John T. Dugan (October 11, 1920 – December 24, 1994) was an American screenwriter. He wrote for television programs, including Bonanza, Mr. Novak, 12 O'Clock High, Dr. Kildare, Adam-12, Star Trek: The Original Series, Ben Casey, Mission: Impossible, Columbo and Little House on the Prairie. Dugan died in December 1994 of pancreatic cancer at his home in Encino, California, at the age of 74.^[2]

Dugan was twice nominated for the Writers Guild of America Award for Television: Episodic Drama: in 1968, for the Star Trek: The Original Series episode "Return to Tomorrow"; and in 1980, for the Little House on the Prairie episode "Second Spring".^{[citation needed]}