|Dissolved||1850 (reorganized into the United Counties of Northumberland and Durham)|
|Time zone||UTC-5 (Eastern (EST))|
|• Summer (DST)||UTC-4 (Eastern (EDT))|
Durham County (area 376,397 acres (1,523 km2)) is a historic county in Ontario, Canada. It was named for the English County Durham and city of Durham. The County was created in 1792 although was later merged Northumberland County to form the United Counties of Northumberland and Durham. In 1974, the two counties were split and reorganized, with the former portions of Durham County reorganized into the Regional Municipality of Durham.
Durham County was created in 1792 by a proclamation of Lieutenant Governor Simcoe. The original boundaries were as follows:
In 1798, the Parliament of Upper Canada passed a statute defining the boundaries of the counties. Durham was then defined to include:
In 1834, the townships of Verulam, Fenelon and Eldon were added to Durham County.
Mergers and dissolution
Effective January 1, 1974, about half of Durham County was merged with Ontario County to create the Regional Municipality of Durham. The township of Manvers was transferred to Victoria County, which is now the city of Kawartha Lakes, Cavan was transferred to Peterborough County, where it is now part of Cavan-Monaghan, and Hope was transferred to Northumberland County, where it is now part of the town of Port Hope.
The townships of Darlington and Clarke were amalgamated with the Town of Bowmanville and the Village of Newcastle as the Town of Newcastle, and the township of Cartwright was combined with the Ontario County townships of Scugog and Reach to create a new Township of Scugog. In 1993, Newcastle was renamed Clarington.
- Cartwright – Area 37,600 acres (152 km2). Located in the northwest portion of Durham County, touching Lake Scugog. The Township was opened in 1816. The name is in honour of Richard Cartwright. Mostly settled between 1850 and 1858 by Irish immigrants. Community centres: Purple Hill, Caesarea, Scugog. This Township is now in Scugog Township
- Cavan – Area 62,296 acres. Settled in 1816. Community centres : Millbrook, Cavan and Carmel. This Township is now in Cavan-Monaghan Township in Peterborough County
- Clarke - Area, 68,500 acres (277 km2). Was opened in 1792 and named in honour of General Alured Clarke. Community centres: Newcastle, Newtonville, Crooked Creek, Morgan's Corners, Orono, Kendall, Leskard. This Township is now in Clarington Municipality
- Darlington – Area, 68,907 acres (279 km2). It was opened in 1792 and named after the ancient English town. The first European settlers arrived from the United States in 1794. Community centres, Bowmanville, Enniskillen, Tyrone, Courtice. (the settlement was mostly Irish). This Township is now in Clarington Municipality.
- Hope – Area, 62,959 acres (255 km2). First settlement was in the town of Port Hope. The Township as opened in 1792 and named in honour Colonel Henry Hope, a member of the Legislative Council of Canada. The Township is now the Town of Port Hope in Northumberland County
- Manvers – Area 69,923 acres (283 km2). Opened in 1816. Named in honour of Charles Pierrepont, 1st Earl Manvers. Community centres: Pontypool, Manvers Station, Janetville, Yelverton, Bethany, Franklin, Brunswick, Burton, Ballyduff, Lotus, Fleetwood, Lifford. Now in the City of Kawartha Lakes.
- Proclamation, Lieutenant Governor Simcoe, July 16, 1792; reprinted Statutes of the Province of Upper Canada; Together with Such British Statutes, Ordinances of Quebec, and Proclamations, as Relate to the Said Province (Kingston: F. M. Hill., 1831) p. 24.
- An act for the better division of this province, SUC 1798, c. 5, s. 20. Reprinted in The Statutes of Upper Canada to the Time of Union, Revised and Published by Authority, Vol. I - Public Acts (Toronto: Robert Stanton, Queen's Printer, 1843).
- An Act to attach certain Townships in the District of Newcastle to the Counties of Northumberland and Durham, respectively, SUC 1834, c. 15.
- Jesse Edgar Middletwon and Fred Landon, Province of Ontario — A History 1615 to 1927 (Toronto: Dominion Publishing Company, 1927).
- "The First Settlers in Clarington - Canadian History in the Making", Clarington Promoter, Volume 7 Issue 3 November 2017.
- Sherrell Branton Leetooze, The Trail Through The Bush — A brief history of Manvers Township (Durham: L.M-J Associates, 1998).