Norman John Warren was an English film director best known for such 1970s horror films as Satan's Slave (1976), Prey (1977) and Terror (1978). Warren is also known for sex comedies such as Outer Touch.

Satan's Slave is a 1976 British supernatural horror film directed by Norman J. Warren, written by David McGillivray, and starring Candace Glendenning, Michael Gough, Martin Potter, and Barbara Kellerman. Its plot follows a young woman who, after surviving a car accident that kills her parents, stays in the remote estate of her uncle and cousin, unaware that they are both necromancers who intend to sacrifice her to resurrect the spirit of a supernaturally-gifted ancestor.