Basket Case is a 1982 American horror film written and directed by Frank Henenlotter in his feature directorial debut. Produced by Edgar Ievins, the film stars Kevin Van Hentenryck as Duane Bradley, a young man who seeks vengeance on the doctors and nurses who performed an unwanted surgery that separated him from his deformed coned twin brother Belial, whom Duane hides in a large wicker basket.

Basket Case was shot on a "-16" camera on 16 mm in New York City, on a budget of around $35,000. The film was blown up to 35 mm for its original theatrical release in April 1982. Receiving mixed reviews upon release, it has since become considered a cult film, and has spawned two sequels, Basket Case 2 (1990) and Basket Case 3: The Progeny (1991), both of which were also directed by Henenlotter.

In 2017, Basket Case was selected for preservation by the Museum of Modern Art (MoMA), which oversaw a restoration of the film from its original 16 mm camera negative. The 4K restoration was released on Blu-ray and DVD by Arrow Video in 2018.