An archbishop (from Greek ἀρχι-, chief, and ἐπίσκοπος, bishop) is a bishop of higher rank, but not of higher sacramental order above that of the three orders of deacon, priest (presbyter), and bishop. Accordingly, a person does not become an archbishop by ordination.

Episcopal sees are generally arranged in groups in which the bishop who is the ordinary of one of them has certain powers and duties of oversight over the other sees. He is known as the metropolitan archbishop of that see. In the Roman Catholic Church, canon 436 of the Code of Canon Law indicates what these powers and duties are for a Latin Rite metropolitan archbishop, while those of the head of an autonomous (sui iuris) Eastern Catholic Church are indicated in canon 157 of the Code of Canons of the Eastern Churches.

As well as the much more numerous metropolitan sees, there are 77 Roman 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.

The Archbishop of Canterbury is the senior bishop and principal leader of the Church of England, the symbolic head of the worldwide Anglican Communion, and the diocesan bishop of the Diocese of Canterbury. In his role as head of the Anglican Communion, the archbishop leads the third largest group of Christians in the world^{[citation needed]}.

The current archbishop is the Most Reverend Rowan Williams. He is the 104th in a line which goes back more than 1400 years to St Augustine of Canterbury, the "Apostle to the English", in the year 597. From the time of St Augustine until the 16th century, the Archbishops of Canterbury were in full communion with the See of Rome and thus received the pallium. During the English Reformation the Church of England broke away from the authority of the Pope and the Roman Catholic Church, at first temporarily under Henry VIII and Edward VI and later permanently during the reign of Elizabeth I.

In the Middle Ages there was considerable variation in the methods of nomination of the Archbishop of Canterbury and other bishops. At various times the choice was made by the canons of Canterbury Cathedral, the King of England, or the Pope. Since the English Reformation, the Church of England has been more explicitly a state church and the choice is legally that of the British crown; today it is made in the name of the Sovereign by the Prime Minister, from a shortlist of two selected by an ad hoc committee called the Crown Nominations Commission.