Ontario History
- Ancestral Roofs
- Andrew Hind
- Andy’s Northern Ontario Wildflowers
- Archeological Research Associates Ltd.
- Archives of Ontario
- Barbara Raué
- Barrie Historical Archive
- BarrieToday – Remember This
- BarrieToday – Then and Now
- Bruce County Historical Society
- Canada (Ontario) Beneath Our Feet
- Coniston Historical Group
- Conservation Ontario
- Copper Cliff Notes
- Doors Open Ontario
- Doors Open Whitchurch-Stouffville
- Esquesing Historical Society
- Etobicoke Historical Society
- Gloucester Historical Society
- Grenville County Historical Society
- Heritage Brockville
- Heritage North Bay
- Heritage Ottawa
- Heritage Toronto
- Hike Ontario
- Historic Westmeath Township
- Historical Maps of Toronto
- Historical Perceptions (Hamilton)
- Home | Tavistock
- Kingston Historical Society
- Lake Scugog Historical Society
- Lost Resting Places
- New Toronto Historical Society
- Northern Ontario Heritage Fund Corporation
- Official Website of Tourism in Ontario
- Old Ontario Postcards – Flickr
- Old Toronto Series
- onrgallery.com (Ontario Northland Railway)
- Ontario Architecture
- Ontario Black History
- Ontario Heritage Trust
- Ontario Historical Society
- Ontario Museums
- Ontario Nature
- Ontario Parks
- Ontario Plant Restoration Alliance
- Ontario’s Historical Plaques
- Orillia Heritage Centre
- Osgoode Township Historical Society
- Oshawa Historical Society
- Oshawa Journal
- Ottawa Past & Present
- Peterborough Historical Society
- Postcard Memories — Orillia Matters
- Postcards From the Bay – Wiarton
- Preserve Our Wrecks, Kingston
- Professional Engineers Ontario – History
- Railway Stations of Ontario
- Railways of Eastern Ontario
- Ramara Historical Society
- ReOntario
- Scarborough Historical Society
- Scugog Heritage Gallery
- Streets of Toronto
- Tay Township Heritage
- The Beachburg Sub – Ottawa Area
- The Historical Society of Ottawa
- The Toronto Dreams Project
- The Toronto Dreams Project Historical Ephemera Blog
- Today in Ottawa’s History
- Toronto Before
- Toronto Before
- Toronto Before – Facebook
- Toronto Postcard Club
- Toronto’s Historical Plaques
- Unknown Toronto
- Urban Toronto
- Vintage Postcards of Hamilton, Ontario
- VintagePostcards.org
- Voyageur Heritage Network