While an Ordinariate is a jurisdiction equivalent to that of a diocese, it is not defined geographically by city or territory, but by a unique and significant pastoral need that requires more flexibility. Within the territory of a particular Conference of Bishops, one or more Ordinariates may be erected as needed.

With the Apostolic Constitution Anglicanorum Coetibus dated 2009, Pope Benedict XVI established provisions for the erection of personal Ordinariates for Anglicans entering into full communion with the Catholic Church. Such Ordinariates are erected by the Congregation for the Doctrine of the Faith within the confines of the territorial boundaries of a particular Conference of Bishops in consultation with that same Conference. They are composed of lay faithful, clerics and members of Institutes of Consecrated Life and Societies of Apostolic Life, originally belonging to the Anglican Communion and now in full communion with the Catholic Church, or those who receive the Sacraments of Initiation within the jurisdiction of the Ordinariate.

Saint John the Evangelist Roman Catholic Church, Calgary, Alberta, of the Personal Ordinarite of the Chair of Saint Peter.

The personal Ordinariate in Canada, named after the Chair of Saint Peter, was first erected by the Holy See on the Solemnity of Mary, Mother of God, 1 January 2012, in order to cover the U.S. and was subsequently extended to include Canada in December of the same year, following consultation with the Canadian Conference of Catholic Bishops. As stated in the Apostolic Constitution and on the website of the Ordinariate of the Chair of Saint Peter, the purpose of such Ordinariates is to be an instrument of Catholic unity: an opportunity to model what the future reconciliation of separated Christian communities could be.

The Ordinariate has established the Deanery of St. John the Baptist based in Calgary, Alberta, to minister to groups of Anglicans and Anglican clergy in Canada who come into full communion with the Catholic Church (contact details below).