The Diocese of Niagara was founded in 1875. The diocese covers approximately 3,320 square miles in the province of Ontario. The most northern towns are Harriston and Mount Forest, to the west, Nanticoke, to the south, Fort Erie, and to the west Oakville. The diocese presently consists of the following archdeaconries: Wellington, Trafalgar, Wentworth-Haldimand, Hamilton, Lincoln, and Brock. These archdeaconries are further subdivided into deaneries: Wellington, Wentworth, Halton West, Trafalgar, Haldimand, Barton, Hamilton Central, Lincoln East, Lincoln West, Welland, and Niagara Falls.
There have been three histories written. Firstly, A. H. Young, "The Diocese of Niagara Before 1875," Canadian Journal of Religious Thought (Jan.-Feb. 1926) which covers the period before the Diocese of Niagara was created from the existing Diocese of Toronto in 1875. Secondly, History of the Diocese of Niagara to 1950 published by the Diocese in 1950 to mark its 75th Anniversary. There is a copy in Mills Library, general stacks, BX5612.N5A5, and a photocopy at the reference desk in Research Collections Reading Room. Thirdly, there is Some Men and Some Controversies, (1974) edited by Richard Ruggle, which contains a collection of essays, some dealing with the early history of the Niagara Diocese. It has not been catalogued; available in Research Collections Reading Room. Finally Parish Register A contains a history of the diocese up to 1925 in two volumes.