Jacob Nelson Fox (December 25, 1927 – December 1, 1975) was an American professional baseball player. He played in Major League Baseball (MLB) as a second baseman on three teams, primarily the Chicago White Sox, for 19 seasons, from 1947 through 1965. He was the American League (AL) Most Valuable Player (MVP) in 1959 and played in 12 MLB All-Star games. Fox was inducted into the National Baseball Hall of Fame in 1997.
Fox was born in St. Thomas Township, Pennsylvania. He began his career with the Philadelphia Athletics in 1947, though he was never a full-time starter during his three seasons with the team. Fox was a member of the 1949 Philadelphia Athletics team that set a major league team record of 217 double plays, a record which still stood as of 2010. He appeared in 77 games that season and contributed to 68 of the team's record number of double plays. Traded to the White Sox October 29, 1949, Fox's career took off. He spent 14 seasons with Chicago, making 10 All-Star teams. He played his final two seasons (1964–65) with the Houston Colt .45s and Astros.