Sir Astley Cooper Key (1821 - March 3, 1888), English admiral, was born in London, and entered the navy in 1833.

His father was Charles Aston Key (1793-1849), a well-known surgeon, the pupil of Sir Astley Cooper, and his mother was the latter's niece. After distinguishing himself in active service abroad, on the South American station (1844-1846), in the Baltic during the Crimean War (CB 1855) and China (1857), Key was appointed in 1858 a member of the royal commission on national defence, in 1860 captain of the steam reserve at Devonport, and in 1863 captain of "HMS Excellent" and superintendent of the Royal Naval College.

He had a considerable share in advising as to the reorganization of administration, and in 1866, having become rear-admiral, was made director of naval ordnance. Between 1869 and 1872 he held the offices of superintendent of Portsmouth dockyard, superintendent of Malta dockyard, and second in command in the Mediterranean.

In 1872 he was made president of the projected Royal Naval College at Greenwich, which was organized by him, and after its opening ifl 1873 he was made a KCB and a vice-admiral. In 1876 he was appointed commander-in-chief on the North American and West Indian station. Having become full admiral in 1878, he was appointed in 1879 principal ADC, and soon afterwards first naval lord of the admiralty, retaining this post till 1885. In 1882 he was made GCB. He died at Maidenhead on the 3rd of March, 1888.

See Memoirs of Sir Astley Cooper Key, by Vice-Admiral Colomb (1898).