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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-06-25</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001639723</issuerCik>
        <issuerName>Navan, Inc.</issuerName>
        <issuerTradingSymbol>NAVN</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001166586</rptOwnerCik>
            <rptOwnerName>HOROWITZ BENJAMIN A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O NAVAN, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>3045 PARK BOULEVARD</rptOwnerStreet2>
            <rptOwnerCity>PALO ALTO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94306</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-06-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>9959</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10971</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8346792</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Andreessen Horowitz LSV Fund II, L.P.</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6757090</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Andreessen Horowitz LSV Fund I, L.P.</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>607161</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Andreessen Horowitz LSV Fund III, L.P.</value>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2081772</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Andreessen Horowitz Fund V, L.P.</value>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17001</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By CLF Partners, LP</value>
                    <footnoteId id="F8"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10408860</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By AH Parallel Fund V, L.P.</value>
                    <footnoteId id="F9"/>
                    <footnoteId id="F10"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents restricted stock units (&quot;RSUs&quot;), each of which represents a contingent right to receive one share of Issuer's Class A Common Stock. The RSUs are subject to a time-based service condition. The time-based service condition will be satisfied in full on the earlier of (i) the first anniversary of the date of the grant or (ii) the date of Issuer's next annual meeting of stockholders following the date of the grant, subject to Reporting Person's continued service through such vesting date.</footnote>
        <footnote id="F2">Includes 9,959 RSUs, each of which represents a contingent right to receive one share of Issuer's Class A Common Stock upon vesting.</footnote>
        <footnote id="F3">These shares are held of record by Andreessen Horowitz LSV Fund II, L.P. (&quot;AH LSV Fund II&quot;), for itself and as nominee for Andreessen Horowitz LSV Fund II-B, L.P. and Andreessen Horowitz LSV Fund II-Q, L.P. (collectively, the &quot;AH LSV Fund II Entities&quot;). AH Equity Partners LSV II, L.L.C. (&quot;AH EP LSV II &quot;), the general partner of AH LSV Fund II, may be deemed to have sole voting and dispositive power over the shares held by the AH LSV Fund II Entities. The Reporting Person and Marc Andreessen are the managing members of AH EP LSV II and may be deemed to have shared voting and dispositive power over the shares held by the AH LSV Fund II Entities. The Reporting Person disclaims the existence of a &quot;group&quot; and disclaims beneficial ownership of the securities held by the AH LSV Fund II Entities and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.</footnote>
        <footnote id="F4">These shares are held of record by Andreessen Horowitz LSV Fund I, L.P. (&quot;AH LSV Fund I&quot;), for itself and as nominee for Andreessen Horowitz LSV Fund I-B, L.P. and Andreessen Horowitz LSV Fund I-Q, L.P. (collectively, the &quot;AH LSV Fund I Entities&quot;). AH Equity Partners LSV I, L.L.C. (&quot;AH EP LSV I&quot;), the general partner of AH LSV Fund I, may be deemed to have sole voting and dispositive power over the shares held by the AH LSV Fund I Entities. The Reporting Person and Marc Andreessen are the managing members of AH EP LSV I and may be deemed to have shared voting and dispositive power over the shares held by the AH LSV Fund I Entities. The Reporting Person disclaims the existence of a &quot;group&quot; and disclaims beneficial ownership of the securities held by the AH LSV Fund I Entities and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.</footnote>
        <footnote id="F5">These shares are held of record by Andreessen Horowitz LSV Fund III, L.P. (&quot;AH LSV Fund III&quot;), for itself and as nominee for Andreessen Horowitz LSV Fund III-B, L.P., AH 2022 Annual Fund, L.P., AH 2022 Annual Fund-B, L.P., and AH 2022 Annual Fund-QC, L.P. (collectively, the &quot;AH LSV Fund III Entities&quot;). AH Equity Partners LSV III, L.L.C. (&quot;AH EP LSV III&quot;), the general partner of AH LSV Fund III, may be deemed to have sole voting and dispositive power over the shares held by the AH LSV Fund III Entities.</footnote>
        <footnote id="F6">(Continued from Footnote 5) The Reporting Person and Marc Andreessen are the managing members of AH EP LSV III and may be deemed to have shared voting and dispositive power over the shares held by the AH LSV Fund III Entities. The Reporting Person disclaims the existence of a &quot;group&quot; and disclaims beneficial ownership of the securities held by the AH LSV Fund III Entities and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.</footnote>
        <footnote id="F7">These shares are held of record by Andreessen Horowitz Fund V, L.P. (&quot;AH Fund V&quot;), for itself and as nominee for Andreessen Horowitz Fund V-A, L.P., Andreessen Horowitz Fund V-B, L.P. and Andreessen Horowitz Fund V-Q, L.P. (collectively, the &quot;AH Fund V Entities&quot;). AH Equity Partners V, L.L.C. (&quot;AH EP V&quot;), the general partner of AH Fund V, may be deemed to have sole voting and dispositive power over the shares held by the AH Fund V Entities. The Reporting Person and Marc Andreessen are the managing members of AH EP V and may be deemed to have shared voting and dispositive power over the shares held by the AH Fund V Entities. The Reporting Person disclaims the existence of a &quot;group&quot; and disclaims beneficial ownership of the securities held by the AH Fund V Entities and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.</footnote>
        <footnote id="F8">These shares are held of record by CLF Partners, LP (&quot;CLF&quot;). AH EP V, the general partner of CLF, may be deemed to have sole voting and dispositive power over the shares held by CLF. The Reporting Person and Marc Andreessen are the managing members of AH EP V and may be deemed to have shared voting and dispositive power over the shares held by CLF. The Reporting Person disclaims the existence of a &quot;group&quot; and disclaims beneficial ownership of the securities held by CLF and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.</footnote>
        <footnote id="F9">These shares are held of record by AH Parallel Fund V, L.P. (&quot;AH Parallel V&quot;), for itself and as nominee for AH Parallel Fund V-A, L.P., AH Parallel Fund V-B, L.P. and AH Parallel Fund V-Q, L.P. (collectively, the &quot;AH Parallel Fund V Entities&quot;). AH Equity Partners V (Parallel), L.L.C. (&quot;AH EP V Parallel&quot;), the general partner of AH Parallel V, may be deemed to have sole voting and dispositive power over the shares held by the AH Parallel Fund V Entities. The Reporting Person and Marc Andreessen are the managing members of AH EP V Parallel and may be deemed to have shared voting and dispositive power over the shares held by the AH Parallel Fund V Entities.</footnote>
        <footnote id="F10">(Continued from Footnote 9) The Reporting Person disclaims the existence of a &quot;group&quot; and disclaims beneficial ownership of the securities held by the AH Parallel Fund V Entities and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Phil Hathaway, Attorney-in-Fact for Benjamin Horowitz</signatureName>
        <signatureDate>2026-06-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
