Bryan McAllister’s personal reference notebook
July 27, 2026Short & citedBlog
Civic Viewpoint.
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Kept by Bryan McAllister — short guides, clear facts, and the Canadian angle when it matters.
Field Notes • Canada Places

Ontario

Ontario is a province in east-central Canada and the country’s most populous province.

Updated July 27, 20261 min readCited sources

Ontario is Canada’s most populous province, located in east-central Canada. Its capital is Toronto, and the national capital, Ottawa, is also within its borders.

What it is

Ontario is one of Canada’s ten provinces, bordered by Manitoba to the west, Quebec to the east, Hudson Bay and James Bay to the north, and the Great Lakes and the United States to the south. It is the second-largest province by area after Quebec.

Key details

The province covers 1,076,395 km² and uses the postal abbreviation ON. Its official road map has been produced since 1923 and is updated every two years. Maps typically show boundaries, coastlines, major lakes and rivers, roads, and municipal divisions.

Why it matters

Ontario is central to Canada’s population, economy, and transportation network. It contains both Toronto and Ottawa, making it especially significant for Canadian readers.

In short

  • Most populous Canadian province
  • Capital is Toronto; national capital Ottawa is also in Ontario
  • Second-largest province by area
  • Official road map produced since 1923, updated every two years
Canadian angle

Ontario is central to Canada’s population, economy, and transportation network, and it contains both Toronto and Ottawa, making it especially significant for Canadian readers.

Quick questions

What is Ontario?
Ontario is a Canadian province in east-central Canada and the country’s most populous province.
What is the capital of Ontario?
Toronto is the capital of Ontario.
What is Ontario’s official abbreviation?
ON.

Sources

  1. Government of Ontario — http://www.ontario.ca/page/official-road-map-ontario
    Supports: Official road map history and publication cycle; Ontario road map features.
  2. Government of Canada Open Government Portal — https://open.canada.ca/data/en/dataset/77cbc287-6b17-5ab6-bf2d-d61cee44356c
    Supports: Outline map of Ontario with boundary, coastline, and major lakes and rivers.
  3. Government of Ontario — https://www.ontario.ca/page/maps-ontario
    Supports: General Ontario maps page.
  4. Natural Resources Canada — https://natural-resources.canada.ca/maps-tools-publications/maps/atlas-canada/reference-maps
    Supports: Political, outline, and relief reference maps of Ontario.
  5. Geology.com — https://geology.com/canada/ontario.shtml
    Supports: Ontario borders and geographic location.