noun
Refers to the main performer in a film, play, or show. Often used in credits or promotional materials.
彼女はその映画の主演者に選ばれた。
She was chosen as the star of that movie.
主演者の名前がポスターに大きく書かれている。
The leading actor's name is written in large letters on the poster.
主役 is a more general term for the leading role or protagonist, not necessarily limited to acting (e.g., in a story or event). 主演者 is specifically the leading actor in a performance.
Compound of 主演 (starring, leading role) and 者 (person).