<SEC-DOCUMENT>0000314808-18-000034.txt : 20180305
<SEC-HEADER>0000314808-18-000034.hdr.sgml : 20180305
<ACCEPTANCE-DATETIME>20180305161750
ACCESSION NUMBER:		0000314808-18-000034
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180301
FILED AS OF DATE:		20180305
DATE AS OF CHANGE:		20180305

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lowe Patrick Carey
		CENTRAL INDEX KEY:			0001443266

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08097
		FILM NUMBER:		18666234

	MAIL ADDRESS:	
		STREET 1:		6 CHESTERFIELD GARDENS
		STREET 2:		3RD FLOOR
		CITY:			LONDON
		STATE:			X0
		ZIP:			W1J 5BQ

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Ensco plc
		CENTRAL INDEX KEY:			0000314808
		STANDARD INDUSTRIAL CLASSIFICATION:	DRILLING OIL & GAS WELLS [1381]
		IRS NUMBER:				980635229
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6 CHESTERFIELD GARDENS
		CITY:			LONDON
		STATE:			X0
		ZIP:			W1J5BQ
		BUSINESS PHONE:		4402076594660

	MAIL ADDRESS:	
		STREET 1:		6 CHESTERFIELD GARDENS
		CITY:			LONDON
		STATE:			X0
		ZIP:			W1J5BQ

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Ensco International plc
		DATE OF NAME CHANGE:	20091223

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ENSCO INTERNATIONAL INC
		DATE OF NAME CHANGE:	19950526

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ENERGY SERVICE COMPANY INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_152028465622354.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-03-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000314808</issuerCik>
        <issuerName>Ensco plc</issuerName>
        <issuerTradingSymbol>ESV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001443266</rptOwnerCik>
            <rptOwnerName>Lowe Patrick Carey</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6 CHESTERFIELD GARDENS</rptOwnerStreet1>
            <rptOwnerStreet2>3RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>LONDON</rptOwnerCity>
            <rptOwnerState>X0</rptOwnerState>
            <rptOwnerZipCode>W1J 5BQ</rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP &amp; Chief Operating Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2018-03-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3660</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.46</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>362765</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2018-03-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>11285</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.42</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>351480</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person disposed of these shares to an affiliate of the issuer upon the vesting of previously awarded restricted shares.  The purpose of the disposition was to enable the reporting person to satisfy tax withholding obligations that arose upon such vesting, which will be paid to the appropriate taxing authority in cash.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Davor S. Vukadin, by Power of Attorney</signatureName>
        <signatureDate>2018-03-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
