﻿<?xml version="1.0" encoding="utf-8"?>
<linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.xbrl.org/2003/linkbase">
  <roleRef roleURI="https://www.esma.europa.eu/xbrl/role/cor/esef_role-999999" xlink:href="https://www.esma.europa.eu/taxonomy/2024-03-27/esef_cor.xsd#esef_role-999999" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <roleRef roleURI="http://www.sparebank1.no/nb/ostfold-akershus/privat.html/roles/Anchoring" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#Anchoring" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <roleRef roleURI="http://www.sparebank1.no/nb/ostfold-akershus/privat.html/roles/StatementOfChangesInEquity" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#StatementOfChangesInEquity" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <arcroleRef arcroleURI="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" xlink:href="http://www.xbrl.org/lrr/arcrole/esma-arcrole-2018-11-21.xsd#wider-narrower" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <definitionLink xlink:role="https://www.esma.europa.eu/xbrl/role/cor/esef_role-999999" xlink:type="extended" xmlns:xlink="http://www.w3.org/1999/xlink">
    <loc xlink:type="locator" xlink:href="https://www.esma.europa.eu/taxonomy/2024-03-27/esef_cor.xsd#esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:label="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfInterestIncomeExplanatory" xlink:label="ifrs-full_DisclosureOfInterestIncomeExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfFeeAndCommissionIncomeExpenseExplanatory" xlink:label="ifrs-full_DisclosureOfFeeAndCommissionIncomeExpenseExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfFinanceIncomeExplanatory" xlink:label="ifrs-full_DisclosureOfFinanceIncomeExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfEmployeeBenefitsExplanatory" xlink:label="ifrs-full_DisclosureOfEmployeeBenefitsExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfOtherOperatingExpenseExplanatory" xlink:label="ifrs-full_DisclosureOfOtherOperatingExpenseExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfDefinedBenefitPlansExplanatory" xlink:label="ifrs-full_DisclosureOfDefinedBenefitPlansExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfIncomeTaxExplanatory" xlink:label="ifrs-full_DisclosureOfIncomeTaxExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfFinancialInstrumentsExplanatory" xlink:label="ifrs-full_DisclosureOfFinancialInstrumentsExplanatory" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Fairvalueassessmentofthefinancialinstruments" xlink:label="SB1ostfoldakershus_Fairvalueassessmentofthefinancialinstruments" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Fairvalueoffinancialinstrumentsassessedatamortizedcostorcostprice" xlink:label="SB1ostfoldakershus_Fairvalueoffinancialinstrumentsassessedatamortizedcostorcostprice" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfOtherNoncurrentAssetsExplanatory" xlink:label="ifrs-full_DisclosureOfOtherNoncurrentAssetsExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfDerivativeFinancialInstrumentsExplanatory" xlink:label="ifrs-full_DisclosureOfDerivativeFinancialInstrumentsExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfSignificantInvestmentsInAssociatesExplanatory" xlink:label="ifrs-full_DisclosureOfSignificantInvestmentsInAssociatesExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfIntangibleAssetsAndGoodwillExplanatory" xlink:label="ifrs-full_DisclosureOfIntangibleAssetsAndGoodwillExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfPropertyPlantAndEquipmentExplanatory" xlink:label="ifrs-full_DisclosureOfPropertyPlantAndEquipmentExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfPrepaymentsAndOtherAssetsExplanatory" xlink:label="ifrs-full_DisclosureOfPrepaymentsAndOtherAssetsExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfDepositsFromCustomersExplanatory" xlink:label="ifrs-full_DisclosureOfDepositsFromCustomersExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfDebtSecuritiesExplanatory" xlink:label="ifrs-full_DisclosureOfDebtSecuritiesExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfOtherCurrentLiabilitiesExplanatory" xlink:label="ifrs-full_DisclosureOfOtherCurrentLiabilitiesExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfSubordinatedLiabilitiesExplanatory" xlink:label="ifrs-full_DisclosureOfSubordinatedLiabilitiesExplanatory" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Disclosureofhedgeaccounting" xlink:label="SB1ostfoldakershus_Disclosureofhedgeaccounting" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfSignificantInvestmentsInSubsidiariesExplanatory" xlink:label="ifrs-full_DisclosureOfSignificantInvestmentsInSubsidiariesExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DescriptionOfAccountingPolicyForTransactionsWithRelatedPartiesExplanatory" xlink:label="ifrs-full_DescriptionOfAccountingPolicyForTransactionsWithRelatedPartiesExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfShareCapitalReservesAndOtherEquityInterestExplanatory" xlink:label="ifrs-full_DisclosureOfShareCapitalReservesAndOtherEquityInterestExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfNoncurrentAssetsHeldForSaleAndDiscontinuedOperationsExplanatory" xlink:label="ifrs-full_DisclosureOfNoncurrentAssetsHeldForSaleAndDiscontinuedOperationsExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfEventsAfterReportingPeriodExplanatory" xlink:label="ifrs-full_DisclosureOfEventsAfterReportingPeriodExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfGoodwillExplanatory" xlink:label="ifrs-full_DisclosureOfGoodwillExplanatory" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfInterestIncomeExplanatory" order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfFeeAndCommissionIncomeExpenseExplanatory" order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfFinanceIncomeExplanatory" order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfEmployeeBenefitsExplanatory" order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfOtherOperatingExpenseExplanatory" order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfDefinedBenefitPlansExplanatory" order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfIncomeTaxExplanatory" order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfFinancialInstrumentsExplanatory" order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Fairvalueassessmentofthefinancialinstruments" order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Fairvalueoffinancialinstrumentsassessedatamortizedcostorcostprice" order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfOtherNoncurrentAssetsExplanatory" order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfDerivativeFinancialInstrumentsExplanatory" order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfSignificantInvestmentsInAssociatesExplanatory" order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfIntangibleAssetsAndGoodwillExplanatory" order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfPropertyPlantAndEquipmentExplanatory" order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfPrepaymentsAndOtherAssetsExplanatory" order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfDepositsFromCustomersExplanatory" order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfDebtSecuritiesExplanatory" order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfOtherCurrentLiabilitiesExplanatory" order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfSubordinatedLiabilitiesExplanatory" order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Disclosureofhedgeaccounting" order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfSignificantInvestmentsInSubsidiariesExplanatory" order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DescriptionOfAccountingPolicyForTransactionsWithRelatedPartiesExplanatory" order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfShareCapitalReservesAndOtherEquityInterestExplanatory" order="24" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfNoncurrentAssetsHeldForSaleAndDiscontinuedOperationsExplanatory" order="25" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfEventsAfterReportingPeriodExplanatory" order="26" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfGoodwillExplanatory" order="27" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfGeneralInformationAboutFinancialStatementsExplanatory" xlink:label="ifrs-full_DisclosureOfGeneralInformationAboutFinancialStatementsExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_StatementOfIFRSCompliance" xlink:label="ifrs-full_StatementOfIFRSCompliance" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfAccountingJudgementsAndEstimatesExplanatory" xlink:label="ifrs-full_DisclosureOfAccountingJudgementsAndEstimatesExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfChangesInAccountingPoliciesAccountingEstimatesAndErrorsExplanatory" xlink:label="ifrs-full_DisclosureOfChangesInAccountingPoliciesAccountingEstimatesAndErrorsExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfEntitysReportableSegmentsExplanatory" xlink:label="ifrs-full_DisclosureOfEntitysReportableSegmentsExplanatory" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Disclosureofcapitalequirements" xlink:label="SB1ostfoldakershus_Disclosureofcapitalequirements" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfFinancialRiskManagementExplanatory" xlink:label="ifrs-full_DisclosureOfFinancialRiskManagementExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfLoansAndAdvancesToCustomersExplanatory" xlink:label="ifrs-full_DisclosureOfLoansAndAdvancesToCustomersExplanatory" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Transfer_of_loans" xlink:label="SB1ostfoldakershus_Transfer_of_loans" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Age_distribution_of_loans_due_but_not_written_down" xlink:label="SB1ostfoldakershus_Age_distribution_of_loans_due_but_not_written_down" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfImpairmentOfAssetsExplanatory" xlink:label="ifrs-full_DisclosureOfImpairmentOfAssetsExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfCreditRiskExplanatory" xlink:label="ifrs-full_DisclosureOfCreditRiskExplanatory" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Disclosureof_Credit_quality_per_class_of_financial_assets" xlink:label="SB1ostfoldakershus_Disclosureof_Credit_quality_per_class_of_financial_assets" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfMarketRiskExplanatory" xlink:label="ifrs-full_DisclosureOfMarketRiskExplanatory" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Market_risk_linked_to_currency_risk" xlink:label="SB1ostfoldakershus_Market_risk_linked_to_currency_risk" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfLiquidityRiskExplanatory" xlink:label="ifrs-full_DisclosureOfLiquidityRiskExplanatory" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfAdditionalInformationAboutUnderstandingFinancialPositionsAndLiquidityOfEntityExplanatory" xlink:label="ifrs-full_DisclosureOfAdditionalInformationAboutUnderstandingFinancialPositionsAndLiquidityOfEntityExplanatory" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfGeneralInformationAboutFinancialStatementsExplanatory" order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_StatementOfIFRSCompliance" order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfAccountingJudgementsAndEstimatesExplanatory" order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfChangesInAccountingPoliciesAccountingEstimatesAndErrorsExplanatory" order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfEntitysReportableSegmentsExplanatory" order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Disclosureofcapitalequirements" order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfFinancialRiskManagementExplanatory" order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfLoansAndAdvancesToCustomersExplanatory" order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Transfer_of_loans" order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Age_distribution_of_loans_due_but_not_written_down" order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfImpairmentOfAssetsExplanatory" order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfCreditRiskExplanatory" order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Disclosureof_Credit_quality_per_class_of_financial_assets" order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfMarketRiskExplanatory" order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Market_risk_linked_to_currency_risk" order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfLiquidityRiskExplanatory" order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DisclosureOfAdditionalInformationAboutUnderstandingFinancialPositionsAndLiquidityOfEntityExplanatory" order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InterestIncomeOnLoansAndAdvancesToCustomers" xlink:label="ifrs-full_InterestIncomeOnLoansAndAdvancesToCustomers" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteinntekterMaltTilVirkeligVerdi" xlink:label="SB1ostfoldakershus_RenteinntekterMaltTilVirkeligVerdi" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InterestExpense" xlink:label="ifrs-full_InterestExpense" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_NettoRenteinntekter" xlink:label="SB1ostfoldakershus_NettoRenteinntekter" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_FeeAndCommissionIncome" xlink:label="ifrs-full_FeeAndCommissionIncome" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_FeeAndCommissionExpense" xlink:label="ifrs-full_FeeAndCommissionExpense" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherIncome" xlink:label="ifrs-full_OtherIncome" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_NettoProvisjonsinntekterOgAndreInntekter" xlink:label="SB1ostfoldakershus_NettoProvisjonsinntekterOgAndreInntekter" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_RevenueFromDividends" xlink:label="ifrs-full_RevenueFromDividends" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ShareOfProfitLossOfContinuingOperationsOfAssociatesAndJointVenturesAccountedForUsingEquityMethod" xlink:label="ifrs-full_ShareOfProfitLossOfContinuingOperationsOfAssociatesAndJointVenturesAccountedForUsingEquityMethod" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_GainsLossesOnFinancialAssetsAtFairValueThroughProfitOrLossDesignatedAsUponInitialRecognition" xlink:label="ifrs-full_GainsLossesOnFinancialAssetsAtFairValueThroughProfitOrLossDesignatedAsUponInitialRecognition" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_Revenue" xlink:label="ifrs-full_Revenue" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_EmployeeBenefitsExpense" xlink:label="ifrs-full_EmployeeBenefitsExpense" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherExpenseByNature" xlink:label="ifrs-full_OtherExpenseByNature" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_OperatingExpensesBeforeTaxAndImpairment" xlink:label="SB1ostfoldakershus_OperatingExpensesBeforeTaxAndImpairment" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_ProfitLossBeforeTaxAndImpairment" xlink:label="SB1ostfoldakershus_ProfitLossBeforeTaxAndImpairment" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ImpairmentLossImpairmentGainAndReversalOfImpairmentLossDeterminedInAccordanceWithIFRS9" xlink:label="ifrs-full_ImpairmentLossImpairmentGainAndReversalOfImpairmentLossDeterminedInAccordanceWithIFRS9" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ProfitLossBeforeTax" xlink:label="ifrs-full_ProfitLossBeforeTax" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IncomeTaxExpenseContinuingOperations" xlink:label="ifrs-full_IncomeTaxExpenseContinuingOperations" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_BasicEarningsLossPerShare" xlink:label="ifrs-full_BasicEarningsLossPerShare" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans" xlink:label="ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IncomeTaxRelatingToRemeasurementsOfDefinedBenefitPlansOfOtherComprehensiveIncome" xlink:label="ifrs-full_IncomeTaxRelatingToRemeasurementsOfDefinedBenefitPlansOfOtherComprehensiveIncome" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossBeforeTax" xlink:label="ifrs-full_ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossBeforeTax" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherComprehensiveIncomeBeforeTaxFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome" xlink:label="ifrs-full_OtherComprehensiveIncomeBeforeTaxFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLoss" xlink:label="ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLoss" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_PeriodensUtvidedeResultat" xlink:label="SB1ostfoldakershus_PeriodensUtvidedeResultat" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_UtvidetResultatUtvannetUtvidetResultat" xlink:label="SB1ostfoldakershus_UtvidetResultatUtvannetUtvidetResultat" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DilutedEarningsLossPerShare" xlink:label="ifrs-full_DilutedEarningsLossPerShare" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_CashAndBankBalancesAtCentralBanks" xlink:label="ifrs-full_CashAndBankBalancesAtCentralBanks" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_LoansAndAdvancesToBanks" xlink:label="ifrs-full_LoansAndAdvancesToBanks" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_LoansAndAdvancesToCustomers" xlink:label="ifrs-full_LoansAndAdvancesToCustomers" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherDebtInstrumentsHeld" xlink:label="ifrs-full_OtherDebtInstrumentsHeld" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_NoncurrentDerivativeFinancialAssets" xlink:label="ifrs-full_NoncurrentDerivativeFinancialAssets" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_EquityInstrumentsHeld" xlink:label="ifrs-full_EquityInstrumentsHeld" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InvestmentAccountedForUsingEquityMethod" xlink:label="ifrs-full_InvestmentAccountedForUsingEquityMethod" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InvestmentsInSubsidiariesJointVenturesAndAssociates" xlink:label="ifrs-full_InvestmentsInSubsidiariesJointVenturesAndAssociates" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_Goodwill" xlink:label="ifrs-full_Goodwill" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_PropertyPlantAndEquipment" xlink:label="ifrs-full_PropertyPlantAndEquipment" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherNonfinancialAssets" xlink:label="ifrs-full_OtherNonfinancialAssets" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_Assets" xlink:label="ifrs-full_Assets" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DepositsFromBanks" xlink:label="ifrs-full_DepositsFromBanks" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DepositsFromCustomers" xlink:label="ifrs-full_DepositsFromCustomers" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_CurrentDebtInstrumentsIssued" xlink:label="ifrs-full_CurrentDebtInstrumentsIssued" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_NoncurrentDerivativeFinancialLiabilities" xlink:label="ifrs-full_NoncurrentDerivativeFinancialLiabilities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherLiabilities" xlink:label="ifrs-full_OtherLiabilities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_SubordinatedLiabilities" xlink:label="ifrs-full_SubordinatedLiabilities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_Liabilities" xlink:label="ifrs-full_Liabilities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IssuedCapital" xlink:label="ifrs-full_IssuedCapital" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_SharePremium" xlink:label="ifrs-full_SharePremium" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_CapitalReserve" xlink:label="ifrs-full_CapitalReserve" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_AllocatedToDividendsGifts" xlink:label="SB1ostfoldakershus_AllocatedToDividendsGifts" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_HybridCapital" xlink:label="SB1ostfoldakershus_HybridCapital" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_AdditionalPaidinCapital" xlink:label="ifrs-full_AdditionalPaidinCapital" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Gavefond" xlink:label="SB1ostfoldakershus_Gavefond" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome" xlink:label="ifrs-full_ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherReserves" xlink:label="ifrs-full_OtherReserves" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_EquityAndLiabilities" xlink:label="ifrs-full_EquityAndLiabilities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_AdjustmentsForDecreaseIncreaseInTradeAndOtherReceivables" xlink:label="ifrs-full_AdjustmentsForDecreaseIncreaseInTradeAndOtherReceivables" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InterestReceivedClassifiedAsOperatingActivities" xlink:label="ifrs-full_InterestReceivedClassifiedAsOperatingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_AdjustmentsForIncreaseDecreaseInDepositsFromCustomers" xlink:label="ifrs-full_AdjustmentsForIncreaseDecreaseInDepositsFromCustomers" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InterestPaidClassifiedAsOperatingActivities" xlink:label="ifrs-full_InterestPaidClassifiedAsOperatingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_AdjustmentsForIncreaseDecreaseInDepositsFromBanks" xlink:label="ifrs-full_AdjustmentsForIncreaseDecreaseInDepositsFromBanks" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteinnbetalingPaLanTilKredittinstitusjoner" xlink:label="SB1ostfoldakershus_RenteinnbetalingPaLanTilKredittinstitusjoner" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_AndreRenteutbetalinger" xlink:label="SB1ostfoldakershus_AndreRenteutbetalinger" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Innbetalingsertifikaterogobligasjoner" xlink:label="SB1ostfoldakershus_Innbetalingsertifikaterogobligasjoner" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Utbetalingsertifikaterogobligasjoner" xlink:label="SB1ostfoldakershus_Utbetalingsertifikaterogobligasjoner" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteinnbetalingerPaSertifikatOgObligasjoner" xlink:label="SB1ostfoldakershus_RenteinnbetalingerPaSertifikatOgObligasjoner" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ReceiptsFromRoyaltiesFeesCommissionsAndOtherRevenue" xlink:label="ifrs-full_ReceiptsFromRoyaltiesFeesCommissionsAndOtherRevenue" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherCashPaymentsFromOperatingActivities" xlink:label="ifrs-full_OtherCashPaymentsFromOperatingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IncomeTaxesPaidRefundClassifiedAsOperatingActivities" xlink:label="ifrs-full_IncomeTaxesPaidRefundClassifiedAsOperatingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_CashFlowsFromUsedInOperatingActivities" xlink:label="ifrs-full_CashFlowsFromUsedInOperatingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" xlink:label="ifrs-full_PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ProceedsFromSalesOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" xlink:label="ifrs-full_ProceedsFromSalesOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherCashPaymentsToAcquireEquityOrDebtInstrumentsOfOtherEntitiesClassifiedAsInvestingActivities" xlink:label="ifrs-full_OtherCashPaymentsToAcquireEquityOrDebtInstrumentsOfOtherEntitiesClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_InnbetalingFraSalgAvLangsiktigeInvesteringerIVerdipapirer" xlink:label="SB1ostfoldakershus_InnbetalingFraSalgAvLangsiktigeInvesteringerIVerdipapirer" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DividendsReceivedClassifiedAsInvestingActivities" xlink:label="ifrs-full_DividendsReceivedClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_CashFlowsFromUsedInInvestingActivities" xlink:label="ifrs-full_CashFlowsFromUsedInInvestingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ProceedsFromBorrowingsClassifiedAsFinancingActivities" xlink:label="ifrs-full_ProceedsFromBorrowingsClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_RepaymentsOfBorrowingsClassifiedAsFinancingActivities" xlink:label="ifrs-full_RepaymentsOfBorrowingsClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InterestPaidClassifiedAsFinancingActivities" xlink:label="ifrs-full_InterestPaidClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_NettoInnUtbetalingVedInnskuddFraKredittinstitusjoner" xlink:label="SB1ostfoldakershus_NettoInnUtbetalingVedInnskuddFraKredittinstitusjoner" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteutbetalingPaInnskuddFraKredittinstitusjonar" xlink:label="SB1ostfoldakershus_RenteutbetalingPaInnskuddFraKredittinstitusjonar" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ProceedsFromIssueOfSubordinatedLiabilities" xlink:label="ifrs-full_ProceedsFromIssueOfSubordinatedLiabilities" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLanOgFondsobligasjon" xlink:label="SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLanOgFondsobligasjon" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ProceedsFromIssueOfRegulatoryCapitalEquity" xlink:label="ifrs-full_ProceedsFromIssueOfRegulatoryCapitalEquity" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLan" xlink:label="SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLan" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherInflowsOutflowsOfCashClassifiedAsInvestingActivities" xlink:label="ifrs-full_OtherInflowsOutflowsOfCashClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_PaymentsToAcquireOrRedeemEntitysShares" xlink:label="ifrs-full_PaymentsToAcquireOrRedeemEntitysShares" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ProceedsFromSaleOrIssueOfTreasuryShares" xlink:label="ifrs-full_ProceedsFromSaleOrIssueOfTreasuryShares" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DividendsPaidClassifiedAsFinancingActivities" xlink:label="ifrs-full_DividendsPaidClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_CashFlowsFromUsedInFinancingActivities" xlink:label="ifrs-full_CashFlowsFromUsedInFinancingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IncreaseDecreaseInCashAndCashEquivalents" xlink:label="ifrs-full_IncreaseDecreaseInCashAndCashEquivalents" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_CashAndCashEquivalents" xlink:label="ifrs-full_CashAndCashEquivalents" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ShorttermDepositsClassifiedAsCashEquivalents" xlink:label="ifrs-full_ShorttermDepositsClassifiedAsCashEquivalents" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_InterestIncomeOnLoansAndAdvancesToCustomers" order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_RenteinntekterMaltTilVirkeligVerdi" order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_InterestExpense" order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_NettoRenteinntekter" order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_FeeAndCommissionIncome" order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_FeeAndCommissionExpense" order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherIncome" order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_NettoProvisjonsinntekterOgAndreInntekter" order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_RevenueFromDividends" order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ShareOfProfitLossOfContinuingOperationsOfAssociatesAndJointVenturesAccountedForUsingEquityMethod" order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_GainsLossesOnFinancialAssetsAtFairValueThroughProfitOrLossDesignatedAsUponInitialRecognition" order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_Revenue" order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_EmployeeBenefitsExpense" order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherExpenseByNature" order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_OperatingExpensesBeforeTaxAndImpairment" order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_ProfitLossBeforeTaxAndImpairment" order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ImpairmentLossImpairmentGainAndReversalOfImpairmentLossDeterminedInAccordanceWithIFRS9" order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ProfitLossBeforeTax" order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_IncomeTaxExpenseContinuingOperations" order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_BasicEarningsLossPerShare" order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans" order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_IncomeTaxRelatingToRemeasurementsOfDefinedBenefitPlansOfOtherComprehensiveIncome" order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossBeforeTax" order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherComprehensiveIncomeBeforeTaxFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome" order="24" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLoss" order="25" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_PeriodensUtvidedeResultat" order="26" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_UtvidetResultatUtvannetUtvidetResultat" order="27" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DilutedEarningsLossPerShare" order="28" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_CashAndBankBalancesAtCentralBanks" order="29" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_LoansAndAdvancesToBanks" order="30" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_LoansAndAdvancesToCustomers" order="31" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherDebtInstrumentsHeld" order="32" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_NoncurrentDerivativeFinancialAssets" order="33" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_EquityInstrumentsHeld" order="34" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_InvestmentAccountedForUsingEquityMethod" order="35" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_InvestmentsInSubsidiariesJointVenturesAndAssociates" order="36" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_Goodwill" order="37" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_PropertyPlantAndEquipment" order="38" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherNonfinancialAssets" order="39" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_Assets" order="40" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DepositsFromBanks" order="41" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DepositsFromCustomers" order="42" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_CurrentDebtInstrumentsIssued" order="43" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_NoncurrentDerivativeFinancialLiabilities" order="44" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherLiabilities" order="45" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_SubordinatedLiabilities" order="46" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_Liabilities" order="47" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_IssuedCapital" order="48" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_SharePremium" order="49" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_CapitalReserve" order="50" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_AllocatedToDividendsGifts" order="51" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_HybridCapital" order="52" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_AdditionalPaidinCapital" order="53" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Gavefond" order="54" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome" order="55" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherReserves" order="56" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_EquityAndLiabilities" order="57" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_AdjustmentsForDecreaseIncreaseInTradeAndOtherReceivables" order="58" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_InterestReceivedClassifiedAsOperatingActivities" order="59" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_AdjustmentsForIncreaseDecreaseInDepositsFromCustomers" order="60" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_InterestPaidClassifiedAsOperatingActivities" order="61" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_AdjustmentsForIncreaseDecreaseInDepositsFromBanks" order="62" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_RenteinnbetalingPaLanTilKredittinstitusjoner" order="63" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_AndreRenteutbetalinger" order="64" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Innbetalingsertifikaterogobligasjoner" order="65" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_Utbetalingsertifikaterogobligasjoner" order="66" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_RenteinnbetalingerPaSertifikatOgObligasjoner" order="67" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ReceiptsFromRoyaltiesFeesCommissionsAndOtherRevenue" order="68" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherCashPaymentsFromOperatingActivities" order="69" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_IncomeTaxesPaidRefundClassifiedAsOperatingActivities" order="70" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_CashFlowsFromUsedInOperatingActivities" order="71" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" order="72" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ProceedsFromSalesOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" order="73" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherCashPaymentsToAcquireEquityOrDebtInstrumentsOfOtherEntitiesClassifiedAsInvestingActivities" order="74" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_InnbetalingFraSalgAvLangsiktigeInvesteringerIVerdipapirer" order="75" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DividendsReceivedClassifiedAsInvestingActivities" order="76" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_CashFlowsFromUsedInInvestingActivities" order="77" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ProceedsFromBorrowingsClassifiedAsFinancingActivities" order="78" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_RepaymentsOfBorrowingsClassifiedAsFinancingActivities" order="79" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_InterestPaidClassifiedAsFinancingActivities" order="80" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_NettoInnUtbetalingVedInnskuddFraKredittinstitusjoner" order="81" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_RenteutbetalingPaInnskuddFraKredittinstitusjonar" order="82" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ProceedsFromIssueOfSubordinatedLiabilities" order="83" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLanOgFondsobligasjon" order="84" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ProceedsFromIssueOfRegulatoryCapitalEquity" order="85" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLan" order="86" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_OtherInflowsOutflowsOfCashClassifiedAsInvestingActivities" order="87" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_PaymentsToAcquireOrRedeemEntitysShares" order="88" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ProceedsFromSaleOrIssueOfTreasuryShares" order="89" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DividendsPaidClassifiedAsFinancingActivities" order="90" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_CashFlowsFromUsedInFinancingActivities" order="91" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_IncreaseDecreaseInCashAndCashEquivalents" order="92" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_CashAndCashEquivalents" order="93" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_ShorttermDepositsClassifiedAsCashEquivalents" order="94" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_NameOfParentEntity" xlink:label="ifrs-full_NameOfParentEntity" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DescriptionOfNatureOfEntitysOperationsAndPrincipalActivities" xlink:label="ifrs-full_DescriptionOfNatureOfEntitysOperationsAndPrincipalActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_AddressOfRegisteredOfficeOfEntity" xlink:label="ifrs-full_AddressOfRegisteredOfficeOfEntity" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_PrincipalPlaceOfBusiness" xlink:label="ifrs-full_PrincipalPlaceOfBusiness" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_LegalFormOfEntity" xlink:label="ifrs-full_LegalFormOfEntity" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_CountryOfIncorporation" xlink:label="ifrs-full_CountryOfIncorporation" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_NameOfReportingEntityOrOtherMeansOfIdentification" xlink:label="ifrs-full_NameOfReportingEntityOrOtherMeansOfIdentification" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_NameOfUltimateParentOfGroup" xlink:label="ifrs-full_NameOfUltimateParentOfGroup" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DomicileOfEntity" xlink:label="ifrs-full_DomicileOfEntity" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_NameOfParentEntity" order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DescriptionOfNatureOfEntitysOperationsAndPrincipalActivities" order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_AddressOfRegisteredOfficeOfEntity" order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_PrincipalPlaceOfBusiness" order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_LegalFormOfEntity" order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_CountryOfIncorporation" order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_NameOfReportingEntityOrOtherMeansOfIdentification" order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_NameOfUltimateParentOfGroup" order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="esef_cor_LineItemsNotDimensionallyQualifiedPlaceholder" xlink:to="ifrs-full_DomicileOfEntity" order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
  </definitionLink>
  <definitionLink xlink:role="http://www.sparebank1.no/nb/ostfold-akershus/privat.html/roles/Anchoring" xlink:type="extended" xmlns:xlink="http://www.w3.org/1999/xlink">
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DisclosureOfShareCapitalReservesAndOtherEquityInterestExplanatory" xlink:label="ifrs-full_DisclosureOfShareCapitalReservesAndOtherEquityInterestExplanatory" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Disclosureofcapitalequirements" xlink:label="SB1ostfoldakershus_Disclosureofcapitalequirements" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_DisclosureOfShareCapitalReservesAndOtherEquityInterestExplanatory" xlink:to="SB1ostfoldakershus_Disclosureofcapitalequirements" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InterestIncomeOnLoansAndAdvancesToCustomers" xlink:label="ifrs-full_InterestIncomeOnLoansAndAdvancesToCustomers" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteinntekterMaltTilVirkeligVerdi" xlink:label="SB1ostfoldakershus_RenteinntekterMaltTilVirkeligVerdi" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherIncome" xlink:label="ifrs-full_OtherIncome" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_NettoProvisjonsinntekterOgAndreInntekter" xlink:label="SB1ostfoldakershus_NettoProvisjonsinntekterOgAndreInntekter" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherExpenseByFunction" xlink:label="ifrs-full_OtherExpenseByFunction" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_OperatingExpensesBeforeTaxAndImpairment" xlink:label="SB1ostfoldakershus_OperatingExpensesBeforeTaxAndImpairment" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ProfitLossFromOperatingActivities" xlink:label="ifrs-full_ProfitLossFromOperatingActivities" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_ProfitLossBeforeTaxAndImpairment" xlink:label="SB1ostfoldakershus_ProfitLossBeforeTaxAndImpairment" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DilutedEarningsLossPerShare" xlink:label="ifrs-full_DilutedEarningsLossPerShare" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_UtvidetResultatUtvannetUtvidetResultat" xlink:label="SB1ostfoldakershus_UtvidetResultatUtvannetUtvidetResultat" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherReserves" xlink:label="ifrs-full_OtherReserves" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_AllocatedToDividendsGifts" xlink:label="SB1ostfoldakershus_AllocatedToDividendsGifts" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_HybridCapital" xlink:label="SB1ostfoldakershus_HybridCapital" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Gavefond" xlink:label="SB1ostfoldakershus_Gavefond" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesEquity" xlink:label="ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesEquity" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Implementeringseffekt" xlink:label="SB1ostfoldakershus_Implementeringseffekt" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DividendsRecognisedAsDistributionsToOwnersOfParentRelatingToPriorYears" xlink:label="ifrs-full_DividendsRecognisedAsDistributionsToOwnersOfParentRelatingToPriorYears" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_UtbetaltGaverFor2022" xlink:label="SB1ostfoldakershus_UtbetaltGaverFor2022" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IssueOfConvertibleInstruments" xlink:label="ifrs-full_IssueOfConvertibleInstruments" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_TilbakekjoepHybridkapital" xlink:label="SB1ostfoldakershus_TilbakekjoepHybridkapital" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Korreksjon_til_EK" xlink:label="SB1ostfoldakershus_Korreksjon_til_EK" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InterestReceivedClassifiedAsOperatingActivities" xlink:label="ifrs-full_InterestReceivedClassifiedAsOperatingActivities" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteinnbetalingPaLanTilKredittinstitusjoner" xlink:label="SB1ostfoldakershus_RenteinnbetalingPaLanTilKredittinstitusjoner" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InterestPaidClassifiedAsOperatingActivities" xlink:label="ifrs-full_InterestPaidClassifiedAsOperatingActivities" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_AndreRenteutbetalinger" xlink:label="SB1ostfoldakershus_AndreRenteutbetalinger" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_RepaymentsOfBondsNotesAndDebentures" xlink:label="ifrs-full_RepaymentsOfBondsNotesAndDebentures" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Innbetalingsertifikaterogobligasjoner" xlink:label="SB1ostfoldakershus_Innbetalingsertifikaterogobligasjoner" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Utbetalingsertifikaterogobligasjoner" xlink:label="SB1ostfoldakershus_Utbetalingsertifikaterogobligasjoner" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteinnbetalingerPaSertifikatOgObligasjoner" xlink:label="SB1ostfoldakershus_RenteinnbetalingerPaSertifikatOgObligasjoner" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherCashReceiptsFromSalesOfEquityOrDebtInstrumentsOfOtherEntitiesClassifiedAsInvestingActivities" xlink:label="ifrs-full_OtherCashReceiptsFromSalesOfEquityOrDebtInstrumentsOfOtherEntitiesClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_InnbetalingFraSalgAvLangsiktigeInvesteringerIVerdipapirer" xlink:label="SB1ostfoldakershus_InnbetalingFraSalgAvLangsiktigeInvesteringerIVerdipapirer" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_CashFlowsFromUsedInIncreaseDecreaseInCurrentBorrowings" xlink:label="ifrs-full_CashFlowsFromUsedInIncreaseDecreaseInCurrentBorrowings" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_NettoInnUtbetalingVedInnskuddFraKredittinstitusjoner" xlink:label="SB1ostfoldakershus_NettoInnUtbetalingVedInnskuddFraKredittinstitusjoner" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_InterestPaidClassifiedAsFinancingActivities" xlink:label="ifrs-full_InterestPaidClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteutbetalingPaInnskuddFraKredittinstitusjonar" xlink:label="SB1ostfoldakershus_RenteutbetalingPaInnskuddFraKredittinstitusjonar" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLanOgFondsobligasjon" xlink:label="SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLanOgFondsobligasjon" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLan" xlink:label="SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLan" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_InterestIncomeOnLoansAndAdvancesToCustomers" xlink:to="SB1ostfoldakershus_RenteinntekterMaltTilVirkeligVerdi" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_OtherIncome" xlink:to="SB1ostfoldakershus_NettoProvisjonsinntekterOgAndreInntekter" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_OtherExpenseByFunction" xlink:to="SB1ostfoldakershus_OperatingExpensesBeforeTaxAndImpairment" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossFromOperatingActivities" xlink:to="SB1ostfoldakershus_ProfitLossBeforeTaxAndImpairment" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_DilutedEarningsLossPerShare" xlink:to="SB1ostfoldakershus_UtvidetResultatUtvannetUtvidetResultat" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_OtherReserves" xlink:to="SB1ostfoldakershus_AllocatedToDividendsGifts" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_OtherReserves" xlink:to="SB1ostfoldakershus_HybridCapital" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_OtherReserves" xlink:to="SB1ostfoldakershus_Gavefond" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesEquity" xlink:to="SB1ostfoldakershus_Implementeringseffekt" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_DividendsRecognisedAsDistributionsToOwnersOfParentRelatingToPriorYears" xlink:to="SB1ostfoldakershus_UtbetaltGaverFor2022" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_IssueOfConvertibleInstruments" xlink:to="SB1ostfoldakershus_TilbakekjoepHybridkapital" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesEquity" xlink:to="SB1ostfoldakershus_Korreksjon_til_EK" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_InterestReceivedClassifiedAsOperatingActivities" xlink:to="SB1ostfoldakershus_RenteinnbetalingPaLanTilKredittinstitusjoner" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_InterestPaidClassifiedAsOperatingActivities" xlink:to="SB1ostfoldakershus_AndreRenteutbetalinger" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_RepaymentsOfBondsNotesAndDebentures" xlink:to="SB1ostfoldakershus_Innbetalingsertifikaterogobligasjoner" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_RepaymentsOfBondsNotesAndDebentures" xlink:to="SB1ostfoldakershus_Utbetalingsertifikaterogobligasjoner" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_InterestReceivedClassifiedAsOperatingActivities" xlink:to="SB1ostfoldakershus_RenteinnbetalingerPaSertifikatOgObligasjoner" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_OtherCashReceiptsFromSalesOfEquityOrDebtInstrumentsOfOtherEntitiesClassifiedAsInvestingActivities" xlink:to="SB1ostfoldakershus_InnbetalingFraSalgAvLangsiktigeInvesteringerIVerdipapirer" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInIncreaseDecreaseInCurrentBorrowings" xlink:to="SB1ostfoldakershus_NettoInnUtbetalingVedInnskuddFraKredittinstitusjoner" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_InterestPaidClassifiedAsFinancingActivities" xlink:to="SB1ostfoldakershus_RenteutbetalingPaInnskuddFraKredittinstitusjonar" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_InterestPaidClassifiedAsFinancingActivities" xlink:to="SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLanOgFondsobligasjon" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_InterestPaidClassifiedAsFinancingActivities" xlink:to="SB1ostfoldakershus_RenteutbetalingerPaAnsvarligeLan" order="1" xlink:arcrole="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" priority="1" />
  </definitionLink>
  <definitionLink xlink:role="http://www.sparebank1.no/nb/ostfold-akershus/privat.html/roles/StatementOfChangesInEquity" xlink:type="extended" xmlns:xlink="http://www.w3.org/1999/xlink">
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_StatementOfChangesInEquityAbstract" xlink:label="ifrs-full_StatementOfChangesInEquityAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_StatementOfChangesInEquityTable" xlink:label="ifrs-full_StatementOfChangesInEquityTable" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ComponentsOfEquityAxis" xlink:label="ifrs-full_ComponentsOfEquityAxis" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ComponentsOfEquityDomain" xlink:label="ifrs-full_ComponentsOfEquityDomain" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IssuedCapitalMember" xlink:label="ifrs-full_IssuedCapitalMember" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_MiscellaneousOtherReservesMember" xlink:label="ifrs-full_MiscellaneousOtherReservesMember" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_OtherEquityInterestMember" xlink:label="ifrs-full_OtherEquityInterestMember" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ReserveOfEquityComponentOfConvertibleInstrumentsMember" xlink:label="ifrs-full_ReserveOfEquityComponentOfConvertibleInstrumentsMember" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember" xlink:label="ifrs-full_ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_RetainedEarningsMember" xlink:label="ifrs-full_RetainedEarningsMember" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_SharePremiumMember" xlink:label="ifrs-full_SharePremiumMember" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_StatutoryReserveMember" xlink:label="ifrs-full_StatutoryReserveMember" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_StatementOfChangesInEquityLineItems" xlink:label="ifrs-full_StatementOfChangesInEquityLineItems" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_Equity" xlink:label="ifrs-full_Equity" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IncreaseDecreaseThroughOtherDistributionsToOwners" xlink:label="ifrs-full_IncreaseDecreaseThroughOtherDistributionsToOwners" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IncreaseDecreaseThroughChangeInEquityOfSubsidiaries" xlink:label="ifrs-full_IncreaseDecreaseThroughChangeInEquityOfSubsidiaries" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Implementeringseffekt" xlink:label="SB1ostfoldakershus_Implementeringseffekt" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesEquity" xlink:label="ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesEquity" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_DividendsRecognisedAsDistributionsToOwnersOfParentRelatingToPriorYears" xlink:label="ifrs-full_DividendsRecognisedAsDistributionsToOwnersOfParentRelatingToPriorYears" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_UtbetaltGaverFor2022" xlink:label="SB1ostfoldakershus_UtbetaltGaverFor2022" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_IssueOfConvertibleInstruments" xlink:label="ifrs-full_IssueOfConvertibleInstruments" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_TilbakekjoepHybridkapital" xlink:label="SB1ostfoldakershus_TilbakekjoepHybridkapital" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ProfitLoss" xlink:label="ifrs-full_ProfitLoss" />
    <loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2024-03-27/full_ifrs/full_ifrs-cor_2024-03-27.xsd#ifrs-full_ComprehensiveIncome" xlink:label="ifrs-full_ComprehensiveIncome" />
    <loc xlink:type="locator" xlink:href="SB1ostfoldakershus-2024-12-31.xsd#SB1ostfoldakershus_Korreksjon_til_EK" xlink:label="SB1ostfoldakershus_Korreksjon_til_EK" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityAbstract" xlink:to="ifrs-full_StatementOfChangesInEquityTable" order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" priority="1" xbrldt:contextElement="scenario" xbrldt:closed="true" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityTable" xlink:to="ifrs-full_ComponentsOfEquityAxis" order="0" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ComponentsOfEquityAxis" xlink:to="ifrs-full_ComponentsOfEquityDomain" order="0" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ComponentsOfEquityDomain" xlink:to="ifrs-full_IssuedCapitalMember" order="0" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ComponentsOfEquityDomain" xlink:to="ifrs-full_MiscellaneousOtherReservesMember" order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ComponentsOfEquityDomain" xlink:to="ifrs-full_OtherEquityInterestMember" order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ComponentsOfEquityDomain" xlink:to="ifrs-full_ReserveOfEquityComponentOfConvertibleInstrumentsMember" order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ComponentsOfEquityDomain" xlink:to="ifrs-full_ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember" order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ComponentsOfEquityDomain" xlink:to="ifrs-full_RetainedEarningsMember" order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ComponentsOfEquityDomain" xlink:to="ifrs-full_SharePremiumMember" order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_ComponentsOfEquityDomain" xlink:to="ifrs-full_StatutoryReserveMember" order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityAbstract" xlink:to="ifrs-full_StatementOfChangesInEquityLineItems" order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="ifrs-full_Equity" order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="ifrs-full_IncreaseDecreaseThroughOtherDistributionsToOwners" order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="ifrs-full_IncreaseDecreaseThroughChangeInEquityOfSubsidiaries" order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="SB1ostfoldakershus_Implementeringseffekt" order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesEquity" order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="ifrs-full_DividendsRecognisedAsDistributionsToOwnersOfParentRelatingToPriorYears" order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="SB1ostfoldakershus_UtbetaltGaverFor2022" order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="ifrs-full_IssueOfConvertibleInstruments" order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="SB1ostfoldakershus_TilbakekjoepHybridkapital" order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="ifrs-full_ProfitLoss" order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="ifrs-full_ComprehensiveIncome" order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
    <definitionArc xlink:type="arc" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems" xlink:to="SB1ostfoldakershus_Korreksjon_til_EK" order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" priority="1" />
  </definitionLink>
</linkbase>