Primate (/ˈpraɪmət/) is a title or rank bestowed on some important archbishops in certain Christian churches. Depending on the particular tradition, it can denote either jurisdictional authority (title of authority) or (usually) ceremonial precedence (title of honour).

In the Latin Church, a primate is an archbishop—or, rarely, a suffragan or exempt bishop—of a specific (mostly metropolitan) episcopal see (called a primatial see) who has precedence over the bishoprics of one or more ecclesiastical provinces of a particular historical, political or cultural area. Historically, primates of particular sees were granted privileges including the authority to call and preside at national synods, jurisdiction to hear appeals from metropolitan tribunals, the right to crown the sovereign of the nation, and presiding at the investiture (installation) of archbishops in their sees.

The office is generally found only in older Catholic countries, and is now purely honorific, enjoying no effective powers under canon law—except for the archbishop of Esztergom (Gran) in Hungary. Thus, e.g., the primate of Poland holds no jurisdictional authority over other Polish bishops or their dioceses, but is durante munere a member of the standing committee of the episcopal conference, and has honorary precedence among Polish bishops (e.g., in liturgical ceremonies). The Holy See has also granted Polish primates the privilege of wearing cardinal's crimson attire, except for the skullcap and biretta, even if they have not been made cardinals.

Where the title of primate exists, it may be vested in one of the oldest archdioceses in a country, often based in a city other than the present capital, but which was the capital when the country was first Christianized. The city may no longer have the prominence it had when the title was granted. The political area over which primacy was originally granted may no longer exist: for example, the Archbishop of Toledo was designated "Primate of the Visigothic Kingdom", and the Archbishop of Lyon is the "Primate of the Gauls". The title of Primate can, therefore, also be disputed between different Archdioceses who, at some point, held proeminence over a shifting territory; such is the dispute over the Primacy of the Spains that was fought over by the Archdioceses of Braga, Toledo and Santiago de Compostela. After the founding of Portugal, the Archbishop of Braga held precedence over all other archbishops in the country, though his role declined under the rise of the Archdiocese of Lisbon, which culminated in 1716, when Archbishop Tomás de Almeida (1670–1754) was elevated to Patriarch.

Some of the leadership functions once exercised by Primates, specifically presiding at meetings of the bishops of a nation or region, are now exercised by the president of the conference of bishops: "The president of the Conference or, when he is lawfully impeded, the vice-president, presides not only over the general meetings of the Conference but also over the permanent committee." The president is generally elected by the conference, but by exception the President of the Italian Episcopal Conference is appointed by the Pope, and the Irish Catholic Bishops' Conference has the Primate of All Ireland as president and the Primate of Ireland as vice-president. Other former functions of primates, such as hearing appeals from metropolitan tribunals, were reserved to the Holy See by the early 20th century. Soon after, by the norm of the Code of Canon Law of 1917, confirmed in the 1983 Code, the tribunal of second instance for appeals from a metropolitan tribunal is "the tribunal which the metropolitan has designated in a stable manner with the approval of the Apostolic See".

The closest equivalent position in the Eastern Churches in 1911 was an Exarch.

The Holy See has continued in modern times to grant the title of Primate. With the papal decree Sollicitae Romanis Pontificibus of 24 January 1956 it granted the title of Primate of Canada to the Archbishop of Quebec. As stated above, this is merely an honorary title involving no additional power.

A right of precedence over other bishops and similar privileges can be granted even to a bishop who is not a Primate. Thus, in 1858, the Holy See granted the Archbishop of Baltimore precedence in meetings of the United States bishops. The Archbishop of Westminster has not been granted the title of Primate of England and Wales, which is sometimes applied to him, but his position has been described as that of "Chief Metropolitan" and as "similar to" that of the Archbishop of Canterbury.