York County, Ontario
York County is a historic county in the Canadian province of Ontario.
York County was created in 1792. It originally comprised all of what is now York Region, Peel Region, Halton Region, Toronto and parts of the current Durham Regional Municipality and the current city of Hamilton, Ontario.
In 1816, Wentworth County and Halton County were created from York County. In 1851, Ontario County and Peel County were separated from York.
In 1953, Metropolitan Toronto was separated from York County.
In 1971, the remaining portion of York County was replaced by the York Regional Municipality.
See also List of Ontario census divisions.