Captain William Evelyn Denison (25 February 1843 – 24 September 1916) was a British Army officer and a Conservative Party politician. He owned an estate in Ossington, Nottinghamshire where he held several local offices as well as sitting in the House of Commons from 1874 to 1880.
Denison was the eldest son of Sir William T. Denison (1804–71), a British colonial governor and brother of Speaker Evelyn Denison. His mother was Caroline née Hornby, daughter of Admiral Sir Phipps Hornby. At the age of 3 he moved to Van Diemen's Land, where his father had been appointed Lieutenant-Governor. In 1854 Sir William was promoted to Governor of New South Wales, and the family moved to Sydney.
William was educated at Eton and then at the Royal Military Academy in Woolwich. In February 1864 he was commissioned as a Lieutenant in the Royal Artillery, and in September 1876 he was promoted to the rank of Captain. He retired from the Royal Artillery in 1878.
Denison was elected at the 1874 general election as a Member of Parliament (MP) for Nottingham, when the Conservatives took both the city's parliamentary seats from the Liberals. Denison did not stand again in Nottingham at the 1880 general election, having been asked instead to contest the Northern division of Nottinghamshire, where he was unsuccessful.