John Derek was an American actor, filmmaker and photographer. He appeared in such films as Knock on Any Door, All the King's Men, Rogues of Sherwood Forest (1950), and The Ten Commandments (1956). He was also known for launching the career of his fourth wife, Bo Derek.

Knock on Any Door is a 1949 American courtroom trial film noir directed by Nicholas Ray and starring Humphrey Bogart. The movie was based on the 1947 novel of the same name by Willard Motley. The picture gave actor John Derek his breakthrough role as young hoodlum Nick Romano, whose motto was, "live fast, die young, and have a good looking corpse."