Our Diocese Prior to 1904, Catholics in Northern Ontario were under the jurisdiction of the Diocese of Peterborough. Faced with an ever-growing Catholic population, Bishop Richard O'Connor saw the need to divide the territory and create another diocese. The idea was presented to Pope Pius X and the Diocese of Sault Ste. Marie was officially founded in 1904.
The Diocese of Sault Ste. Marie was formally established on September 16th, 1904 and the City of Sault Ste. Marie was chosen for the new cathedral because it was geographically in the middle of the diocese. The Most Reverend David Joseph Scollard was ordained to the Episcopacy on February 24th, 1905 and became the first bishop of diocese. Though Sault Ste. Marie would always remain the Episcopal See of the diocese, neither Bishop Scollard nor any of his successors would reside in Sault Ste. Marie, but rather in North Bay, and eventually Sudbury.
At its founding, the territory of the diocese extended west from Callander, Ontario for 1280 kilometres, almost reaching the Manitoba border. During the episcopacy of the second Bishop, Bishop Ralph Hubert Dignan (1935-1958), the western end of the diocese was separated on August 26th, 1952 to form the Diocese of Port Arthur, now known as the Diocese of Thunder Bay. His Excellency, the Most Reverend Alexander Carter (1958-1985) was the third Diocesan Bishop and was succeeded by his Excellency, the Most Reverend Marcel Gervais (1985-1989) who subsequently became the Archbishop of Ottawa. On January 12th, 1990, Bishop Jean-Louis Plouffe was installed as Ordinary of the Diocese of Sault Ste. Marie. On November 12th, 2015, His Holiness Pope Francis appointed Bishop Marcel Damphousse as the sixth Bishop of the Diocese of Sault Ste. Marie until May 2020 when he was appointed Coadjutor Archbishop of Ottawa-Cornwall. In October 2020, Pope Francis appointed Bishop Thomas Dowd as the seventh Bishop of the Diocese of Sault Ste. Marie.
The Diocese of Sault Ste. Marie now comprises the Districts of Sudbury and Algoma; and includes portions of Nipissing District north and west of Lake Nipissing, and also includes Manitoulin Island. The diocese is divided into 4 pastoral regions: Nipissing, Sudbury, Manitoulin-North Shore, and Algoma with three major population centres Sault Ste. Marie, Sudbury and North Bay.