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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-03-04</periodOfReport>

    <issuer>
        <issuerCik>0001844505</issuerCik>
        <issuerName>QT IMAGING HOLDINGS, INC.</issuerName>
        <issuerTradingSymbol>QTI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002013328</rptOwnerCik>
            <rptOwnerName>McMorrow Gerald</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O QT IMAGING HOLDINGS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>3 HAMILTON LANDING, SUITE 160</rptOwnerStreet2>
            <rptOwnerCity>NOVATO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94949</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-03-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5904</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5904</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Received in exchange for 17,226 shares of QT Imaging, Inc. (&quot;QT Imaging&quot;) in connection with the merger of QT Imaging into a subsidiary of QT Imaging Holdings, Inc. (the &quot;Company&quot;) pursuant to the exchange ratio set forth in the business combination agreement between QT Imaging and the Company. The closing price of the Company's Common Stock on the effective date of the merger was $3.53.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Gerald McMorrow</signatureName>
        <signatureDate>2024-03-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
