Simcoe District" was established in 1843 by the Legislature of Upper Canada.  Today, the Corporation of the County of Simcoe is comprised of sixteen towns and townships.  

The County has an estimated population of 465,000 people and is the second largest County based upon population and third largest based upon physical size? in Ontario. ?

As an "upper tier" municipality, the County of Simcoe is responsible for a range of municipal services which include social housing, land ambulance and emergency planning, environmental services (solid waste management), a County road system, Ontario Works, children's services, homes for the aged, a library co-operative, museum, archives, County forest management, tourism, a Geographic Information System (computer mapping), and land use policy planning.

The local, or "lower tier" municipalities are responsible for water and sewer services, local roads, public libraries, recreation services, fire and police services, land use development control, licensing, and permitting services.?

The cities of Barrie and Orillia, although separate politically and administratively from the County, are geographically and economically part of the County.  The County of Simcoe provides services such as long term care, social services, and social housing to residents of the cities and the cities participate in funding for the archives and museum. City representatives serve on the County committees that oversee matters that relate to these departments.?