American religious leader, sixth president (1901–18) of the Church of Jesus Christ of Latter-day Saints (the main Mormon denomination).

After his uncle Joseph Smith, the founder of Mormonism, and his father, Hyrum Smith, were murdered in Carthage, Ill., in 1844, he and his mother fled with the majority of the Mormons to Utah. Made an apostle of the church in 1866, Smith advanced within the hierarchy to the office of president in 1901. He also served on the city council of Salt Lake City and in the territorial legislature (1865–74, 1880, 1882). Smith had six wives, but he accepted the decision to give up polygamy reached by church leaders in 1890 and testified before a United States Senate committee that Mormons no longer accepted the practice.