High priest

The term "high priest" usually refers either to an individual who holds the office of ruler-priest, or to one who is the head of a religious organisation.

Ancient Egypt

In ancient Egypt, a high priest was the chief priest of any of the many gods revered by the Egyptians.

While not regarded as a dynasty, the High Priest of Amun at Thebes, Egypt were nevertheless of such power and influence that they were effectively the rulers of Upper Egypt from 1080 to
High Priest of Osiris. The main cult of Osiris was in Abydos, Egypt.
High Priest of Ptah. The main cult of Ptah was in Memphis, Egypt.
High Priest of Ra. The main cult of Ra was in Heliopolis.
God's Wife of Amun – the highest-ranking priestess of the Amun cult

Ancient Israel

The High Priest of Israel served in the Tabernacle, then in Solomon's Temple and the Second Temple in Jerusalem. The Samaritan High Priest is the high priest of the Samaritans.

Ancient world

Archiereus, title of a high priest from Ancient Greece
Dastur, a Zoroastrian high priest
Hierophant, the chief priest of the Eleusinian Mysteries
NIN (cuneiform) or EN (cuneiform), a high priest or priestess of a city-state's patron-deity in Sumer
Pontifex maximus from Ancient Rome
Pythia, high priestess of the Temple of Apollo (Delphi)

China

Zhang Lu was the third generation of Celestial Masters lineage from Zhang Daoling, was a high priest and appointed as General of the Household Who Guards Civilians and the Administrator of Hanning by imperial government.
Kou Qianzhi was conferred as the high priest or Tian Shi by Emperor Taiwu of Northern Wei, which eventually established The Northern Celestial Masters.

India

Vidyaranya was a high priest in the Vijayanagara Empire.Panditrao was a title of the appointed high priest that sat on the Council of 8 in the early Maratha Empire.
The title of high priest is used in the Śvētāmbara sect of Jainism.

Christianity

The Epistle to the Hebrews refers to Jesus as high priest.
Christian usage refers to Jesus Christ as the only high priest, for example in Catholic teaching he is described as "high priest of the new and eternal covenant". Jesus' prayer as recorded in John 17 was called the precatio summi sacerdotis or "prayer of the high priest" by the Lutheran theologian David Chytraeus and earlier Church Fathers used similar terminology to refer to Jesus and his prayer in this chapter.
A high priest could sometimes be compared to the Pope in the Catholic Church, to a patriarch in the Oriental Orthodox Churches, the Church of the East and the Eastern Orthodox Churches or to a primate in the Anglican Communion. Throughout the episcopal body, except in the Anglican and Lutheran communions, bishops may also be referred to as high priests, since they share in or are considered earthly instruments of the high priesthood of Jesus Christ.
High priest is an office of the priesthood within the Melchizedek priesthood in most denominations of the Latter Day Saint movement.

Mandaeism

A high priest in Mandaeism is known as a ganzibra. The head of all of the high priests within a Mandaean community is known as a rishama.

Other religions

The Celestial Masters was founded by Zhang Daoling in 142 CE, they have been the high priests and spiritual leaders in Zhengyi Order of Taoism until present days. The 63rd Celestial Master, Zhang En Pu eventually migrated to Taiwan in 1949.
The 16th-century Maya priesthood was headed by a high priest who instructed the other priests and advised the king.
Kahuna Nui, presides over the temple or heiau. Below the Kahuna Nui are various types and ranks of priests.
In Nichiren Shoshu Buddhism, the High Priest is considered to be successor to Nichiren, through the lineage of Nikko Shonin.
The Dalai Lama is the head of the Gelug school of Tibetan Buddhism.
Chief Rabbi is the title given in several countries to the recognized religious leader of that country's Jewish community, or to a rabbinic leader appointed by the local secular authorities. Since 1911 Israel has had two chief rabbis, one Ashkenazi and one Sephardi.
In Shinto, a high priest, called a Guji, is usually the highest-ranking priest in a shrine.
Grand Mufti is the title for the leading Islamic jurist of a country, typically Sunni, who may oversee other muftis.
The Grand Imam of al-Azhar is considered, by most Muslims, to be the highest authority in Sunni Islamic thought and Islamic jurisprudence and holds great influence on followers of the theological Ash'ari and Maturidi traditions worldwide.
In Ásatrú, the high priest is called a goði and is the leader of a small group of practitioners collectively referred to as a Kindred. The goði are collectively known as the goðar. Some countries use the term Allsherjargoði for national multi-kindred organizations, most notably Iceland's.
In both the Yoruba religion and a number of its various New World sects, such as Santeria, a high priest is called a Babalawo. The term means wise man, and comes from the Yoruba language of West Africa. A female holder of the title is known as an Iyanifa.
In Wicca, High Priest and High Priestess are the roles of the man and woman who are leading a group ritual. High Priest and High Priestess are also titles sometimes conferred on the members of a Wiccan coven when they have completed their third, or fifth year of study and practice. Sometimes called Third degree, depending on path or tradition.
The High Priest and High Priestess are the two highest positions of leadership and administration within the Church of Satan.
In some Rodnover organisations in Russia, the volkhv is the title used for the high priest, or priests in higher ranks.
In Tio religion, the Lipie acted as the Tio Kingdom's high priest.

Non-religious usages

The phrase is also often used to describe someone who is deemed to be an innovator or leader in a field of achievement. For example, an 1893 publication describes ancient Greek playwright Aristophanes as having been "the high-priest of comedy".