William Anthony Jackowski (September 27, 1914 – July 29, 1996) was a professional baseball umpire who worked in the National League from 1952 to 1968. Jackowski umpired 2,517 major league games in his 17-year career. He umpired in three World Series (1958, 1960 and 1966) and three All-Star Games (1956, 1959 and 1963).