Black Christmas is a 1974 Canadian slasher film directed by Bob Clark and written by A. Roy Moore, and largely based on a series of murders that took place in Quebec, Canada around Christmas time. It was distributed by Ambassador Film Distributors in Canada and Warner Bros. in the United States. It follows a group of college students who must face a deranged serial killer lurking in their sorority house. It stars Olivia Hussey, Keir Dullea, Margot Kidder, Andrea Martin, Marian Waldman, and John Saxon.