Leading lady
Leading lady is a term often applied to the leading actress in the performance if her character is the protagonist. It is also an informal term for the actress who plays a secondary lead, usually a love interest, to the leading actor in a film or play.
A leading lady can also be an actress of renown. For example, Lynn Fontanne and Helen Hayes were both referred to as the "leading lady of the theatre" in their time. Similarly, Mary Pickford was called the "leading lady" of the cinema.
The term has been applied to an actress who is often associated with one particular actor. For example, Olivia de Havilland was Errol Flynn's leading lady in several films, Katharine Hepburn had a similar association with Spencer Tracy, Lauren Bacall with Humphrey Bogart, and Maureen O'Hara with John Wayne. A leading lady is also an actress who is typecast in romantic supporting roles.
The term can also be used collectively; for example, the phrase "Hollywood's leading ladies" can be used to refer to a group of notable, famous, or popular actresses.