Mormon cosmology is the description of the history, evolution, and destiny of the physical and metaphysical universe according to Mormonism, which includes the doctrines taught by leaders and theologians of the Church of Jesus Christ of Latter-day Saints (LDS Church), Mormon fundamentalism, and other denominations within the Latter Day Saint movement. Mormon cosmology draws from Biblical cosmology, but has many unique elements provided by movement founder Joseph Smith. These views are not generally shared by adherents of other Latter Day Saint movement denominations who do not self-identify as "Mormons", such as the Community of Christ.

According to Mormon cosmology, there was a pre-existence, or a pre-mortal life, in which human spirits were literal children of heavenly parents. Although their spirits were created, the essential "intelligence" of these spirits is considered eternal, and without beginning. During this pre-mortal life, a Plan of Salvation was presented by God the Father (Elohim) with Jehovah (the premortal Jesus) championing moral agency but Lucifer (Satan) countered with a plan that abolished individual choice, and promised eternal exaltation to all, regardless of individual desire. This alternative plan, while seemingly more equitable, was actually contingent on the glory of God being bestowed solely on Lucifer himself. Thus, Lucifer is referred to as "The Great Deceiver" by prominent Mormon Apostle Marion G. Romney. When Lucifer's plan was not accepted, he rebelled against God the Father and was cast out of heaven, taking "the third part" of the hosts of heaven with him to the earth, thus becoming the tempters.

According to the Plan of Salvation, under the direction of God the Father, Jehovah created the earth as a place where humanity would be tested. After the resurrection, all men and women—except the spirits that followed Lucifer and the sons of perdition—would be assigned one of three degrees of glory. Within the highest degree, the celestial kingdom, there are three further divisions, and those in the highest of these celestial divisions would become gods and goddesses through a process called "exaltation" or "eternal progression". The doctrine of eternal progression was succinctly summarized by LDS Church leader Lorenzo Snow: "As man now is, God once was: As God now is, man may be." According to Smith's King Follett discourse, God the Father once passed through mortality as Jesus did, but how, when, or where that took place is unclear. A prevailing view among Mormons is that God once lived on a planet with his own higher god.

According to Mormon scripture, the Earth's creation was not ex nihilo, but organized from existing matter. The Earth is said to be just one of many inhabited worlds, and there are many governing heavenly bodies, including the planet or star Kolob, which is said to be nearest the throne of God.

In Mormonism, the concept of divinity centers around an idea of "exaltation" and "eternal progression": mortals themselves may become gods and goddesses in the afterlife, be rulers of their own heavenly kingdoms, have spirit children, and increase in power and glory forever. Mormons understand that there is a Heavenly Mother. However, the three persons of Godhead (God the Father, Jesus, and the Holy Ghost) are to be the only objects of worship.

In LDS doctrine, the goal of each adherent is to receive "exaltation" through the atonement of Jesus. If a person receives exaltation, they inherit all the attributes of God the Father, including godhood. Mormons believe that these people will become gods and goddesses in the afterlife, and will have "all power, glory, dominion, and knowledge." Mormons teach that exalted people will live with their earthly families and will also "have spirit children": their posterity will grow forever.

According to the belief, exaltation is a gift available only to those who have qualified for the highest "degree" of the celestial kingdom through faith in Jesus and obedience to his commandments. As prerequisites for this "greatest gift of God", adherents believe that in the afterlife, they will become "perfect" and they must participate in all the required ordinances. Though not necessary, their exaltation can be "sealed upon them" by the Holy Ghost via the second anointing ordinance. One of the key qualifications for exaltation is being united in a celestial marriage to an opposite-sex partner via the ordinance of sealing, either in person or by proxy after they have died. In the 19th century, some leaders of the LDS Church taught that participation in plural marriage was also a requirement of exaltation. The LDS Church abandoned the practice beginning in 1890 and now teaches that only a single celestial marriage is required for exaltation.

According to Mormon theology, God the Father is a physical being of "flesh and bones." Mormons identify him as the biblical god Elohim. Latter-day Saint leaders have also taught that God the Father was once a mortal man who has completed the process of becoming an exalted being. According to Joseph Smith, God "once was a man like one of us and [...] once dwelled on an earth the same as Jesus Christ himself did in the flesh and like us."