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.

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

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.

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 (the Ecumenical Patriarch of Constantinople is a primus inter pares) or to a primate in the Anglican Communion (the Archbishop of Canterbury is a primus inter pares). Throughout the episcopal body, except in the Anglican and Lutheran communions, bishops may also be referred to as high priests,^{[citation needed]} 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.

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.