A gangster film or gangster movie is a film belonging to a genre that focuses on gangs and organized crime. It is a subgenre of crime film, that may involve large criminal organizations, or small gangs formed to perform a certain illegal act. The genre is differentiated from Westerns and the gangs of that genre.

Crime films, in the broadest sense, is a film genre inspired by and analogous to the crime fiction literary genre. Films of this genre generally involve various aspects of crime and its detection. Stylistically, the genre may overlap and combine with many other genres, such as drama or gangster film, but also include comedy, and, in turn, is divided into many sub-genres, such as mystery, suspense or noir.