X0306 4 2012-07-31 0000314808 Ensco plc ESV 0001495170 Knowlton John Stokes 5847 SAN FELIPE SUITE 3300 HOUSTON TX 77057 0 1 0 0 Sr. Vice President - Technical Class A Ordinary Shares 2012-07-31 4 F 0 2867 54.33 D 59296 D Class A Ordinary Shares 163 I Ensco Savings and Retirement Plans 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 by the issuer to the Internal Revenue Service in cash. /s/ Elizabeth Wright 2012-08-02