Daniel Hanmer Wells was born October 27, 1814 in Trenton, New York the son of Daniel Wells and Catherine Chapin. During Wells’ youth he received a sound education due to his families’ prosperous financial situation, his father having served numerous terms as governor of Connecticut. In 1826 Wells’ father died unexpectedly and the family moved to a remote village later known as Commerce, Illinois. During the 1830s Wells was elected constable and later justice of the peace of Commerce.

In 1839 when members of the Church of Jesus Christ of Latter-day Saints began settling in Commerce after fleeing from Missouri, Wells sold his personal land at a discounted price to the more financially destitute Latter-day Saints refugees. Shortly thereafter Joseph Smith, the leader and founder of the LDS Church, became personally acquainted with and strongly attached to Wells even though Wells was not a member of the LDS faith. This relationship later lent support to Wells’ successful election to city alderman and city councilman of Nauvoo, Illinois, the city that served as the LDS Church's headquarters during the early 1840s. Wells was also selected as a regent of the University of Nauvoo and sustained as a brigadier-general of the Nauvoo Legion.

After the murder of Joseph Smith in June 1844 and an expulsion order was issued against the Latter-day Saint population of Nauvoo, Wells made the decision to join the LDS Church and was baptized in 1846. As a brigadier-general of the Nauvoo Legion, Wells oversaw and participated in the Battle of Nauvoo. From 1846 to 1847 Wells remained in the Nauvoo area attempting to negotiate financial compensation on behalf of exiled Latter-day Saints.

In 1848 Wells arrived in the Utah Territory and began working toward the organization of the State of Deseret. He was elected to the first legislative council, appointed state attorney, and was elected major-general of the Utah Territory based Nauvoo Legion in 1849 (in 1852 he was promoted to lieutenant-general). In 1857, as lieutenant-general of the Legion, Wells personally participated in the LDS Church's campaign against local Native American Indians. During Utah War Wells commanded the Legion and directed military affairs and organized preparations surrounding the arrival of Johnston's Army.

On January 4, 1857 Wells was sustained as Brigham Young's second councilor, the third highest position in the LDS Church. In 1864 Wells was sent to Great Britain to preside over the LDS Church's European missions, where he remained for one year. In 1866 Wells returned to the Utah Territory and was elected mayor of Salt Lake City, a position he held until 1874.

In 1871 Wells was arrested for being an accessory in the murder of Robert Yates, a murder that occurred in 1857 at the mouth of Echo Canyon. Bill Hickman eventually confessed to killing Yates, but Wells was the official commanding officer of the military operation which resulted in the death of Yates. However, after a year of deliberation charges were dismissed.

From 1868 to 1884 Wells presided and worked in the Salt Lake City Endowment House, administering LDS ordinances and performing plural marriages. In 1879 he was jailed for failing to disclose information regarding the various polygamist marriages he had performed. He spent a few months in jail and paid a $100 fine before being released.

From 1884 to 1887 Wells lived in Europe to oversee the labors of the LDS Church's missionary program. During this time he resided in Great Britain, but also visited Germany, Switzerland, France, and the Scandinavian countries. In 1888 he returned to Utah and was made president of the Manti Temple, a position he held until his death. Wells died in Salt Lake City on March 27, 1891.