Member of the Phi Gamma Delta fraternity.
On an episode of "8 Simple Rules" (2002), he and the cast did a spoof of his classic TV Series, "Three's Company" (1976). In the spoof, he played Mr. Roper, Katey Sagal played Helen Roper, Kaley Cuoco and Amy Davidson played Janet and Chrissy respectively, Billy Aaron Brown played Jack and Martin Spanjers played Larry. At the end of the episode, Don Knotts who played Mr. Furley in "Three's Company," reprised his role in one short scene. It was, not surprisingly, Ritter's favorite episode.
One of John's last public appearances was at Disney's Prime Time Weekend at Disney's California Adventure Park, 4 days before his death.
Paul Hennessy, Ritter's character on "8 Simple Rules" (2002), was ranked #48 in TV Guide's list of the "50 Greatest TV Dads of All Time" [20 June 2004 issue].
Starred with his wife, Amy Yasbeck, in an episode of "The Cosby Show" (1984) 8 years prior to their marriage. Coincidently, they played a husband and wife expecting their first child.
Was considered for the role of Dan Gallagher in Fatal Attraction (1987).
Was nominated for an Emmy, for best actor in a comedy, for "8 Simple Rules" one year after his death, after only appearing in 3 episodes.
Was the first guest of "The Wayne Brady Show" (2002).