The Black Sleep (American reissue title Dr. Cadman's Secret) is a 1956 American independent horror film produced by Bel Air Productions, directed by Reginald LeBorg, and written by John C. Higgins from a story by Gerald Drayson Adams. It stars Basil Rathbone, Lon Chaney Jr., John Carradine, Bela Lugosi, and Akim Tamiroff. Tor Johnson appears in a supporting role.