Born in England, Marks spent time as a prizefighter before his film career began in 1928, when Warner Bros. contracted him as a film editor. He edited over 95 films during his tenure. He was nominated for the Academy Award for Best Film Editing for Casablanca (1942) and Janie (1944), but did not win either time.
Marks died on 18 September 1960, in Los Angeles, California. His final films as editor, The Sins of Rachel Cade and Parrish, were released posthumously in 1961.