The Diocese of Algoma was founded as a missionary diocese in 1873 and covers an area of 70,000 square miles of northern Ontario, south of the Diocese of Moosonee.  The Diocese of Algoma held its first independent Synod in June 1906.  The Synod office and Cathedral are in Sault Ste. Marie, Ontario.

The Diocese of Algoma had one long term residential school: Shingwauk Indian Residential School in Sault Ste. Marie, ON (1873-1969).