Friday the 13th is a 1980 American slasher film produced and directed by Sean S. Cunningham, written by Victor Miller, and starring Betsy Palmer, Adrienne King, Harry Crosby, Laurie Bartram, Mark Nelson, Jeannine Taylor, Robbi Morgan, and Kevin Bacon. Its plot follows a group of teenage camp counselors who are murdered one by one by an unknown killer while attempting to re-open an abandoned summer camp.

Prompted by the success of John Carpenter's Halloween (1978), director Cunningham put out an advertisement to sell the film in Variety in early 1979, while Miller was still drafting the screenplay. After casting the film in New York City, filming took place in New Jersey in the summer of 1979, on an estimated budget of $550,000. A bidding war ensued over the finished film, ending with Paramount Pictures acquiring the film for domestic distribution, while Warner Bros. Pictures secured European distribution rights.

Released on May 9, 1980, Friday the 13th was a major box office success, grossing $59.8 million worldwide. Critical response was divided, with some praising the film's cinematography, score, and performances, while numerous others derided it for its depiction of graphic violence. Aside from being the first independent film of its kind to secure distribution in the U.S. by a major studio, its box office success led to a long series of sequels, a crossover with the A Nightmare on Elm Street film series, and a 2009 series reboot. A direct sequel, Friday the 13th Part 2, was released one year later.