The Church of Jesus Christ of Latter-day Saints, often informally known as the LDS Church or Mormon Church, is a nontrinitarian, Christian church that considers itself to be the restoration of the original church founded by Jesus Christ. The church is headquartered in the United States in Salt Lake City, Utah, and has established congregations and built temples worldwide. According to the church, it has over 16.8 million members and 54,539 full-time volunteer missionaries. The church is the fourth-largest Christian denomination in the United States, with over 6.7 million US members as of 2021. It is the largest denomination in the Latter Day Saint movement founded by Joseph Smith during the early 19th-century period of religious revival known as the Second Great Awakening.

Church theology includes the Christian doctrine of salvation only through Jesus Christ, and his substitutionary atonement on behalf of mankind. The church has an open canon which includes four scriptural texts: the Bible, the Book of Mormon, the Doctrine and Covenants, and the Pearl of Great Price. Other than the Bible, the majority of the church's canon consists of material the church's members believe to have been revealed by God to Joseph Smith; these include commentary and exegesis about the Bible, texts described as lost parts of the Bible, and other works believed to be written by ancient prophets, including the Book of Mormon. Because of doctrinal differences, Catholic, Orthodox, and many Protestant churches consider the church to be distinct and separate from mainstream Christianity.

Latter-day Saints believe that the church president is a modern-day "prophet, seer, and revelator" and that Jesus Christ, under the direction of God the Father, leads the church by revealing his will and delegating his priesthood keys to its president. The president heads a hierarchical structure with various levels reaching down from areas, stakes, to wards. Bishops, drawn from the laity, lead the wards. Male members may be ordained to the priesthood, provided they are living the standards of the church. Women are not ordained to the priesthood, but occupy leadership roles in some church organizations.

Both men and women may serve as missionaries; the church maintains a large missionary program that proselytizes and conducts humanitarian services worldwide. The LDS Church also funds and participates in humanitarian projects independent of its missionary efforts. Faithful members adhere to church laws of sexual purity, health, fasting, and Sabbath observance, and contribute ten percent of their income to the church in tithing. The church also teaches about sacred ordinances through which adherents make covenants with God, including baptism, confirmation, the sacrament, priesthood ordination, endowment, and celestial marriage.

The church has been criticized throughout its history. Modern criticisms include disputed claims, treatment of minorities, and financial controversies. The church’s practice of polygamy (called plural marriage) was also controversial until officially rescinded in 1890.