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

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2009-12-17</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001080359</issuerCik>
        <issuerName>ALLOY INC</issuerName>
        <issuerTradingSymbol>ALOY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001161175</rptOwnerCik>
            <rptOwnerName>KLEINHEINZ CAPITAL PARTNERS, INC.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>301 COMMERCE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1900</rptOwnerStreet2>
            <rptOwnerCity>FORT WORTH</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>76102</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of a 13(d) 10% Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001421810</rptOwnerCik>
            <rptOwnerName>Kleinheinz Capital Partners LDC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WALKERS SPV LTD.</rptOwnerStreet1>
            <rptOwnerStreet2>WALKER HOUSE, 87 MARY STREET</rptOwnerStreet2>
            <rptOwnerCity>GEORGE TOWN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>KY1-9001</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of a 13(d) 10% Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001165595</rptOwnerCik>
            <rptOwnerName>GLOBAL UNDERVALUED SECURITIES MASTER FUND LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BNY MELLON ALTERNATIVE INVESTMENT SE</rptOwnerStreet1>
            <rptOwnerStreet2>48 PAR LA VILLE ROAD SUITE 464</rptOwnerStreet2>
            <rptOwnerCity>HAMILTON HMII</rptOwnerCity>
            <rptOwnerState>D0</rptOwnerState>
            <rptOwnerZipCode>0000</rptOwnerZipCode>
            <rptOwnerStateDescription>BERMUDA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of a 13(d) 10% Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001306112</rptOwnerCik>
            <rptOwnerName>Global Undervalued Securities Fund Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BNY MELLON ALTERNATIVE INVESTMENT SE</rptOwnerStreet1>
            <rptOwnerStreet2>48 PAR LA VILLE ROAD SUITE 464</rptOwnerStreet2>
            <rptOwnerCity>HAMILTON HM 11 BERMUDA</rptOwnerCity>
            <rptOwnerState>D0</rptOwnerState>
            <rptOwnerZipCode>00000</rptOwnerZipCode>
            <rptOwnerStateDescription>BERMUDA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of a 13(d) 10% Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001081865</rptOwnerCik>
            <rptOwnerName>KLEINHEINZ JOHN B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>301 COMMERCE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1900</rptOwnerStreet2>
            <rptOwnerCity>FORT WORTH</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>76102</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of a 13(d) 10% Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001090351</rptOwnerCik>
            <rptOwnerName>GLOBAL UNDERVALUED SECURITIES FUND LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BNY MELLON ALTERNATIVE INVESTMENT SE</rptOwnerStreet1>
            <rptOwnerStreet2>48 PAR LA VILLE ROAD SUITE 464</rptOwnerStreet2>
            <rptOwnerCity>HAMILTON</rptOwnerCity>
            <rptOwnerState>D0</rptOwnerState>
            <rptOwnerZipCode>HM11</rptOwnerZipCode>
            <rptOwnerStateDescription>BERMUDA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of a 13(d) 10% Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001302660</rptOwnerCik>
            <rptOwnerName>Global Undervalued Securities Fund QP L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BNY MELLON ALTERNATIVE INVESTMENT SE</rptOwnerStreet1>
            <rptOwnerStreet2>48 PAR LA VILLE ROAD SUITE 464</rptOwnerStreet2>
            <rptOwnerCity>HAMILTON N H 11</rptOwnerCity>
            <rptOwnerState>D0</rptOwnerState>
            <rptOwnerZipCode>00000</rptOwnerZipCode>
            <rptOwnerStateDescription>BERMUDA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of a 10% Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>402061</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of common stock (&quot;Common Stock&quot;) of Alloy, Inc. (the &quot;Issuer&quot;) directly beneficially owned by Global Undervalued Securities Master Fund, L.P. (&quot;Global Master&quot;).</footnote>
        <footnote id="F2">On December 17, 2009, Kleinheinz Capital Partners, Inc. (&quot;Kleinheinz&quot;), Kleinheinz Capital Partners LDC (&quot;LDC&quot;), Global Undervalued Securities Fund, L.P. (&quot;Global, L.P.&quot;), Global Undervalued Securities Fund (QP), L.P. (&quot;Global QP&quot;), Global Undervalued Securities Fund, Ltd. (&quot;Global Ltd.&quot;), Global Master and John B. Kleinheinz (&quot;Mr. Kleinheinz&quot;, and collectively with Kleinheinz, LDC, Global, L.P., Global QP, Global Ltd. and Global Master, the &quot;Reporting Perons&quot;) and BD Media Investors LP, SRB Greenway Opportunity Fund, (QP), L.P., SRB Greenway Opportunity Fund, L.P., SRB Management, L.P., BC Advisors, LLC, Steven R. Becker and Matthew A. Drapkin (the &quot;Greenway Parties&quot;) entered into a Joint Filing Agreement (the &quot;Joint Filing Agreement&quot;).  Pursuant to the Joint Filing Agreement, the Reporting Persons and the Greenway Parties agreed to coordinate their actions with respect to the purchase and sale of Common Stock and discussions over certain matters with the Issuer.</footnote>
        <footnote id="F3">As a result of the agreements contained in the Joint Filing Agreement, the Reporting Persons may be deemed to be members of a &quot;group&quot; for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;) with the Greenway Parties, and, therefore, may be deemed to beneficially own Common Stock beneficially owned by the Greenway Parties.  The Reporting Persons disclaim beneficial ownership of and pecuniary interest in any shares of Common Stock beneficially owned by the Greenway Parties.  This Form 3 and the filing hereof shall not be deemed an admission that any Reporting Person is a beneficial owner of any shares of Common Stock for any purpose, other than the Common Stock reported in Table 1, or that any Reporting Person is a member of a &quot;group&quot;.  This Form 3 does not reflect any Common Stock owned by the Greenway Parties.</footnote>
        <footnote id="F4">Kleinheinz, as the investment manager of Global, L.P., Global QP, Global Ltd. and Global Master; LDC, as the general partner of Global, L.P. and Global QP; Global, L.P., as a general partner of Global Master; Global QP, as a general partner of Global Master; Global Ltd., as a general partner of Global Master; and Mr. Kleinheinz as the sole director and President of Kleinheinz and a director of LDC, may in each case be deemed to be beneficial owners of the securities reported herein for purposes of Rule 16a-1(a) of the Exchange Act.  Kleinheinz, LDC, Global, L.P., Global QP, Global Ltd. and Mr. Kleinheinz disclaim any beneficial ownership of any Common Stock listed herein, except to the extent of any pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>see Exhibiit 99.1</signatureName>
        <signatureDate>2009-12-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
