Mary Steenburgen is an American actress and singer who is best known for her roles in films such as Back to the Future Part III, Parenthood, The Proposal, Step Brothers, and Book Club. She has won an Academy Award for her performance in Melvin and Howard and has been nominated for two Golden Globe Awards. She is a versatile performer who has starred in both comedic and dramatic roles. She has a natural charm and charisma that brings life to her characters. Her performances are always memorable and entertaining.