Megan Mullally (born November 12, 1958) is an American actress and singer.After working in theatre in Chicago, Mullally moved to Los Angeles in 1985 and began to appear in supporting roles in film and television productions. She made her Broadway debut in Grease in 1994 and has since appeared in several Broadway musicals. She is best known for playing the wealthy, alcoholic socialite Karen Walker on the Emmy Award-winning TV sitcom Will & Grace from 1998-2006.