X0303 5 2010-12-31 0 0 0000314808 Ensco plc ESV 0001463780 O'Neill Sean Patrick 500 N. AKARD STREET SUITE 4300 DALLAS TX 75201-3331 0 1 0 0 Vice President American Depositary Shares 2010-12-31 5 A 0 131.7013 43.40 A 186.0622 I Ensco Savings Plan Amount is representative of Ensco American Depositary Shares acquired, and held indirectly, via the Ensco Savings Plan as of December 31, 2010. Amount is representative of Ensco American Depositary Shares acquired, and held indirectly, through normal payroll contributions to the Ensco Savings Plan for the months of January through December 2010. Price of Securities dependent upon trading price applicable on date of future transactions. The average cost/price is representative of all benefically, indirectly owned securities acquired via normal payroll contributions to the Ensco Savings Plan. /s/ Sean P. O'Neill 2011-01-18