[American horror franchise that consists of twelve slasher films, a television show, novels, comic books, and tie-in merchandise. The franchise mainly focuses on the fictional character of Jason Voorhees, who drowned at Camp Crystal Lake as a boy due to the negligence of the camp staff. Decades later, the lake is rumored to be "cursed" and is the setting for a series of mass murders. Jason is featured in all of the films, either as the killer or the motivation for the killings. The original film was written by Victor Miller, and was produced and directed by Sean S. Cunningham; neither returned to write or direct any of the sequels.

The first film was created to cash in on the success of Halloween (1978), and its own success led Paramount Pictures to purchase the full licensing rights to the Friday the 13th franchise. Frank Mancuso, Jr., who produced the films, also developed the television show Friday the 13th: The Series after Paramount released Jason Lives. The television series was not connected to the franchise by any character or setting, but was created based on the idea of "bad luck and curses", which the film series symbolized.Grove, David, pp. 189–196 While the franchise was owned by Paramount, four films were adapted into novels, with Friday the 13th Part III adapted by two separate authors. When the franchise was sold to New Line Cinema, Cunningham returned as a producer to oversee two additional films, as well as the crossover film with Freddy Krueger from the Nightmare on Elm Street film series. Under New Line, thirteen novellas and various comic book series were published featuring Jason.