An art film (or arthouse film) is typically an independent film, aimed at a niche market rather than a mass market audience. It is "intended to be a serious, artistic work, often experimental and not designed for mass appeal", "made primarily for aesthetic reasons rather than commercial profit", containing "unconventional or highly symbolic content".

Film critics and film studies scholars typically define an art film as possessing "formal qualities that mark them as different from mainstream Hollywood films". These qualities can include (among other elements): a sense of social realism; an emphasis on the authorial expressiveness of the director; and a focus on the thoughts, dreams, or motivations of characters, as opposed to the unfolding of a clear, goal-driven story. Film scholar David Bordwell describes art cinema as "a film genre, with its own distinct conventions".

Art film producers usually present their films at special theaters (repertory cinemas or, in the U.S., art-house cinemas) and at film festivals. The term art film is much more widely used in North America, the United Kingdom, and Australia, compared to mainland Europe, where the terms auteur films and national cinema (e.g. German national cinema) are used instead. Since they are aimed at small, niche-market audiences, art films rarely acquire the financial backing that would permit large production budgets associated with widely released blockbuster films. Art film directors make up for these constraints by creating a different type of film, one that typically uses lesser-known film actors (or even amateur actors), and modest sets to make films that focus much more on developing ideas, exploring new narrative techniques, and attempting new film-making conventions.

Such films contrast sharply with mainstream blockbuster films, which are usually geared more towards linear storytelling and mainstream entertainment. Film critic Roger Ebert called Chungking Express, a critically acclaimed 1994 art film, "largely a cerebral experience" that one enjoys "because of what you know about film". That said, some art films may widen their appeal by offering certain elements of more familiar genres such as documentary or biography. For promotion, art films rely on the publicity generated from film critics' reviews; discussion of the film by arts columnists, commentators, and bloggers; and word-of-mouth promotion by audience members. Since art films have small initial investment costs, they only need to appeal to a small portion of mainstream audiences to become financially viable.