Leonard James Arrington (July 2, 1917 – February 11, 1999) was an American author, academic and the founder of the Mormon History Association. He is known as the "Dean of Mormon History" and "the Father of Mormon History" because of his many influential contributions to the field. Since 1842, he was the first non-general authority Church Historian for the Church of Jesus Christ of Latter-day Saints (LDS Church), from 1972 to 1982, and was director of the Joseph Fielding Smith Institute for Church History from 1982 until 1986.