John Thomas McIntyre (26 November 1871 – 21 May 1951) was an American playwright, and novelist of mystery and crime fiction.

Working for South Street Standard Theatre(stock company), he wrote a weekly play based on a set of posters produced for the theater's entrance.

In 1898, he started writing his first novel, a political drama set in the wards along the Schuylkill River and Philadelphia waterfront, The Ragged Edge. Published in 1902 by McClure Phillips, it is considered an early example of the urban Irish-American political novel.

However, McIntyre's successes as a serious novelist were limited and short-lived, and was forced to rely on writing short stories, detective mysteries and juvenile fiction to make a living.

He invented Ashton-Kirk, a scientific-minded criminologist, and published several books featuring his cases.

McIntyre's greatest success and fame came from his 1936 novel, Steps Going Down, which was selected as the United States entry in the All-Nations Prize Novel Competition.