Northumberland County, Ontario

Northumberland County is situated on the north shore of Lake Ontario, in central Ontario, Canada. It is located east of the Regional Municipality of Durham (formerly Durham County), west of Hastings County, southeast of Kawartha Lakes and south of Peterborough County. The county seat is Cobourg. Together with Durham County, it formed the Newcastle District from 1802 to 1849 and the United Counties of Northumberland and Durham from 1850 to 1973. Effective January 1, 1974, part of Durham County was merged with Ontario County to create the Regional Municipality of Durham. At that time, Northumberland reverted to a standalone county.

It was first aggressively settled by United Empire Loyalists fleeing the former 13 British American Colonies in the late 18th century. The Crown provided plots to the settlers for nominal sums (with the stipulation of making the land productive in a set number of years) or free to those who had served against the American Colonial Army. Following the War of 1812, many port towns, Port Hope and Cobourg in particular, became important centres for commercial activity and a landing point for European immigrants arriving on steamers.

Subdivisions
Northumberland County consists of seven municipalities:
 * Municipality (town) of Brighton
 * Town of Cobourg
 * Municipality of Port Hope - originally part of Durham County
 * Municipality (town) of Trent Hills
 * Township of Alnwick/Haldimand
 * Township of Cramahe
 * Township of Hamilton

The Alderville First Nation is within the Northumberland census division but is independent of county administration.

Demographics
The numbers below are for the Northumberland census division and combine Northumberland County and the Alderville First Nation reserve.

Historic populations:
 * Population in 2001: 77,497
 * Population in 1996: 74,437 (adjusted to 2001 boundaries)

Towns/Villages

 * Cobourg, Ontario
 * Port Hope, Ontario
 * Brighton, Ontario
 * Campbellford, Ontario
 * Colborne, Ontario
 * Hastings, Ontario
 * Baltimore, Ontario
 * Bewdley, Ontario
 * Camborne, Ontario
 * Centreton, Ontario
 * Grafton, Ontario
 * Warkworth, Ontario

The County also includes seven smaller communities which serve as postal addresses: Campbellcroft, Gore’s Landing, Harwood, Roseneath, Castleton, Codrington, and Trent River.