Northumberland County is situated along the north shore of Lake Ontario and the south shore of Rice Lake. It is located in the eastern tip of Ontario's Greater Golden Horseshoe. Named for its geographical distinction, the Greater Golden Horseshoe is the most populous region in Canada, with a population of 8.1 million, it makes up slightly more than a quarter (25.6%) of Canada's total population. Only one hour east of Toronto, Northumberland County is easily accessed from the 401 highway. The proximity to this huge urban market makes Northumberland County among the most ideal service and distribution locations in the country.
Northumberland County has a population of 80,963, an increase of 4.47% from 2001. This percentage is slightly behind Ontario's average population increase of 6.58%. (Lifted from Northumberland County Agriculture Action Plan)
The county is composed of the following local municipalities: