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

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-11-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001511737</issuerCik>
        <issuerName>Ubiquiti Networks, Inc.</issuerName>
        <issuerTradingSymbol>UBNT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001486421</rptOwnerCik>
            <rptOwnerName>Summit Partners Private Equity Fund VII-A, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>222 BERKELEY STREET</rptOwnerStreet1>
            <rptOwnerStreet2>18TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</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>0001385242</rptOwnerCik>
            <rptOwnerName>Summit Partners Private Equity Fund VII B L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>222 BERKELEY STREET</rptOwnerStreet1>
            <rptOwnerStreet2>18TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</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>0001494616</rptOwnerCik>
            <rptOwnerName>Summit Investors I (UK), L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>222 BERKELEY STREET, 18TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</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>0001435565</rptOwnerCik>
            <rptOwnerName>Summit Investors I, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>222 BERKELEY STREET, 18TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-11-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1055734</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20095543</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares sold by the following entities: 657,507 shares of common stock sold by Summit Partners Private Equity Fund VII-A, L.P., 394,909 shares of common stock sold by Summit Partners Private Equity Fund VII-B, L.P., 3,033 shares of common stock sold by Summit Investors I, LLC and 285 shares of common stock sold by Summit Investors I (UK), L.P.</footnote>
        <footnote id="F2">Represents shares held by the following entities: 12,515,425 shares of common stock in the name of Summit Partners Private Equity Fund VII-A, L.P., 7,516,964 shares of common stock in the name of Summit Partners Private Equity Fund VII-B, L.P., 57,722 shares of common stock in the name of Summit Investors I, LLC and 5,432 shares of common stock in the name of Summit Investors I (UK), L.P.</footnote>
    </footnotes>

    <remarks>The entities mentioned in Footnote 1 are collectively referred to as the &quot;Summit Entities.&quot;  Each of the Summit Entities disclaims beneficial ownership of all shares except those specifically listed in the Footnotes as held by such entity, except to the extent of each such entity's pecuniary interest therein.</remarks>

    <ownerSignature>
        <signatureName>Summit Partners Private Equity Fund VII-A, L.P., by Summit Partners PE VII, L.P., its GP, by Summit Partners PE VII, LLC, its GP, by Summit Partners, L.P., its GP, by Summit Master Company, LLC, its GP, by Robin W. Devereux, POA for Joseph Trustey, Member</signatureName>
        <signatureDate>2011-11-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Summit Investors I, LLC, by Summit Investors Management, LLC, its manager, by Summit Partners, L.P., its managing member, by Summit Master Company, LLC, its general partner, by Robin W. Devereux, POA for Joseph F. Trustey, Member</signatureName>
        <signatureDate>2011-11-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Summit Investors I (UK), L.P., by Summit Investors Management, LLC, its manager, by Summit Partners, L.P., its managing member, by Summit Master Company, its general Partner, Robin W. Devereux, POA for Joseph F. Trustey, Member</signatureName>
        <signatureDate>2011-11-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Summit Partners Private Equity Fund VII-A, L.P., by Summit Partners PE VII, L.P., its GP, by Summit Partners PE VII, LLC, its GP, by Summit Partners, L.P., its GP, by Summit Master Company, LLC, its GP, by Robin W. Devereux, POA for Joseph Trustey, Member</signatureName>
        <signatureDate>2011-11-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
