His father, cowboy star Tex Ritter, tried to steer him away from an acting career but lived long enough to rejoice in seeing him in a recurring role on "The Waltons" (1971), which was Tex's favorite TV program.
His talent for physical schtick was heralded by TV's top comedy icon Lucille Ball, who hosted a tribute to John's talent on "Three's Company" (1976). John later appeared in an episode of Lucille's last comedy series "Life with Lucy" (1986) In that episode, Lucy claims that during the shooting of a scene, it was the third time in her entire career that she had to yell "cut" because he broke her up laughing.
Best remembered by the public for his starring role as Jack Tripper on "Three's Company" (1976).
Ended 20 year rift with his "Three's Company" (1976) co-star Suzanne Somers shortly before his death.
In "Three's Company" (1976) and "Three's a Crowd" (1984), he played a straight man pretending to be gay. In Perceptions (2005), his son, Jason Ritter, played a gay man pretending to be straight.
His favorite musical group was The Beatles, and he even appeared on Ringo Starr's TV special Ringo (1978) (TV).
Father of 4 children: Jason Ritter, (born on Sunday, February 17th, 1980), Carly Ritter, (born on Monday, March 1, 1982), Tyler Ritter, (born on Thursday, January 31st, 1985) and Stella Ritter, (born on Friday, September 11th, 1998).
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.
During an interview on "Late Night with Conan O'Brien" (1993), Ritter claimed that he chose the name "Vaughan Cunningham" for his character in Sling Blade (1996) based on an in-joke with the cast of "Happy Days" (1974).
Married Amy Yasbeck in Wilmington, Ohio. The two had lived together for a couple of years. [18 September 1999]
Was the first guest of "The Wayne Brady Show" (2002).
Paul Hennessy, Ritter's character on "8 Simple Rules... for Dating My Teenage Daughter" (2002), was ranked #48 in TV Guide's list of the "50 Greatest TV Dads of All Time" [20 June 2004 issue].
On an episode of "8 Simple Rules... for Dating My Teenage Daughter" (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.
Biography in: "The Scribner Encyclopedia of American Lives". Volume 7, 2003-2005, pages 464-465. Farmington Hills, MI: Thomson Gale, 2007.
His final film, Bad Santa (2003), was dedicated to his memory.
Buried at Forest Lawn Hollywood Hills, 6300 Forest Lawn Drive, Los Angeles, California (actually borders Glendale and Griffith Park). Lot 1622 Court of Liberty near Stan Laurel's grave-site.