Prince of Darkness is a 1987 American horror film directed, written and scored by John Carpenter, starring Donald Pleasence, Victor Wong and Jameson Parker.

The story is set in a Los Angeles church, Father Loomis (Pleasence) invites Professor Howard Birack (Wong) and his students to investigate a mysterious cylinder in the basement of the building.

This film was the first to break Carpenter's run of low-budget commercial successes. Critically the film was poorly received, accused of being dull with an over-complicated plot, wordy script, wooden acting and uneven pacing, while offering insufficient 'horror' for Carpenter fans. It did poorly at the box-office, taking under $3 million in its first month from release, and has defied attempts to redefine it as a cult film. It was the first of a three film deal Carpenter had with Universal, it was followed by They Live (1988) and Memoirs of an Invisible Man (1992).

Carpenter's inventive skills in editing and mood-setting music are clearly demonstrated in the first half of the film before it loops through the standard horror trajectory. The film was shot through a slightly anamorphic lens, giving a subtle distortion to every scene. An eerie and fragmented foreshadowing dream sequence occurs repeatedly during the film, each time showing a little more and also providing a final twist.

Although Carpenter wrote the screenplay in the film's credits the writer is listed as Martin Quatermass, a homage repeated in the film with Kneale University.

The film features a cameo by Alice Cooper, playing a murderous vagrant who kills one of the hapless students with a bicycle frame.