An extra, also called a background actor, 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 extras in large numbers: some films have featured hundreds or even thousands of paid extras. Likewise grand opera can involve many extras appearing in spectacular productions.

On a movie set, film extras are technically referred to as "background action," "background performers" or, simply, "background." In a stage production, extras are commonly referred to as "supernumeraries." In television they are sometimes known as "supporting artistes" or "S.A.s". In opera and ballet they are called either 'extras' or 'supers'.