Andrus was born in Wilmington, New York to Ruluf Andress and Azuba Smith.
Andrus joined the LDS Church in 1832 in Florence, Ohio. He was one of the members of Zion's Camp. He helped build the Kirtland, Nauvoo, Salt Lake, and Saint George Temples. He served as a missionary in England in the early 1840s. He led three wagon trains of Mormon Pioneers from the Midwest to the Salt Lake Valley (1850, 1855, and 1861). He was a Bishop in Nauvoo, a Stake President in St. Louis, a member of the Quorum of the Seventy, and was serving as a Patriarch at his death.
While in St. Louis, Andrus preached many sermons. Among those who joined the Church due to his preaching was Carl Eyring, who would later serve many years as president of the Indian Territory Mission in Oklahoma, and who was the grandfather on the noted physicist Henry Eyring.
Andrus was a polygamist, and had 11 wives and 57 children.
Andrus was a major during the Utah War and was a chaplain of the Utah State Legislature. He built many roads in Utah and southern Idaho.
- Homer, William E. "Milo ANdrus" in Garr, Arnold K., Donald Q. Cannon and Richard O. Cowan, ed. Encyclopedia of Latter-day Saint History (Salt Lake City: Deseret Book COmpany, 2000) p. 27
- Barrett, Ivan J. (1992) Trumpeter of God: Fascinating True Stories of the Great Missionary and Colonizer, Milo Andrus. American Fork, Utah: Covenant Communications, Inc.
- Encyclopedia of Latter-day Saint Church History, p. 27