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

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    <periodOfReport>2021-01-07</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000098246</issuerCik>
        <issuerName>TIFFANY &amp; CO</issuerName>
        <issuerTradingSymbol>TIF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001112072</rptOwnerCik>
            <rptOwnerName>FARAH ROGER N</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>TIFFANY &amp; CO.</rptOwnerStreet1>
            <rptOwnerStreet2>727 FIFTH AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Chairman of the Board</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

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            <securityTitle>
                <value>Common Stock $.01 Par</value>
            </securityTitle>
            <transactionDate>
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            </transactionDate>
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                <equitySwapInvolved>0</equitySwapInvolved>
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                <transactionShares>
                    <value>25409</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>131.50</value>
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                </transactionPricePerShare>
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                <transactionCode>D</transactionCode>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Family Trust</value>
                </natureOfOwnership>
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    <derivativeTable>
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            <securityTitle>
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                <value>2029-06-04</value>
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                <underlyingSecurityTitle>
                    <value>Common Stock $.01 Par</value>
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                <value>2021-01-07</value>
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                <transactionShares>
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            <expirationDate>
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                <underlyingSecurityTitle>
                    <value>Common Stock $.01 Par</value>
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        <derivativeTransaction>
            <securityTitle>
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                <value>85.82</value>
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                <value>2021-01-07</value>
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                    <value>D</value>
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            <exerciseDate>
                <footnoteId id="F2"/>
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            <expirationDate>
                <value>2027-05-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock $.01 Par</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6749.0</value>
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        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Disposed of pursuant to the Amended and Restated Agreement and Plan of Merger, dated as of October 28, 2020, by and among Tiffany &amp; Co. (the &quot;Company&quot;), LVMH Moet Hennessy-Louis Vuitton SE (&quot;Parent&quot;), Breakfast Holdings Acquisition Corp. (&quot;Holding&quot;) and Breakfast Acquisition Corp. (&quot;Merger Sub&quot;) (the &quot;Merger Agreement&quot;), which amended and restated the Agreement and Plan of Merger, dated as of November 24, 2019, by and among the Company, Parent, Holding and Merger Sub, in exchange for $131.50 per share in cash, without interest and less any required withholding taxes (the &quot;Per Share Merger Consideration&quot;). The total number of shares disposed of included 10,355 unvested restricted stock units (&quot;RSUs&quot;), and 5,054 vested RSUs (which includes dividend equivalent units credited in respect of such vested RSUs) as to which the director elected to defer the maturity date (and thereby the delivery of the related shares).</footnote>
        <footnote id="F2">Pursuant to the Merger Agreement, each outstanding option, whether vested or unvested, was canceled and converted into the right to receive an amount in cash, without interest and less any required withholding taxes, equal to the product of (i) the excess, if any, of (A) the Per Share Merger Consideration over (B) the per-share exercise price for such option, multiplied by (ii) the total number of shares underlying such option.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Catherine W.H. So, Attorney-in-Fact</signatureName>
        <signatureDate>2021-01-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0306
4
2021-01-07
1
0000098246
TIFFANY & CO
TIF
0001112072
FARAH ROGER N
TIFFANY & CO.
727 FIFTH AVENUE
NEW YORK
NY
10022
1
0
0
1
Chairman of the Board
Common Stock $.01 Par
2021-01-07
4
D
0
25409
131.50
D
0
D
Common Stock $.01 Par
2021-01-07
4
D
0
10000
131.50
D
0
I
By Family Trust
Non-Qualified Stock Option (Right to Buy)
93.53
2021-01-07
4
D
0
9489
D
2029-06-04
Common Stock $.01 Par
9489.0
0
D
Non-Qualified Stock Option (Right to Buy)
126.44
2021-01-07
4
D
0
8395
D
2028-05-24
Common Stock $.01 Par
8395.0
0
D
Non-Qualified Stock Option (Right to Buy)
85.82
2021-01-07
4
D
0
6749
D
2027-05-25
Common Stock $.01 Par
6749.0
0
D
Disposed of pursuant to the Amended and Restated Agreement and Plan of Merger, dated as of October 28, 2020, by and among Tiffany & Co. (the "Company"), LVMH Moet Hennessy-Louis Vuitton SE ("Parent"), Breakfast Holdings Acquisition Corp. ("Holding") and Breakfast Acquisition Corp. ("Merger Sub") (the "Merger Agreement"), which amended and restated the Agreement and Plan of Merger, dated as of November 24, 2019, by and among the Company, Parent, Holding and Merger Sub, in exchange for $131.50 per share in cash, without interest and less any required withholding taxes (the "Per Share Merger Consideration"). The total number of shares disposed of included 10,355 unvested restricted stock units ("RSUs"), and 5,054 vested RSUs (which includes dividend equivalent units credited in respect of such vested RSUs) as to which the director elected to defer the maturity date (and thereby the delivery of the related shares).
Pursuant to the Merger Agreement, each outstanding option, whether vested or unvested, was canceled and converted into the right to receive an amount in cash, without interest and less any required withholding taxes, equal to the product of (i) the excess, if any, of (A) the Per Share Merger Consideration over (B) the per-share exercise price for such option, multiplied by (ii) the total number of shares underlying such option.
/s/ Catherine W.H. So, Attorney-in-Fact
2021-01-11