Williams played William Shakespeare in "The Twilight Zone" episode "The Bard" (1963) and guest-starred on the sitcom "My Three Sons" (also 1963), portraying a stuffy, very precise English butler. In the latter role he was clean shaven, not sporting his customary mustache. Later, he was briefly part of the regular cast of the family comedy "Family Affair" (1967). He appeared as well on "Night Gallery" in the series' episode "The Doll" (1971). One of Williams' last performances was in 1979, playing alongside fellow actor Lorne Greene in a two-part episode of "Battlestar Galactica" titled "War of the Gods".