Career
O'Neill was a switch-hitter and threw right-handed. He was born in Saint John, New Brunswick, Canada. Playing at shortstop in his 1904 rookie season for the Red Sox, O'Neill committed six errors during a 13-inning 5-3 loss to the St Louis Browns on May 21 to become the only 20th century Major League player to record six errors in a game.
In the midseason he was traded to Washington in the same transaction that brought Kip Selbach to Boston. In a two-season career, O'Neill was a .243 hitter with two home runs and 42 RBI in 206 games played. O'Neill died in Woodhaven, New York, at the age of 40.