A supporting actor or supporting actress is an actor who performs a role in a theatre play or movie below that of the leading actor(s), and above that of a bit part.

Supporting actors are often important to the plot as a best friend, lover, sidekick (such as Robin in the Batman series), or antagonist (such as the villain). They are sometimes, but not necessarily, character roles.

In television series, the term day player is used to refer to actors with supporting roles, who may appear short-term or long-term.

In recognition of the important nature of this work, the theatre and movie industries give separate awards to the best supporting actors and actresses (for example: Academy Award for Best Supporting Actor and Academy Award for Best Supporting Actress).

• Title role
• Leading actor
• Character actor
• Bit part
• Extra (acting)