In Christian denominations, an archbishop is a bishop of higher rank or office. In most cases, such as the Catholic Church, there are many archbishops who either have jurisdiction over an ecclesiastical province in addition to their own archdiocese (with some exceptions), or are otherwise granted a titular archbishopric. In others, such as the Lutheran Church of Sweden, the title is only borne by the leader of the denomination.

The word archbishop (/ˌɑːrtʃˈbɪʃəp/) comes via the Latin archiepiscopus. This in turn comes from the Greek αρχιεπίσκοπος, which has as components the etymons αρχι-, meaning 'chief', επί, 'over', and σκοπός, 'guardian, watcher'.

The earliest appearance of neither the title nor the role can be traced. The title of "metropolitan" was apparently well known by the 4th century, when there are references in the canons of the First Council of Nicæa of 325 and Council of Antioch of 341, though the term seems to be used generally for all higher ranks of bishop, including patriarchs. The term "archbishop" does not appear in the modern sense until the 6th century, although the role, above ordinary bishops but below patriarchs, seems to be established for metropolitans by the 5th century.

Episcopal sees are generally arranged in groups in which one see's bishop has certain powers and duties of oversight over the others. He is known as the metropolitan archbishop of that see. In the Catholic Church, canon 436 of the Code of Canon Law indicates what these powers and duties are for a Latin Church metropolitan archbishop, while those of the head of an autonomous (sui iuris) Eastern Catholic Churches are indicated in canon 157 of the Code of Canons of the Eastern Churches. All Catholic metropolitans are archbishops, but not all archbishops are metropolitans, though most are.

As well as the much more numerous metropolitan sees, there are 77 Catholic sees that have archiepiscopal rank. In some cases, such a see is the only one in a country, such as Luxembourg or Monaco, too small to be divided into several dioceses so as to form an ecclesiastical province. In others, the title of archdiocese is for historical reasons attributed to a see that was once of greater importance.

Some of these archdioceses are suffragans of a metropolitan archdiocese; examples are the Archdiocese of Avignon, which is a suffragan of the Archdiocese of Marseille, and the Archdiocese of Trnava, Slovakia. Others are immediately subject to the Holy See and not to any metropolitan archdiocese. These are usually "aggregated" to an ecclesiastical province. An example is the Archdiocese of Hobart in Australia, associated with the Metropolitan ecclesiastical province of Melbourne, but not part of it. The ordinary of such an archdiocese is an archbishop.

In the Anglican Communion, non-metropolitan archiepiscopal sees are much less common. The Anglican Diocese of Jerusalem, established in 1841, was raised to the status of a non-metropolitan archiepiscopal see in 1957, but reduced to the status of an ordinary bishopric again in 1976. In 2014 it was again elevated to the status of non-metropolitan archbishopric, with its ordinary bearing the title "Archbishop in Jerusalem", despite having no ex officio right to be the metropolitan of the province.

Until 1970, a coadjutor archbishop, one who has special faculties and the right to succeed to the leadership of a see on the death or resignation of the incumbent, was assigned also to a titular see, which he held until the moment of succession. Since then, the title of Coadjutor Archbishop of the see is considered sufficient and more appropriate.