Halloween is a 1978 American independent slasher film directed, co-written, and scored by John Carpenter. Starring Donald Pleasence and Jamie Lee Curtis (in her film debut), with P. J. Soles and Nancy Loomis in supporting roles, the film is set mostly in the fictional town of Haddonfield, Illinois. The plot centers on a mental patient, Michael Myers, who was committed to a sanitarium for murdering his teenage sister on Halloween night when he was a child. Fifteen years later, having escaped and returned to his hometown, he stalks teenage babysitter Laurie Strode and her friends while under pursuit by his psychiatrist Dr. Samuel Loomis.

Filming took place in Southern California in May 1978. The film premiered in October and grossed $70 million, becoming one of the most profitable independent films of all time. Primarily praised for Carpenter's direction and score, many critics credit the film as the first in a long line of slasher films inspired by Alfred Hitchcock's Psycho (1960) and Bob Clark's Black Christmas (1974). It is considered one of the greatest and most influential horror films ever made. In 2006, it was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".Halloween spawned a film franchise comprising thirteen films which helped construct an extensive backstory for its antagonist Michael Myers, sometimes narratively diverging entirely from previous installments. Additionally, a novelization, a video game and comic book series have been based on the film.