In Mormonism, the Aaronic Priesthood is the lower of two forms of priesthood. The other form of priesthood is the Melchizedek Priesthood. While the Melchizedek Priesthood is modeled after the New Testament authority of the Apostles, the Aaronic Priesthood is modeled after the Old Testament Levitical priesthood.

Like the Melchizezek Priesthood, Mormons believe that Aaronic Priesthood authority is passed through the laying on of hands: "[A] man must be called of God, by prophecy, and by the laying on of hands by those who are in authority, to preach the Gospel and administer in the ordinances thereof." (5th Article of Faith).

The Aaronic Priesthood is sometimes considered to be a "branch" or an "appendage" to the Melchizedek Priesthood.

Offices of the Aaronic Priesthood

Aaronic Priesthood
Bishop18 and olderPreside over local wards (congregations), administer temporal and spiritual welfare to their wards and officiate as a common judge in Israel; a Bishop is also President of the Aaronic Priesthood in his ward; a literal descendant of Levi is entitled to this office, but it may be filled by a High Priest if no Levitical descendant is present in the ward. The Bishop is typically the presiding High Priest in a congregation
Priest16 and olderPrepare and Bless the Sacrament, Baptize, ordain other Priests, Teachers and Deacons and all the duties of a Teacher
Teacher14 and olderPrepare the Sacrament, Hometeach and all the duties of a Deacon
Deacon12 and olderKeys of the ministering of angels, pass the Sacrament and collect Fast Offerings

In the Church of Jesus Christ of Latter-day Saints, if an adult man joins the Church, he may be called and ordained to hold the Aaronic Priesthood (if he is morally worthy) by those in the Church with authority to do so. After a period of time (usually one year) the man may be called and ordained to receive the Melchizedek Priesthood (again based upon moral worthiness) by those in the Church with authority. In addition to being ordained to a certain office in the Aaronic or Melchizedek Priesthood, a male may also be set apart and ordained to a Priesthood leadership office. For example, men are usually not ordained to the office of High Priest unless they are also set apart to an office which requires that ordination, such as Bishop or High Councilman. However, older men are also ordained to the office of High Priest although they may have never been set apart to serve in a leadership office. Each person who holds an office of the Aaronic or Melchizedek Priesthood also belong to a local Priesthood quorum.

Mormons believe that ancient prophets and apostles conferred the Priesthood directly upon Joseph Smith and other early members of the Church. The conferral of the Aaronic Priesthood on Joseph Smith and Oliver Cowdery is recorded in Joseph Smith - History as follows:

"[W]e. . . went into the woods to pray and inquire of the Lord respecting baptism for the remission of sins, that we found mentioned in the translation of the plates[, The Book of Mormon]. . . . While we were thus employed, praying and calling upon the Lord, a messenger from heaven descended in a cloud of light, and having laid his hands upon us, he ordained us, saying:

"Upon you my fellow servants, in the name of Messiah, I confer the Priesthood of Aaron, which holds the keys of the ministering of angels, and of the gospel of repentance, and of baptism by immersion for the remission of sins; and this shall never be taken again from the earth until the sons of Levi do offer again an offering unto the Lord in righteousness.

"He said this Aaronic Priesthood had not the power of laying on hands for the gift of the Holy Ghost, but that this should be conferred on us hereafter; and he commanded us to go and be baptized, and gave us directions that I should baptize Oliver Cowdery, and that afterwards he should baptize me.

"Accordingly we went and were baptized. . . .

"The messenger who visited us on this occasion and conferred this Priesthood upon us, said that his name was John, the same that is called John the Baptist in the New Testament, and that he acted under the direction of Peter, James and John, who held the keys of the Priesthood of Melchizedek, which Priesthood, he said, would in due time be conferred on us, and that I should be called the first Elder of the Church, and he (Oliver Cowdery) the second. . . .

"Immediately on our coming up out of the water after we had been baptized, we experienced great and glorious blessings from our Heavenly Father. No sooner had I baptized Oliver Cowdery, than the Holy Ghost fell upon him, and he stood up and prophesied many things which should shortly come to pass. And again, so soon as I had been baptized by him, I also had the spirit of prophecy, when, standing up, I prophesied concerning the rise of this Church, and many other things connected with the Church, and this generation of the children of men. We were filled with the Holy Ghost, and rejoiced in the God of our salvation."