List of Ontario separated municipalities

In the Canadian province of Ontario, municipalities operate in various hierarchies. Though most originated from a two-tier arrangement of a county containing smaller divisions, there are now single-tier cities made entirely of former counties, regional municipalities, and other arrangements, all under the direction of the provincial government.

One arrangement which is becoming more common is to separate larger, denser towns and cities from their more rural counties and regions. While they no longer share in the administration of the wider area, relationships are usually maintained as civic offices and other infrastructure may remain within the boundaries of the separated town.

Unlike a single-tier municipality or a region, a separated municipality does not form its own separate census division, but remains a census subdivision of the county. Hence, its separation from the county is strictly administrative.

The following list shows those municipalities which are separated, and the counties in which they were once part.

Owen Sound was separated from Grey County for almost 100 years, but re-joined the county in 2002. As a result, it is no longer a separated municipality.

A historic case that predates this trend by some time was the split of York County in 1954. The southernmost section became Metropolitan Toronto (now the city of Toronto), the remainder eventually became York Region; however, Toronto was considered a separate census division while the above municipalities are still considered to be within the census division they are separated from. Other former separated municipalities include Hamilton and St. Catharines, which re-joined their county upon its re-incorporation as a regional municipality.

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