Mob films — or gangster films — are a subgenre of American crime films dealing with organized crime, often specifically with the Mafia. Especially in early mob films, there considerable overlap with film noir.

The American movie The Black Hand (1906) is thought to be the earliest surviving gangster film. Though mob films had their roots in such silent films, the genre in its most durable form was defined in the early 1930s. It owed its innovations to the instability which resulted from the Great Depression, which catalyzed the gangster scene. The failure of honest hard work and careful investment to ensure financial security led to the explosion of mob films on to the Hollywood scene, and their immense popularity reflected a society disillusioned with the American way of life.

The years 1931 and 1932 saw the genre produce three enduring classics: Warner Bros.' Little Caesar and The Public Enemy, which made screen icons out of Edward G. Robinson and James Cagney, and Howard Hawks' Scarface starring Paul Muni, which offered a dark psychological analysis of a fictionalized Al Capone and launched the film career of George Raft. These films chronicle the quick rise, and equally quick downfall, of three young, violent criminals, and represent the genre in its purest form before moral pressure would force it to change and evolve. Though the gangster in each film would face a violent downfall which was designed to remind the viewers of the consequences of crime, audiences were often able to identify with the charismatic anti-hero. Those suffering from the Depression were able to relate to the gangster character who worked hard to earn his place and success in the world, only to have it all taken away from him.

Mob may refer to:

A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects. The process of filmmaking has developed into an art form and industry.

Films are cultural artifacts created by specific cultures, which reflect those cultures, and, in turn, affect them. Film is considered to be an important art form, a source of popular entertainment and a powerful method for educating – or indoctrinating – citizens. The visual elements of cinema give motion pictures a universal power of communication. Some films have become popular worldwide attractions by using dubbing or subtitles that translate the dialogue into the language of the viewer.

Films are made up of a series of individual images called frames. When these images are shown rapidly in succession, a viewer has the illusion that motion is occurring. The viewer cannot see the flickering between frames due to an effect known as persistence of vision, whereby the eye retains a visual image for a fraction of a second after the source has been removed. Viewers perceive motion due to a psychological effect called beta movement.