Mormonism is a religion, belief system, and culture originating with Joseph Smith, Jr in the early 1800s. Mormons refer to their religion as a form of Christianity, although many of their beliefs are considered unorthodox by Catholics, Protestants, and other Christians. Many who practice Mormonism call themselves Mormons or Latter-day Saints.

There are numerous religious organizations who practice Mormonism, but by far the largest and most recognized organization is the Church of Jesus Christ of Latter-day Saints. Other notable organizations include the Community of Christ and the Church of Jesus Christ of Latter Day Saints (Strangite). There are also numerous small fundamentalist Mormon organizations throughout Utah, Idaho, Arizona, and surrounding states who practice polygamy; however, these groups, and the practice of polygamy, are rejected by most Mormons.