com/role/DocumentAndEntityInformation" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="dei_DocumentInformationLineItems" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems"/>
    <loc xlink:type="locator" xlink:label="dei_DocumentInformationTable" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentInformationTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dei_DocumentInformationTable" xlink:to="dei_LegalEntityAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityDomain_0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="navi_EBP001Member" xlink:href="navi-20251231.xsd#navi_EBP001Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="navi_EBP001Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityCentralIndexKey" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityCentralIndexKey" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_DocumentType" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentType" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_DocumentPeriodEndDate" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentPeriodEndDate" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_DocumentFiscalYearFocus" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalYearFocus"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentFiscalYearFocus" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_EntityRegistrantName" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityRegistrantName" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="dei_AmendmentFlag" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
<!-- [WMV7][086IY9DXyEhckIf28V2Bdt5dP4XYG9cDmBnIFIIgDN6xXa9LBcIs9b+XN6T6782uKYQkEGiqXy0eeKa9Ypy+IeJlxBuZYhxgduJs1IqQ1P0XKYij0wwPV2X3Fj/SiS0SvgokH6PPvivCr83ptMX7lNqhQz8su9wXlizrP4kJ0DF3fc4zd/V8URz+B82MkaXx4r2aWlpaL9rAvb5exdvaANu5l8aFEh+0rSCjy27DOmFAhSGag8b26gspuCQmwBW886TgjCCi0bN/DWGz0A9fEWCsyM+r6U/JWF3eF5lxcK9EJh1gZUCOnqdGxVsqXlNiRPdWfqmVIc4dg3csgudvgMam523bFaypeg==] CSR-->
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AmendmentFlag" order="5" xbrldt:closed="true"/>
  </definitionLink>
</linkbase>
