Dennis Michael Quinn (born March 26, 1944) is an American historian who has focused on the history of the Church of Jesus Christ of Latter-day Saints (LDS Church).
He was a professor at Brigham Young University (BYU) from 1976 until he resigned in 1988.
At the time, his work concerned church involvement with plural marriage after the 1890 Manifesto, when new polygamous marriages were officially prohibited.
He was excommunicated from the church as one of the September Six and is now openly gay.