noun
title role
Refers to the character in a film, play, or other production whose name appears in the title, e.g., Hamlet in 'Hamlet'.
彼はその映画でタイトルロールを演じた。
He played the title role in that movie.
Variant with interpunct; less common in running text.
主役 is the lead role or protagonist, which may or may not be the title role. タイトルロール specifically means the character named in the title.
Borrowed from English 'title role'.