Old Jack may refer to:
Nickname John Driscoll (), Australian jockey J. T. Hearne (1867–1944), English cricketer Jacques Henry (1942–2016), French private rally driver Jack Hinson (c. 1807–1874), American farmer and Civil War Confederate sniper Stonewall Jackson (1824–1863), Confederate general during the Civil War Mildirn (c. 1835–c. 1914), Aboriginal leader, translator and advisor also called Old Jack Davis Carbine (horse) (1885–1914), New Zealand-bred Thoroughbred race horse
Arts and entertainment Old Jack (album), the first album from Brazilian blues/rock band O Bando do Velho Jack, recorded in 1998 the title character of Old Jack's Boat, a British pre-school children's television series (2013–2015)