Captain Sir Joseph Henry Greer (1 February 1855 – 25 August 1933) was an Irish soldier, politician, and racing horse owner and breeder. He was born in County Tyrone, was educated at Wellington and joined the 7th Highlanders after military college. He was appointed as Director of the Irish National Stud in 1915. He also became the Aga Khan III's first stud manager. He received a knighthood in 1925.