The first religions of Arizona were the sacred beliefs and practices of the Indians. Catholic missionaries began converting Arizona Indians (Franciscans among the Hopi, and Jesuits among the Pima) to the Christian faith in the late 17th century. By the late 18th century, the Franciscans were the main missionary force, and the Roman Catholic Church was firmly established. In 2000, the state had 974,883 Catholics in 267 congregations.

The Church of Jesus Christ of Latter-day Saints (Mormons) constitutes the 2nd-largest Christian denomination with 251,974 adherents in 643 congregations. Mormons were among the state's earliest Anglo settlers. Other major Christian denominations include the Southern Baptist Convention, 138,516 adherents; Assemblies of God, 82,802; and the United Methodist Church, 53,232.

In 2000, Arizona's estimated Jewish population was 81,675. There were about 11,857 Muslims. There were also about 25 Buddhist and 9 Hindu congregations.