John Joseph Mackinson (October 29, 1923 – October 17, 1989) was an American professional baseball pitcher who appeared in ten games (nine as a pitcher) in the major leagues (MLB) for the 1953 Philadelphia Athletics and 1955 St. Louis Cardinals. His pro career lasted 13 seasons (1946–1958). Mackinson returned to the minors in 1956 and played three more seasons. He died at age 65 in the Los Angeles suburb of Reseda on October 17, 1989.