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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-09-18</periodOfReport>

    <issuer>
        <issuerCik>0001531031</issuerCik>
        <issuerName>Esquire Financial Holdings, Inc.</issuerName>
        <issuerTradingSymbol>ESQ</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001709867</rptOwnerCik>
            <rptOwnerName>Sagliocca Andrew C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>100 JERICHO QUADRANGLE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>JERICHO</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11753</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <officerTitle>Vice Chairman, President &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-09-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>122.73</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>288798</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $122.61 to $123.50, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (1) to this Form 4.</footnote>
        <footnote id="F2">Includes shares of restricted stock which vest in three equal annual installments commencing on December 16, 2024.</footnote>
        <footnote id="F3">Includes shares of restricted stock which vest in three equal annual installments commencing on December 9, 2025.</footnote>
        <footnote id="F4">Includes shares of restricted stock which vest in three equal annual installments commencing on December 19, 2026.</footnote>
        <footnote id="F5">Includes shares of restricted stock which vest in three equal annual installments commencing on December 15, 2027.</footnote>
        <footnote id="F6">Includes shares of restricted stock which vest in three equal annual installments commencing on January 30, 2028.</footnote>
        <footnote id="F7">Includes shares of restricted stock which vest in three equal annual installments commencing on January 29, 2029.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Eric S. Bader, pursuant to power of attorney</signatureName>
        <signatureDate>2026-09-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
