A cult film or cult movie, also commonly referred to as a cult classic, is a film that has acquired a cult following. Cult films are known for their dedicated, passionate fanbase which forms an elaborate subculture, members of which engage in repeated viewings, dialogue-quoting, and audience participation. Inclusive definitions allow for major studio productions, especially box-office bombs, while exclusive definitions focus more on obscure, transgressive films shunned by the mainstream. The difficulty in defining the term and subjectivity of what qualifies as a cult film mirror classificatory disputes about art. The term cult film itself was first used in the 1970s to describe the culture that surrounded underground films and midnight movies, though cult was in common use in film analysis for decades prior to that.

The term midnight movie is rooted in the practice that emerged in the 1950s of local television stations around the United States airing low-budget genre films as late-night programming, often with a host delivering ironic asides. As a cinematic phenomenon, the midnight screening of offbeat movies began in the early 1970s in a few urban centers, particularly in New York City with screenings of El Topo at the Elgin Theater, eventually spreading across the country. The screening of non-mainstream pictures at midnight was aimed at building a cult film audience, encouraging repeat viewing and social interaction in what was originally a countercultural setting.