<SEC-DOCUMENT>0000314808-18-000029.txt : 20180305
<SEC-HEADER>0000314808-18-000029.hdr.sgml : 20180305
<ACCEPTANCE-DATETIME>20180305161610
ACCESSION NUMBER:		0000314808-18-000029
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:			Darby Tommy
		CENTRAL INDEX KEY:			0001719757

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08097
		FILM NUMBER:		18666206

	MAIL ADDRESS:	
		STREET 1:		5847 SAN FELIPE
		STREET 2:		SUITE 3300
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77057

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_152028455256924.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>0001719757</rptOwnerCik>
            <rptOwnerName>Darby Tommy</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5847 SAN FELIPE ST.</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3300</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77057</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Controller</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>95</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.46</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12956</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Ordinary Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17205</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Represents shares held by an immediate family member</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </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>
