Johnathan Southworth "John" Ritter (September 17, 1948 - September 11, 2003) was an American actor and comedian, who is the son of country singer and actor Tex Ritter and the father of actor Jason Ritter. He was best known for his television roles as Jack Tripper on the ABC sitcom Three's Company from 1977 to 1984 and as Paul Hennessy on the ABC sitcom 8 Simple Rules for Dating My Teenage Daughter from 2002 until his death the following year during production in 2003. He is also best known for his voice role as the title protagonist on the animated children's series Clifford the Big Red Dog from 2000 to 2003. He appeared in the horror mini series IT, as the adult of Ben Hanscom.

His Disney roles were in the 1971 film The Barefoot Executive (his film debut) and the Playhouse Disney film Stanley's Dinosaur Round-Up. It was his final film and it was dedicated to his memory. He also appeared on some television specials in the 1980s, including guest-starring on Donald Duck's 50th Birthday in 1984 and hosting Disney's Living Seas in 1986. He also played Bob Chipeska in Bad Santa.