Admiral Sir William Henry Dillon (8 August 1779 - 9 September 1857) was a British naval officer. He was born in Birmingham in 1779, illegitimate son of Sir John Talbot Dillon, and Elizabeth Collins. He entered the navy in May 1790 and served as a midshipman under Captain Gambier in Defence, and was stunned by a splinter in the action of 1 June 1794. He was present in Lord Bridport's action off Ile de Groix on 23 June 1795, and at the reduction of St. Lucie in May 1796, when he carried a flag of truce to take possession of Pigeon Island. Having become an acting-lieutenant in Glenmore in 1798, he co-operated with the army at Wexford during the rebellion, where he succeeded in arresting the Irish chief Skallian.