Frank Samuel Knox (March 29, 1910 – May 1981) was an American football guard who played three seasons with the Detroit Lions of the National Football League. He first enrolled at the University of New Hampshire before transferring to the University of Illinois. He initially attended Concord High School in Concord, New Hampshire before transferring to Phillips Exeter Academy in Exeter, New Hampshire and lastly Clark Preparatory School in Hanover, New Hampshire.