James Albert Edward Hamilton, 3rd Duke of Abercorn, KG, KP, PC (30 November 1869 – 12 September 1953), styled Marquess of Hamilton between 1885 and 1913, was a British peer and Unionist politician. He was the first Governor of Northern Ireland, a post he held between 1922 and 1945. He was a great-grandfather of Diana, Princess of Wales.