John Warren Merson (January 17, 1922 – April 28, 2000) was an American professional baseball player. The second baseman and third baseman appeared in 125 games in the Major Leagues for the Pittsburgh Pirates and the Boston Red Sox—124 of them for the Pirates. During the 1952 off-season, the Red Sox took Merson in the Rule 5 draft. Merson appeared in one game for Boston in 1953 before being sent to the San Diego Padres of the Pacific Coast League. He played four seasons with the Padres before retiring from baseball in 1956.