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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-10-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0002020385</issuerCik>
        <issuerName>Tavia Acquisition Corp.</issuerName>
        <issuerTradingSymbol>TAVI</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002020381</rptOwnerCik>
            <rptOwnerName>Tavia Sponsor Pte. Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O TAVIA ACQUISITION CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>850 LIBRARY AVENUE, SUITE 204</rptOwnerStreet2>
            <rptOwnerCity>NEWARK</rptOwnerCity>
            <rptOwnerState>DE</rptOwnerState>
            <rptOwnerZipCode>19711</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>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2026-10-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2492440</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1500000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Private Rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2026-10-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>249107</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>24910</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On September 29, 2026, Fog Cutter Holdings LLC, a Delaware limited liability company (the &quot;New Sponsor&quot;), Tavia Acquisition Corp. (the &quot;Issuer&quot;) and Tavia Sponsor Pte. Ltd., a Singapore company (the &quot;Sponsor&quot;), entered into a Purchase and Sponsor Handover Agreement (the &quot;Purchase Agreement&quot;), pursuant to which the New Sponsor agreed to purchase from the Sponsor an aggregate of (i) 2,243,333 ordinary shares, par value $0.0001 per share, of the Issuer (&quot;Ordinary Shares&quot;) and (ii) 249,107 private placement units of the Issuer, each consisting of one Ordinary Share and one right entitling the holder thereof to receive one-tenth (1/10) of one Ordinary Share upon the completion of the Issuer's initial business combination (&quot;Private Rights&quot;), and further agreed to assume certain responsibilities of the Sponsor with respect to the Issuer, as a result of which the New Sponsor would become the sponsor of the Issuer (the &quot;Transaction&quot;).</footnote>
        <footnote id="F2">The Purchase Agreement and the Transaction were approved by the Board of Directors of the Issuer on September 29, 2026. On October 1, 2026, the closing of the Transaction occurred and the New Sponsor became the sponsor of the Issuer, in each case as more fully described in the Issuer's Current Report on Form 8-K (File No. 001-42430) filed with the U.S. Securities and Exchange Commission on October 2, 2026. Following the Transaction, the Sponsor continues to hold 1,500,000 Ordinary Shares (the &quot;Retained Shares&quot;).</footnote>
        <footnote id="F3">The Sponsor was the record holder of each of the reported securities prior to the Transaction and, following the Transaction, continues to be the record holder of the Retained Shares. Kanat Mynzhanov is the controlling shareholder of the Sponsor and holds voting and investment discretion with respect to the securities held by the Sponsor. Mr. Mynzhanov disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein.</footnote>
        <footnote id="F4">As described in the Issuer's Registration Statement on Form S-1 (File No. 333-280275) under the heading &quot;Description of Securities&quot;, each holder of a Private Right will automatically receive one-tenth (1/10) of one Ordinary Share upon consummation of the Issuer's initial business combination, or if the Issuer is not the surviving company in such business combination, each holder of a Private Right will receive one-tenth (1/10) of one Ordinary Share upon affirmative conversion of such right by such holder in connection with the consummation of such business combination. Private Rights have no expiration date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jason T. Simon, Attorney-in-Fact</signatureName>
        <signatureDate>2026-10-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
