Jack O'Neill is a fictional character in the Stargate film and television series . Jack O'Neill may also refer to: Jack O'Neill (baseball) (1873–1935), Irish-American baseball player Jack O'Neill (businessman) (1923–2017), American surfer and businessman, founder of O'Neill, the surfwear and equipment brand Jack O'Neill (statistician) (1910–1998), Australian public servant Jack O'Neill, American rock musician, member of Jackopierce See also John O'Neill (disambiguation)