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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2024-02-05</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001293613</issuerCik>
        <issuerName>Kayne Anderson Energy Infrastructure Fund, Inc.</issuerName>
        <issuerTradingSymbol>KYN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002025837</rptOwnerCik>
            <rptOwnerName>Little Harrison James</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O KAYNE ANDERSON CAPITAL ADVISORS, LP</rptOwnerStreet1>
            <rptOwnerStreet2>717 TEXAS AVENUE, 22ND FLOOR</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77002</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <ownerSignature>
        <signatureName>/s/ Harrison J. Little</signatureName>
        <signatureDate>2024-10-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
