Unhinged is a 1982 American slasher film directed by Don Gronquist, written by Gronquist and Reagan Ramsey, and starring Laurel Munson, Janet Penner, and Sara Ansley. The film follows three young women who, after suffering a car accident, are taken in by a mysterious family at their rural Pacific Northwest mansion, where they are subsequently stalked by a violent murderer.

The screenplay for Unhinged was completed by Gronquist and Ramsey in September 1977, when it was registered for U.S. copyright. Principal photography took place in 1981 in Gronquist's hometown of Portland, Oregon on a budget of $100,000. Filming primarily took place at the Pittock Mansion, whose interiors were used over a course of 19 nights due to the estate's daily operation as a museum. Additional photography took place in St. Johns and Forest Park, with Gus Van Sant serving as a location scout for the production.

Unhinged screened at the Cannes Film Festival's Marché du Film in May 1983, and was released on video shortly after in the United Kingdom by CBS/Fox. It subsequently appeared on the list of the United Kingdom's 72 "video nasties," which led to an expanded role for the British Board of Film Classification (BBFC). Video copies of the film were seized and confiscated by the British government during police raids in December 1983. Despite censorship efforts for its home video release, the film received an 18 certificate from the BBFC for theatrical release, and screened throughout the United Kingdom in the latter half of 1983. In the United States, it opened at the Northwest Film & Video Festival in Portland on August 20, 1983.

Though the film received little critical attention at the time of its release, it has been subject to retrospective reviews and reassessment, receiving praise for its atmosphere, synthesizer-based musical score, and twist ending, and criticism for its acting and pacing. In 2014, the film's original score by Jonathan Newton was ranked at number 40 in a list of the 100 greatest horror film scores by Fact magazine. The film has also been the topic of scholarly discussion due to its depiction of repression and gender dysphoria of its villain, and has also drawn comparisons to Alfred Hitchcock's Psycho (1960). A remake was made in England and released in 2017.