John Charles O'Connor (December 1, 1891 – May 30, 1982) was an Irish born Major League Baseball player.

Nicknamed "Bucky", he played one game at catcher for the Chicago Cubs on September 16, 1916.

The game was against the Philadelphia Phillies and it was played at the Baker Bowl stadium.

In the game, O'Connor replaced the Cubs' Rowdy Elliott after he "split" his finger on a foul tip.

The Cubs' other catchers, Jimmy Archer and Art Wilson, were themselves injured.