The Personal Apostolic Administration of Saint John Mary Vianney was established on 18 January 2002 by Pope John Paul II for traditionalist Catholic clergy and laity within the Diocese of Campos in Brazil. It is the only personal apostolic administration in existence, and the only canonically regular Catholic Church jurisdiction devoted exclusively to celebrating the pre-1965 form of the Roman Rite in the area. Its current Apostolic Administrator is Bishop Fernando Arêas Rifan.

Traditionalist Catholicism is a movement that emphasizes beliefs, practices, customs, traditions, liturgical forms, devotions and presentations of teaching associated with the Catholic Church before the Second Vatican Council (1962–1965). Traditionalist Catholics particularly emphasize the Tridentine Mass, the Roman Rite liturgy largely replaced in general use by the post-Second Vatican Council Mass of Paul VI.