• John O'Neil (painter), American painter and writer
• John O'Neil (footballer)
  John O'Neil (footballer)
  John Thomas O'Neil is a Scottish former professional association football player. He represented Scotland once, and played for Dundee United, St. Johnstone, Hibernian and Falkirk in the top division.-Career:...
  
  , Scottish footballer
• John O'Neil (USA rugby player), American rugby union player
• John O'Neil (baseball), American baseball player
• Buck O'Neil
  Buck O'Neil
  John Jordan "Buck" O'Neil was a first baseman and manager in the Negro American League, mostly with the Kansas City Monarchs. After his playing days, he worked as a scout, and became the first African American coach in Major League Baseball...
  
  , full name John Jordan O'Neil, American baseball player

See also

• John O'Neill (disambiguation)
  John O'Neill (disambiguation)
  - Politics :*John O'Neill , political philosopher, Professor of Political Economy at the University of Manchester*John O'Neill , U.S...
  
  
• John H. O'Neall
  John H. O'Neall
  John Henry O'Neall was a U.S. Representative from Indiana.Born in Newberry, South Carolina, O'Neall was left an orphan when eight years of age and was reared by his grandfather, who resided in Daviess County, Indiana....
  
  , U.S. Representative from Indiana
• John O'Neal
  John O'Neal
  John O'Neal a native of Ireland, was a United States Navy sailor who received the Medal of Honor for heroism on April 12, 1872.-Medal of Honor citation:...
  
  , U.S. sailor who was awarded the Medal of Honor
• Johnny O'Neal
  Johnny O'Neal
  Johnny O'Neal, born October 10, 1956 in Detroit, Michigan, is an American Neo-bop jazz pianist. His playing ranges from the technically virtuosic to the tenderest of ballad interpretations. Though unique in style, he is influenced by many jazz elders, including Oscar Peterson and Art Tatum. He has...
  
  , American pianist