costarring

Costarring is the practice of acting in a film, television series, or stage production in which two or more actors share prominent screen or stage time. A costar is a principal performer whose role is on roughly equal terms with one or more other leads, rather than a mere supporting character. Costarring can occur when two leads share top billing, or when a production builds an ensemble around several central characters.

In film and television, costars are typically credited near the top of the cast and may appear together in publicity materials. The term is distinct from lead roles, which are the main focus of the story, and from supporting roles, which are secondary or peripheral. In theatre, costarring can describe two actors who share central stage time across scenes, though billing practices differ from media to media.

Billing and screen time influence how costars negotiate contracts and residuals, and casting decisions may aim to balance star power, chemistry, and audience appeal. The exact definition of who qualifies as a costar can vary by project, country, and union jurisdiction; some productions label a performer as a co-star even when their part is technically secondary.

Costarring is usually used as a descriptive term in press materials and credits. The form can be written as costarring, co-starring, or costar as a noun, and both co-star and costar are common spellings. The term emphasizes collaboration between performers who contribute significantly to the production’s central narrative.