Her stars an actress.
Her (film) . The film follows Theodore Twombly ( Joaquin Phoenix ) , a man who develops a relationship with Samantha ( Scarlett Johansson ) , an intelligent computer operating system personified through a female voice . Patricia Rooney Mara ( [ ˈmɛərə ] ; born April 17 , 1985 ) is an American actress and philanthropist . Scarlett Johansson ( [ dʒoʊˈhænsən ] born November 22 , 1984 ) is an American actress , model , and singer .