<SEC-DOCUMENT>0001749118-18-000008.txt : 20180912
<SEC-HEADER>0001749118-18-000008.hdr.sgml : 20180912
<ACCEPTANCE-DATETIME>20180912205734
ACCESSION NUMBER:		0001749118-18-000008
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180910
FILED AS OF DATE:		20180912
DATE AS OF CHANGE:		20180912

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Scolnick Kathryn R.
		CENTRAL INDEX KEY:			0001749118

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31560
		FILM NUMBER:		181067793

	MAIL ADDRESS:	
		STREET 1:		10200 S. DE ANZA BOULEVARD
		CITY:			CUPERTINO
		STATE:			CA
		ZIP:			95014

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Seagate Technology plc
		CENTRAL INDEX KEY:			0001137789
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER STORAGE DEVICES [3572]
		IRS NUMBER:				980648577
		STATE OF INCORPORATION:			L2
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		38/39 FITZWILLIAM SQUARE
		CITY:			DUBLIN 2
		STATE:			L2
		ZIP:			00000
		BUSINESS PHONE:		(353) (1) 234-3136

	MAIL ADDRESS:	
		STREET 1:		38/39 FITZWILLIAM SQUARE
		CITY:			DUBLIN 2
		STATE:			L2
		ZIP:			00000

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Seagate Technology
		DATE OF NAME CHANGE:	20090330

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SEAGATE TECHNOLOGY
		DATE OF NAME CHANGE:	20021212

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SEAGATE TECHNOLOGY HOLDINGS
		DATE OF NAME CHANGE:	20010406
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_153680023829455.xml
<DESCRIPTION>FORM 4
<TEXT>
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    <periodOfReport>2018-09-10</periodOfReport>

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    <issuer>
        <issuerCik>0001137789</issuerCik>
        <issuerName>Seagate Technology plc</issuerName>
        <issuerTradingSymbol>STX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001749118</rptOwnerCik>
            <rptOwnerName>Scolnick Kathryn R.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10200 S. DE ANZA BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CUPERTINO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95014</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Interim CFO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
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            <securityTitle>
                <value>Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2018-09-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>1678</value>
                </transactionShares>
                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4569.0198</value>
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                    <value>D</value>
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    <derivativeTable>
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                    <value>1678.0</value>
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                <transactionCode>A</transactionCode>
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            <transactionAmounts>
                <transactionShares>
                    <value>19885</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
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                    <value>19885</value>
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                    <value>D</value>
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        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Share Unit</value>
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            <conversionOrExercisePrice>
                <value>0.0</value>
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            <transactionDate>
                <value>2018-09-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10738</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
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                <footnoteId id="F5"/>
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                <footnoteId id="F5"/>
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                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
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                    <value>10738.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>10738</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These Ordinary Shares are withheld securities to cover tax liabilities incident to the vesting of Restricted Share Units (&quot;RSUs&quot;).</footnote>
        <footnote id="F2">Each RSU represents a contingent right to receive one Ordinary Share of the Issuer.</footnote>
        <footnote id="F3">The RSUs originally granted to the Reporting Person under the Seagate Technology plc 2012 Equity Incentive Plan (the &quot;Plan&quot;) for 6,715 shares, vest as to one-quarter of the shares on September 11, 2018 and each one-year anniversary thereafter.</footnote>
        <footnote id="F4">Consists of a grant of RSUs awarded to the Reporting Person as a special equity award in the amount of 19,885 shares under the Plan.  Subject to the Reporting Person's continuous employment, such RSUs vest as to one-quarter of the shares on September 10, 2019 and each one-year anniversary thereafter.</footnote>
        <footnote id="F5">Consists of a grant of RSUs awarded to the Reporting Person under the  Plan in the amount of 10,738. Subject to the Reporting Person's continuous employment, such RSUs vest as to one-quarter of the shares on September 10, 2019 and each one-year anniversary thereafter.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Laurie Webb Attorney-in-Fact for Kathryn R. Scolnick</signatureName>
        <signatureDate>2018-09-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
