An ecclesiastical province is a unit of religious government existing in certain Christian churches. It consists of a metropolitan archdiocese and a number of other dioceses known as suffragan sees. The archbishop of the metropolitan see is the metropolitan of the province.

In the Roman Catholic Church, the authority of the metropolitan over the suffragan sees is very limited (for example, during a vacancy, a Roman Catholic metropolitan can name a temporary administrator if the College of Consultors fail to elect one within a set time and the Pope has not named an apostolic administrator). In the United States Roman Catholic ecclesiastical provinces typically follow state lines, with less populous states being typically grouped into provinces and more populous states being a province by themselves. California and Texas are the only states in multiple provinces, each having two archdioceses.

In the Anglican Communion, national churches are often by themselves considered a "province", whether or not their head bears the title of Archbishop; the Church of England divides England into two provinces under the Archbishops of Canterbury and York, and uses the term suffragan bishop not for the bishops of dioceses in the provinces, but for assisting bishops within each diocese. The Anglican Church of Australia, the Anglican Church of Canada, the Church of Ireland, the Church of Nigeria and the Episcopal Church in the United States of America are all also divided into two or more provinces.