After World War II, southern Ontario's major urban centres began rapidly increasing in population and physical area. Towns became cities, cities joined to form metropolitan governments and, in many areas, outlying suburbs merged into a continuous cityscape. As a result town, township, and county administrations outgrew their traditional boundaries and powers. A new level of administration was needed to supply urban services over a much larger area.
While the first regional municipality was formed in 1953, most were created in the late 1960's and early 1970's gradually replacing Ontario's more heavily populated counties. Administratively, regional municipalities usually have more powers than counties regarding issues such as land-use planning, social services and major roads. In most cases they have the same borders as the counties they replaced, however some counties have been merged, split or renamed.
Several townships ceased to exist or were transferred to neighbouring counties and regional municipalities when the changes took place. Consult the annual Municipal Directory (published by the Ontario Municipal Association) for information about these changes as well as changes that have affected local municipalities since the beginning of the 20th century. It can be consulted at the Archives of Ontario and in most Ontario libraries.
Since the mid-1990's, as a result of further municipal restructuring, some of the regional municipalities have ceased to exist. Also, some counties and regional municipalities merged with the municipalities included within them. Click here for information on these changes.
See the table below for information on changes to counties and districts between 1953 and the 1990's; click on the links in the table to view maps of counties or regional municipalities:
County/District | Changes | Year |
---|---|---|
Carleton County |
Replaced by the Regional Municipality of Ottawa-Carleton |
1968 |
Durham County |
Southern part replaced by the Regional Municipality of Durham Manvers Township transferred to Victoria County Cavan Township transferred to Peterborough County |
1973 |
Haldimand County |
Replaced by the Regional Municipality of Haldimand-Norfolk (re-instated as a county in 2001) |
1974 |
Halton County |
Replaced by the Regional Municipality of Halton |
1973 |
Lincoln County |
Replaced by the Regional Municipality of Niagara |
1970 |
Muskoka District |
Replaced by the District Municipality of Muskoka |
1971 |
Norfolk County |
Replaced by the Regional Municipality of Haldimand-Norfolk (re-instated as a county in 2001) |
1974 |
United Counties of Northumberland and Durham. |
With the creation of the Regional Municipality of Durham, Northumberland became a standalone county. South Monaghan Township transferred to Peterborough County |
1973 |
Ontario County |
South part transferred to the Regional Municipality of Durham Rama and Mara Townships transferred to Simcoe County |
1973 |
Peel County |
Replaced by the Regional Municipality of Peel |
1973 |
Sudbury District |
Part transferred to the new Regional Municipality of Sudbury |
1973 |
Replaced by the Regional Municipality of Waterloo |
1972 |
|
Replaced by the Regional Municipality of Niagara |
1970 |
|
Replaced by the Regional Municipality of Hamilton-Wentworth |
1973 |
|
South part transferred to the Municipality of Metropolitan Toronto North part replaced by the Regional Municipality of York |
1953 1971 |
The Changing Shape of Ontario Home | Ontario's boundaries 1774-1912 | Early Districts and Counties
Districts of Northern Ontario | Post-World War II Regional Municipal Governments
Maps of Southern Ontario circa 1951 by County | Maps of Southern Ontario circa 1951 by Geographical Location
Municipal Restructuring since 1996 | Sources of Information