A background actor or extra is a performer in a film, television show, stage, musical, opera or ballet production, who appears in a nonspeaking, nonsinging or nondancing capacity, usually in the background (for example, in an audience or busy street scene). War films and epic films often employ background actors in large numbers: some films have featured hundreds or even thousands of paid background actors. Likewise, grand opera can involve many background actors appearing in spectacular productions.

On a film or TV set, background actors are usually referred to as "background performers", "background artists" or simply "background" while the term "extra" is rarely used. In a stage production, background actors are commonly referred to as "supernumeraries". In opera and ballet, they are called either "extras" or "supers".