<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0607</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2026-03-18</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001071321</issuerCik>
        <issuerName>TURKCELL ILETISIM HIZMETLERI A S</issuerName>
        <issuerTradingSymbol>TKC</issuerTradingSymbol>
        <issuerForeignTradingSymbol>TCELL</issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002120340</rptOwnerCik>
            <rptOwnerName>Inci Mehmet Naci</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>true</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>AYDINEVLER MAHALLESI</rptOwnerStreet1>
            <rptOwnerStreet2>INONU CADDESI NO: 20 B BLOK KUCUKYALI</rptOwnerStreet2>
            <rptOwnerCity>ISTANBUL</rptOwnerCity>
            <rptOwnerNonUSStateTerritory></rptOwnerNonUSStateTerritory>
            <rptOwnerCountry>W8</rptOwnerCountry>
            <rptOwnerZipCode>34854</rptOwnerZipCode>
            <rptOwnerStateDescription>TURKEY</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <remarks>Exhibit List - Exhibit 24 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Beren Erdem Hamaratgil, Attorney-in-Fact</signatureName>
        <signatureDate>2026-03-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
