John O'Neil may refer to:
John O'Neil (painter) (1915–2004), American painter and writer John O'Neil (footballer) (born 1971), Scottish footballer John O'Neil (rugby union) (1898–1950), American rugby union player John O'Neil (rugby league), English rugby league footballer who played in the 1950s and 1960s John O'Neil (baseball) (1920–2012), American baseball player John G. A. O'Neil (1937–1992), American politician from New York John O'Neil (priest), Irish Anglican priest John E. O'Neil IV, U.S. Army officer John Jordan O'Neil, better known as Buck O'Neil (1911–2006), American baseball player
Fictional characters Mr. John O'Neil, a Teenage Mutant Ninja Turtles character
See also John O'Neill (disambiguation) John O'Neal (disambiguation)