The Latter Day Saint movement (also called the LDS movement, LDS restorationist movement, or SmithRigdon movement) is the collection of independent church groups that trace their origins to a Christian Restorationist movement founded by Joseph Smith in the late 1820s.

Collectively, these churches have over 16 million members, although about 98% belong to The Church of Jesus Christ of Latter-day Saints (LDS Church). The predominant theology of the churches in the movement is Mormonism, which sees itself as restoring the early Christian church with additional revelations.

A minority of Latter Day Saint adherents, such as members of Community of Christ, have been influenced by Protestant theology while maintaining certain distinctive beliefs and practices including continuing revelation, an open canon of scripture and building temples. Other groups include the Remnant Church of Jesus Christ of Latter Day Saints, which supports lineal succession of leadership from Smith's descendants, and the more controversial Fundamentalist Church of Jesus Christ of Latter-Day Saints, which defends the practice of polygamy.

The Church of Christ was the original name of the Latter Day Saint church founded by Joseph Smith. Organized informally in 1829 in New York and then formally on April 6, 1830, it was the first organization to implement the principles found in Smith's newly published Book of Mormon, and thus its establishment represents the formal beginning of the Latter Day Saint movement. Later names for this organization included the Church of the Latter Day Saints (by 1834 resolution), the Church of Jesus Christ, the Church of God, the Church of Christ of Latter Day Saints, and the Church of Jesus Christ of Latter Day Saints (by an 1838 revelation).Smith and his associates asserted that the Church of Christ was a restoration of the 1st-century Christian church, which Smith claimed had fallen from God's favor and authority because of what he called a "Great Apostasy". After Smith's death in 1844, there was a crisis of authority, with the majority of the members following Brigham Young to the Salt Lake Valley, but with several smaller denominations remaining in Illinois or settling in Missouri and in other states. Each of the churches that resulted from this schism considers itself to be the rightful continuation of Smith's original "Church of Christ", regardless of the name they may currently bear (The Church of Jesus Christ of Latter-day Saints (LDS Church), Community of Christ, The Church of Jesus Christ (Bickertonite), Church of Christ (Temple Lot), etc.).

This church is unrelated to other bodies bearing the same name, including the United Church of Christ, a Reformed church body, and the Churches of Christ, an offshoot of the Campbellite movement. Today, there are several Latter Day Saint churches called "Church of Christ", largely within the Hedrickite branch of the movement.