Ontario
see also: List of Cathedrals in Toronto
- St. Finnan Cathedral, in Alexandria (Roman Catholic)
- St Matthew's Cathedral in Cambridge (Independent Anglican Church Canada Synod)
- Co-Cathedral of the Nativity, in Cornwall (Roman Catholic)
- Christ's Church Cathedral, in Hamilton (Anglican)
- Christ the King Cathedral, in Hamilton (Roman Catholic)
- Notre-Dame-de-l'Assomption Cathedral, in Hearst (Roman Catholic)
- St. Alban's Cathedral, in Kenora (Anglican)
- St. George's Cathedral, in Kingston (Anglican)
- St. Mary's Cathedral, in Kingston (Roman Catholic)
- St. Paul's Cathedral, in London (Anglican)
- St. Peter's Cathedral, in London (Roman Catholic)
- Cathedral of the Transfiguration of Our Lord, in Markham (Slovak Byzantine Catholic)
- Christ the King Cathedral, in Moosonee (Roman Catholic)
- Trinity Reformed Episcopal Church Cathedral, in New Liskeard
- Assumption Pro-Cathedral, in North Bay (Roman Catholic)
- Cathedral of the Annunciation in Ottawa (Anglican Catholic)
- Christ Church Cathedral, in Ottawa (Anglican)
- Holy Trinity Cathedral, in Ottawa (Orthodox)
- Notre-Dame Cathedral Basilica, in Ottawa (Roman Catholic)
- St. Columbkille Cathedral, in Pembroke (Roman Catholic)
- St. Peter-in-Chains Cathedral, Peterborough (Roman Catholic) Constructed in 1837-38 to serve the Irish-Catholic population of the Robinson Settlement, St. Peter's became a cathedral in 1882. It is one of the oldest Roman Catholic churches remaining in Ontario. Despite renovations and additions, it has retained a Gothic Revival style.
- Cathedral of St. Catherine of Alexandria, in St. Catharines (Roman Catholic)
- Precious Blood Cathedral
- St. Patrick Cathedral, in Thunder Bay (Roman Catholic)
Read more about this topic: List Of Cathedrals In Canada