The Archdiocese of Grouard–McLennan was erected on April 8, 1862 as the Apostolic Vicariate of Athabaska Mackenzie, on territory split off from the Diocese of Saint-Boniface. A month later on May 8, 1862, Henri Faraud, O.M.I. was appointed as Apostolic Vicar. Bishop Faraud served until March 20, 1890 when he resigned. He was succeeded by Émile Grouard, O.M.I. who was appointed Apostolic Vicar on October 18, 1890. Bishop Faraud and later Bishop Grouard were assisted by Isidore Clut, O.M.I. who was appointed Auxiliary Bishop on August 3, 1864 and who served until his death on July 9, 1903. On July 3, 1901, the territory of the Vicariate was split, remaining as the Apostolic Vicariate of Athabaska, which comprised what is today the northwestern area of the Province of Alberta, but losing the then Apostolic Vicariate of Mackenzie, which comprised what today is the Northwest Territories as well as northeastern area of the Province of Alberta. Bishop Grouard remained as the Apostolic Vicar of Athabaska and Gabriel Breynat, O.M.I. was appointed Apostolic Vicar of Mackenzie. A few years after the death of Bishop Clut, Celestin_Henri Joussard, O.M.I. was appointed Coadjutor Apostolic Vicar on May 11, 1909. On March 15, 1927, the name of the Vicariate was changed from the Apostolic Vicariate of Athabaska to the Apostolic Vicariate of Grouard. Bishop Joussard never ended up succeeding Bishop Grouard as Apostolic Vicar of Athabaska and both Bishop Grouard and Bishop Joussard retired on April 18, 1929. Following the retirement of Bishop Grouard, Joseph Guy, O.M.I. was appointed Vicar Apostolic of Grouard on December 19, 1929. Bishop Guy served until June 2, 1937 when he was appointed the Bishop of Gravelbourg. The following year on March 30, 1938, Ubald Langlois, O.M.I. was appointed Apostolic Vicar of Grouard. On June 15, 1945, Henri Routhier, O.M.I. was appointed Coadjutor Apostolic Vicar. In 1946 Bishop Langlois transferred the seat of the Vicariate from Grouard to McLennan. The Town of Grouard, taking its name from Bishop Grouard when it was incorporated as a town on September 27, 1909, was a thriving community of approximately 1,200 people. This changed when the Edmonton, Dunvegan and British Columbia Railway built its new line south of Lesser Slave Lake instead of going through Grouard which was on the north shore of Lesser Slave Lake. The majority of Grouard’s population moved to High Prairie, the newly established town on the railway. Bishop Grouard had originally established a mission at the Lesser Slave Lake settlement, the original name of Grouard, under the patronage of Saint Bernard, in 1872. Shortly after the Seat of the Vicariate was transferred to McLennan, work began on a new Cathedral dedicated to Saint John the Baptist. Bishop Langlois served as Apostolic Vicar of Grouard until his death on September 18, 1953. Upon Bishop Langlois death, Bishop Routhier immediately succeeded him as Apostolic Vicar of Grouard. On July 13, 1967, the Apostolic Vicariate of Grouard was elevated to the Archdiocese of Grouard–McLennan and made the Metropolitan See of northwestern Canada with the newly elevated Dioceses of Prince George, Mackenzie-Fort Smith and Whitehorse as suffragans, but the Diocese of Prince George was later transferred to the Ecclesiastical Province of British Columbia. On this date all the Apostolic Vicariates in northern Canada were elevated to dioceses. Archbishop Routhier served until his resignation on November 21, 1972, he was succeeded by Henri Légaré, O.M.I., who had been Bishop of Labrador-Schefferville. Archbishop Légaré served until his retirement on July 16, 1996. On the same day Henri Goudreault, O.M.I., who had also served as Bishop of Labrador City-Schefferville, was appointed to succeed him. Archbishop Goudreault died suddenly of a heart attack on July 23, 1998. The Archdiocese of Grouard–McLennan remained vacant until the appointment of Arthé Guimond, who had served as Archdiocesan Administrator, on June 9, 2000. Archbishop Guimond retired on November 30, 2006 and Gérard Pettipas, C.Ss.R. was appointed to succeed him on the same day.
Célestin-Henri Joussard, O.M.I., as Coadjutor Vicar Apostolic; did not succeed to see
Henri Routhier, O.M.I., as Coadjutor Vicar Apostolic
Auxiliary bishop
Isidore Clut, O.M.I.
Extent and statistics
Its ecclesiastic territory includes the northwest section of the Province of Alberta, the boundaries of which are, on the north the 60th parallel north, separating it from the Northwest Territories and the Diocese of Mackenzie-Fort Smith. To the south the 55th parallel north, separating it from the Diocese of Saint Paul. On the east the 113th meridian west, separating it from the Diocese of Saint Paul and the Diocese of Mackenzie-Fort Smith. To the west the 120th meridian west, separating it from the Province of British Columbia, and the Diocese of Prince George. As per 2014, the archdiocese pastorally served 59,927 Catholics on 224,596 km² in 33 parishes with 26 priests, 2 deacons, 20 lay religious and 3 seminarians.