PETERBOROUGH, Diocese of. — In the province of Ontario, Canada. Pius IX founded the Apostolic Vicariate of Northern Canada on 3 Feb. 1874 with the bull *Arcano divinae Providentiae*, and Leo XIII elevated it to a diocese on 11 July 1882 with the bull *Quod Venerabiles Fratres*.
The Apostolic Vicariate of Northern Canada derived from a division of the Diocese of Ottawa, and the new diocese was made a suffragan of Kingston. It has a Catholic population of 27,000 souls; 51 diocesan priests and 4 religious (Redemptorists) attend to the spiritual care. There are 67 churches, 2 hospitals, 2 orphanages, and 29 parishes. The diocese covers an area of 10,047 square miles.
Bibl.: *Le Canada ecclésiastique*, Montréal 1930, pp. 450-54; *The Ontario year book and directory*, Toronto 1950.