Southern Ontario is the portion of the Canadian province of Ontario lying south of the French River and Algonquin Park. Depending on the inclusion of the Parry Sound and Muskoka districts, its surface area would cover between 14-15% of the province. It is the southernmost region of Canada.
Southern Ontario contrasts very greatly from Northern Ontario. The region has a much larger population, different climate, and much different culture than its Northern counterpart. Northern Ontario and Southern Ontario can almost be viewed as two different provinces due their many dissimilarities. Southern Ontario can also be broken into smaller subregions, such as Eastern Ontario, Central Ontario, Southwestern Ontario, and the Golden Horseshoe which includes the Greater Toronto Area.
Southern Ontario can be distinguished from Northern Ontario because it is far more densely populated and contains the majority of the province's cities, major roads, and institutions. Southern Ontario contains 94 per cent, or 12.1 million, of Ontario's total population of 12.9 million people, while the north, in contrast, contains more natural resources and remote wilderness. Although it has no saltwater coastline, it has an abundance of fresh water coastline on three of the Great Lakes Huron, Erie and Ontario and smaller inland lakes, notably Lake Simcoe and Lake St. Clair part of the Great Lakes system. It is a major vineyard region and producer of Canadian wines.
While Southern Ontario has been a part of the province of Ontario since its establishment, having previously formed the colony of Upper Canada, a large portion of the north did not become part of Ontario until 1912, 45 years after Ontario entered Confederation and the idea of a dissolution is discussed from time to time, mostly in the North.
Southern Ontario is home to over 12 million people, compared to fewer than 800,000 in the North. This is due to many factors including the more arable land in the south, its more moderate climate, well-used transportation (water, land and air) routes, proximity to populated areas of the Northeastern and Midwestern United States, as well as a long history of early settlers, and colonialism.
Southern Ontario was first colonized by the British and the French. After the area was established, other European immigrants arrived as well, and later many immigrants from other parts of the world. The region still has many Native Indian communities as well, with combined populations of over 200,000.
The region is one of the top destinations for immigrants worldwide. Some of the most well-known cities of Southern Ontario are Barrie, Guelph, Hamilton, Kingston, Kitchener, London, Peterborough, St. Catharines-Niagara, Waterloo, and Windsor, and largest among them, Toronto and Ottawa.
The area has a large manufacturing sector. Since the mid 2000's, Ontario produces more vehicles per year than the state of Michigan.Template:Citation needed Southern Ontario is part of the Rust Belt.  Factory closings are still taking their toll on the region's cities. The Province's two largest cities Toronto and Ottawa, however, are very service oriented, although Toronto still has a strong industrial presence. Toronto is the site of all of the major Canadian banks and its heart the financial sector including the Toronto Stock Exchange, while Ottawa, the capital of Canada is more heavily dependant on the public sector.
Some parts of Southern Ontario are heavily entwined with bordering cities in New York and Michigan both in terms of industry and people. The focus areas are the Niagara Region, Sarnia and Detroit-Windsor. Many people work and live on opposite sides of the border. The NEXUS program is increasing in popularilty amongst bordering communities. Other areas with heavy trade traffic with Southern Ontario include Montreal and much of Quebec, parts of northern Ohio and western Pennsylvania.
Southern Ontario is well known for its attractions and tourism. It is one of the most visited areas in the world. Some of the most popular tourist attractions are the CN Tower, Parliament Hill, Niagara Falls, National Gallery of Canada, Canada's Wonderland, CNE, Canadian War Museum, Toronto Zoo, Hockey Hall of Fame, Royal Canadian Mint, Marineland, The Rideau Canal, and the Royal Ontario Museum.
Niagara Falls is the 6th most visited attraction by domestic and international tourists in the world, with over 14 million tourists each year. Toronto is the 7th most visited city by international tourists in the world with over 6.6 million visitors per year. Ottawa is the most visited city in Canada by domestic tourists, hosting over 6.9 million Canadian visitors per year.
Southern Ontario is home to several professional sports teams, including the Toronto Blue Jays, Toronto Raptors, Toronto Maple Leafs, Ottawa Senators, Toronto FC, and three teams in the Canadian Football League. The region also hosts the Canadian Open (Golf) and Canadian Open (Tennis).
The area is home to many internationally renowned festivals and events including Toronto International Film Festival, Winterlude, Caribana, Bluesfest, Pride Week, Kitchener Oktoberfest, Havelock Jamboree, Toronto Indy, Sarnia Bayfest, Canada Day in Ottawa, International Freedom Festival in Windsor, Stratford Shakespeare Festival, and Virgin Festival.
Several large legal gambling establishments have been built throughout the Province with Caesars Windsor and Fallsview Casino being the two flagship casinos in the Province. In addition to casinos Ontario has many legal horse racing facilities with slot machines. Racetrack slots are located throughout the Province. All gaming in the Province is overseen by the Ontario Lottery and Gaming Corporation (OLG), and the Alcohol and Gaming Commission of Ontario.
Southern Ontario has many beautiful natural attractions as well. Wasaga Beach, Grand Bend, and Sandbanks, are amongst the nicest beaches on the Great Lakes. The Niagara Escarpment offers hiking, skiing, and hundreds of waterfalls including Niagara Falls. The Ottawa River has world class white water rafting which attracts rafters and kayakers from all over the globe. The region has some of North America's nicest parks. Ontario Parks governs all Provincial Parks, and Parks Canada governs all National Parks in the province.
Southern Ontario is home to both Canada's largest city and its capital city. Toronto is the capital of Ontario, as well as Canada's largest, and North America's fifth largest city. It has a population of 2,503,281, and a metropolitan population of over 5.5 million as of 2009. Ottawa is Canada's fourth largest city and capital city. It is home to most federal government departments and the Parliament of Canada. It has a population of 812,129, and a metropolitan population of over 1.4 million.
Southern Ontario communities have eight telephone area codes, 226, 289, 416, 519, 613, 647, 705, and 905, and 343 (2010).
Southern Ontario's Largest CMA's Template:See also Statistics Canada's measure of a metro area, the Census Metropolitan Area (CMA), roughly bundles together population figures from the core municipality with those from commuter municipalities.  Note: A city's Metropolitan area may actually be larger than its CMA. For example many consider Oshawa part of the Greater Toronto Area, however it is considered its own CMA.
|Southern Ontario Cities ( Not all CMA's listed )||2006||2001|
|St. Catharines–Niagara CMA||390,317||377,009|
Historically, Southern Ontario has been defined from its northern counterpart by counties. Southern Ontario has 38 census divisions, which at one point in time were all counties. Unlike the counties of the south, Northern Ontario has districts. Therefore the boundary between Southern and Northern Ontario has historically been the county and district division. Template:Citation needed Over time some of the larger counties in Ontario have become single tier governments and abandoned the county title. Below is a list of all counties, single-tier municipalities, and regional municipalities in the area, and their population at the 2006 census.Template:Col-4
- Brant (125,099)
- Bruce (65,349)
- Chatham-Kent (108,589)
- Dufferin (54,436)
- Durham (561,258)
- Elgin (85,351)
- Essex (393,402)
- Frontenac (143,865)
- Grey (92,411)
- Haldimand (45,212)
- Haliburton (16,147)
- Halton (439,256)
- Hamilton (504,559)
- Hastings (130,474)
- Huron (59,325)
- Kawartha Lakes (74,561)
- Lambton (128,204)
- Lanark (63,785)
- Leeds & Grenville (99,206)
- Lennox & Addington (40,542)
- Middlesex (422,333)
- Niagara (427,421)
- Northumberland (80,963)
- Norfolk (62,562)
- Oxford (102,756)
- Ottawa (812,129)
- Peel (1,159,405)
- Perth (74,344)
- Peterborough (133,080)
- Prescott and Russell (80,184)
- Prince Edward (25,496)
- Renfrew (97,545)
- Simcoe (422,204)
- Stormont, Dundas and Glengary (110,399)
- Toronto (2,503,281)
- Waterloo (478,121)
- Wellington (200,425)
- York (892,712)
- Muskoka and Parry Sound Districts are commonly regarded as a transitional region between Southern and Northern Ontario and may be considered part of either Southern Ontario or Northern Ontario in different contexts.
- Craig S. Campbell, "Rust Belt," in The American Midwest: An Interpretive Encyclopedia, eds. Richard Sisson, Christian Zacher, and Andrew Cayton, Indiana University Press, 2007, p. 78.
- Statistics Canada Population and dwelling counts, for Canada, provinces and territories, census metropolitan areas and census agglomerations, 2006 and 2001 censuses - 100% data. Statistics Canada (2008-11-05). Retrieved on 2009-04-01.