Patricia Rooney Mara /ˈmɛərə/ MAIR-ə is an American actress and philanthropist. She made her screen debut in the slasher film Urban Legends: Bloody Mary and went on to have a breakout role in the independent coming-of-age drama Tanner Hall, followed by roles in the 2010 remake of A Nightmare on Elm Street and the biographical drama film The Social Network.