Thomas Edgar "Ed" Lyon (9 August 1903 – 20 September 1978) was a prominent Latter-day Saint historian and educator. He is most noted for his work on 19th century Latter-day Saint history. He also wrote on Latter-day Saint doctrine. Lyon was born in Salt Lake City, Utah. At age nine he began working in his father's print shop and at age 12 he began to spend summers doing ranch work in Jackson Hole, Wyoming. Lyon then served for a short time as a professor at Ricks College. In November 1933 he took over as president of the Netherlands Mission of the LDS Church from Frank I. Kooyman.