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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-09-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0002085659</issuerCik>
        <issuerName>Silicon Valley Acquisition Corp.</issuerName>
        <issuerTradingSymbol>SVAQU</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002101202</rptOwnerCik>
            <rptOwnerName>SILICON VALLEY ACQUISITION SPONSOR LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O SILICON VALLEY ACQUISITION CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>425 PAGE MILL RD., SUITE 200, 2ND FLOOR</rptOwnerStreet2>
            <rptOwnerCity>PALO ALTO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94306</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002076157</rptOwnerCik>
            <rptOwnerName>Nash Daniel Benjamin</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O SILICON VALLEY ACQUISITION CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>425 PAGE MILL RD., SUITE 200, 2ND FLOOR</rptOwnerStreet2>
            <rptOwnerCity>PALO ALTO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94306</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B ordinary shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2026-09-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>500000</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A ordinary shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>500000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6665950</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">As described in the Issuer's registration statement on Form S-1 (File No. 333-290366) (the &quot;Registration Statement&quot;) under the heading &quot;Description of Securities&quot;, the Class B ordinary shares will automatically convert into Class A ordinary shares at the time of the Issuer's initial business combination, or earlier at the option of the holder, on a one-for-one basis, subject to certain adjustments described therein and have no expiration date.</footnote>
        <footnote id="F2">Silicon Valley Acquisition Sponsor LLC (the &quot;Sponsor&quot;) transferred 500,000 Class B ordinary shares to an institutional investor at no cost (the &quot;Transfer&quot;), pursuant to the terms and conditions of that certain Founder Shares Transfer Agreement, dated as of September 17, 2026, by and among the Sponsor, the Issuer and the institutional investor. The Transfer was made in connection with a note financing for the target in connection with the Issuer's proposed business combination, as further described in the Issuer's Current Report on Form 8-K, filed on September 18, 2026.</footnote>
        <footnote id="F3">The Sponsor is the record holder of such securities. Dan Nash is the managing member of the Sponsor, and as such, has voting and investment discretion with respect to, and may be deemed to have beneficial ownership of, the securities held by the Sponsor. Mr. Nash disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Tricia Branker, Attorney-in-Fact</signatureName>
        <signatureDate>2026-09-21</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Tricia Branker, Attorney-in-Fact</signatureName>
        <signatureDate>2026-09-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
