Jack O'Connor
- Given Name
- John Joseph
- Nickname(s)
- Rowdy Jack, Peach Pie, Oak
- Born
- 6/2/1866 — St. Louis, MO, USA
- Died
- 11/14/1937 — St. Louis, MO, USA
- Weight
- 170 lbs
- Height
- 5' 10"
- Throws
- R
- Bats
- R
- Team(s)
- Cincinnati Red Stockings (1887–1888)Columbus Solons (1889–1891)Cleveland Spiders (1892–1898)St. Louis Perfectos (1899)Pittsburgh Pirates (1900–1902)St. Louis Cardinals (1900)New York Highlanders (1903)St. Louis Browns (1904–1910)
- Debut
- 1887-04-20
- Final Game
- 1910-10-09