Margaret JoBeth Williams (born December 6, 1948) is an American actress and television director. Her directorial debut with the 1994 short film On Hope earned her an Academy Award nomination for Best Live Action Short Film. Since 2009, she has served as president of the Screen Actors Guild Foundation.
Williams rose to prominence appearing in such films as Stir Crazy (1980), Poltergeist (1982), The Big Chill (1983), The Day After (1983), Teachers (1984), and Poltergeist II: The Other Side (1986).