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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-08-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001653384</issuerCik>
        <issuerName>Runway Growth Credit Fund Inc.</issuerName>
        <issuerTradingSymbol>NONE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001704381</rptOwnerCik>
            <rptOwnerName>Retirement Plan of Carilion Clinic</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>213 SOUTH JEFFERSON STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 807</rptOwnerStreet2>
            <rptOwnerCity>ROANOKE</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>24011</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2017-08-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>258802.6</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>591247.2</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>Thomas B. Raterman is signing on behalf of Retirement Plan of Carilion Clinic pursuant to the power of attorney dated April 21, 2017, which was previously filed with the Securities and Exchange Commission as an exhibit to the Form 3 filed by Retirement Plan of Carilion Clinic on April 21, 2017.</remarks>

    <ownerSignature>
        <signatureName>/s/ Thomas B. Raterman, on behalf of Retirement Plan of Carilion Clinic</signatureName>
        <signatureDate>2017-09-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
