Susan Diane Ruttan (née Dunsrud; born September 16, 1948) is an American actress.

She earned four nominations for Primetime Emmy Award for Outstanding Supporting Actress in a Drama Series for her performance in show.

Other television appearances included episodes of Buffy the Vampire Slayer, AfterMash, Bosom Buddies, 3rd Rock from the Sun, Remington Steele, Yes, Dear, Newhart and Gilmore Girls.

Buffy creator Joss Whedon cast numerous show alumni in 2008's Dr. Horrible's Sing-Along Blog, including Ruttan who appeared briefly in a non-speaking role.

Her most dramatic role to date was in the 2004 remake of Helter Skelter, in which she played the mother of Linda Kasabian.