A cult following is a group of fans who are highly dedicated to a person, idea, object, movement, or work, often an artist, in particular a performing artist, or an artwork in some medium. The latter is often called a cult classic. A film, book, musical artist, television series, or video game, among other things, is said to have a cult following when it has a very passionate fanbase.

A common component of cult followings is the emotional attachment the fans have to the object of the cult following, often identifying themselves and other fans as members of a community. Cult followings are also commonly associated with niche markets. Cult media are often associated with underground culture, and are considered too eccentric or anti-establishment to be appreciated by the general public or to be widely commercially successful.

Many cult fans express their devotion with a level of irony when describing such entertainment. Fans may become involved in a subculture of fandom, either via conventions, online communities or through activities such as writing series-related fiction, costume creation, replica prop and model building, or creating their own audio or video productions from the formats and characters.

There is not always a clear difference between cult and mainstream media. Professors Xavier Mendik and Ernest Mathijs, authors of 100 Cult Films, argue that the devoted following among these films make them cult classics. In many cases, films that have cult followings may have been financial flops during their theatrical box office run, and even received mixed or mostly negative reviews by mainstream media, but are still considered a major success by small core groups or communities of fans.

Some cults are only popular within a certain subculture. The film Woodstock (1970) is especially loved within the hippie subculture, while Hocus Pocus (1993) holds cult status among American women born in the 1980s and early 1990s. Certain mainstream icons can become cult icons in a different context for certain people. Reefer Madness (1936) was originally intended to warn youth against the use of marijuana, but because of its ridiculous plot, overwhelming number of factual errors and cheap look, it became watched by audiences of marijuana smokers and has gained a cult following.

Quentin Tarantino's films borrow stylistically from classic cult films, but are appreciated by a large audience; therefore, Tarantino's filmography is noted worldwide as lying somewhere between cult and mainstream cinema. Also, certain cult phenomena can grow to such proportions that they become mainstream, such as the filmography of cult directors like John Waters, John Sayles, John Cassavetes, Armando Bó, Eliseo Subiela, Ruggero Deodato, Takeshi Kitano, Abbas Kiarostami or Jesús Franco.

Certain television series develop a cult following after their cancellation, which may cause interest in renewal. Arrested Development, which was cancelled in 2006 after its third season, was renewed by Netflix in 2013 and received two additional seasons. Futurama was cancelled in 2003 after its fourth season on Fox, but was later picked up by Comedy Central for an additional three seasons. In 2022, it was announced the series would be renewed for 20 additional episodes (released weekly) on the streaming service Hulu. Star Trek was cancelled after three seasons, but in broadcast syndication it gained a more substantial following, ultimately spawning a successful media franchise.

David Lynch's Twin Peaks ran on ABC for two seasons from 1990 to 1991, initially garnering high ratings and critical acclaim. Ratings and reception declined following ABC's demand that the show reveal the core mystery of Laura Palmer's murderer, the revelation of which was not ever intended to be revealed in the show by Lynch and co-creator Mark Frost. Eventually, the show was canceled, ending on a cliffhanger. It was not until 2017 that Twin Peaks returned as a limited series on Showtime, ending one of the longest hiatuses in television history.