An apostolic vicariate is a form of territorial jurisdiction of the Roman Catholic Church established in missionary regions and countries that do not have a diocese. It is essentially provisional, though it may last for a century or more. The hope is that the region will generate sufficient numbers of Catholics for the Church to create a diocese.

An apostolic vicariate is led by a vicar apostolic who is usually a titular bishop. While such a territory can be classed as a particular church, according to canon 371.1 of the Latin Code of Canon Law, a vicar apostolic's jurisdiction is an exercise of the jurisdiction of the Pope — the territory thus comes directly under the pope as "universal bishop", and the pope exercises this authority through a “vicar” or delegate. This is unlike the jurisdiction of a diocesan bishop, whose jurisdiction derives directly from his office.

Like any ecclesiastical jurisdiction, an apostolic vicariate may be administered by the bishop of a neighbouring diocese, or by a priest appointed transitionally as an apostolic administrator. As in a regular diocese, the vicar apostolic may appoint priests as vicars exercising limited jurisdiction over the apostolic vicariate.