Mike O'Neill, Irish-American baseball player and manager (d. 1959)

Michael Joyce O'Neill (5 October 1877 – 12 August 1959) was a starting pitcher and left fielder in Major League Baseball. From 1901 through 1907, he played for the St. Louis Cardinals (1901–04) and Cincinnati Reds (1907). O'Neill batted and threw right-handed. A native of Maam, Ireland, he played as Michael Joyce in his 1901 rookie year with the Cardinals.