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 "" (1986). A three-time Emmy Award nominee, she was nominated for Outstanding Lead Actress in a Miniseries or a Movie for her work in the TV movie "Adam" (1983) and the TV miniseries "Baby M" (1988). Her third nomination was for her guest role in the sitcom "Frasier" (1993–94). She also starred in the TV series "The Client" (1995–96) and had recurring roles in the TV series "Dexter" (2007) and "Private Practice" (2009–11).