Dinah Beth Manoff (born January 25, 1958) is an American stage, film and television actress and television director best known for her roles as Elaine Lefkowitz on Soap, Marty Maraschino in the film Grease, Libby Tucker in both the stage and film adaptations of I Ought to Be in Pictures, for which she won a Tony award, and Carol Weston on Empty Nest.