A bishop (English derivation from the New Testament of the Christian Bible Greek ἐπίσκοπος, ep\xedskopos, "overseer", "guardian") is an ordained, consecrated, or appointed member of the Christian clergy who is generally entrusted with a position of authority and oversight.

Within the Roman Catholic, Eastern Orthodox, Oriental Orthodox, Anglican, Old Catholic and Independent Catholic churches and in the Assyrian Church of the East, bishops claim apostolic succession, a direct historical lineage dating back to the original Twelve Apostles. Within these churches, bishops are seen as those who possess the full priesthood and can ordain clergy – including other bishops. Some Protestant churches including the Lutheran and Methodist churches have bishops serving similar functions as well, though not always understood to be within apostolic succession in the same way.