Night of the Demon (U.S. title: Curse of the Demon) is a 1957 British horror film directed by Jacques Tourneur and starring Dana Andrews, Peggy Cummins and Niall MacGinnis. It was produced by Hal E. Chester and Frank Bevis, and was adapted from the M. R. James story "Casting the Runes". The film's storyline concerns an American psychologist (Andrews) who travels to England to investigate a satanic cult suspected in more than one death.

Turbulent artistic differences arose between producer Hal E. Chester on one side, and director Tourneur and writer Charles Bennett on the other over Chester's plan to show the demon on screen, but Chester prevailed. To accelerate the pace and make the film more commercial, the 96-minute original feature was trimmed down to 82 minutes prior to its release in the United States. This shortened version was retitled Curse of the Demon, playing in June 1958 as the second half of a double feature with either The True Story of Lynn Stuart (1958) or The Revenge of Frankenstein (1958), depending on the local film market.

Though not a significant commercial success on its initial release in 1957, Night of the Demon has been highly acclaimed by critics and filmmakers in retrospect, and is considered one of the greatest horror films of all time. At the film review aggregator website Rotten Tomatoes, the film holds an approval rating of 100%.