Durham Regional Municipality, also called Durham Region (2003 population 525,000), is a regional political area located east of Toronto, Ontario. It has an area of approximately 2,500 square kilometers and includes the municipalities of Pickering, Ajax, Oshawa, Whitby, Clarington, Uxbridge Township, Scugog Township and Brock Township. Durham Region is considered part of the Greater Toronto Area. The regional seat is in Whitby.

Durham Region was established in 1974 as one of several new "regional" governments in the Province of Ontario, primarily around fast growing Toronto. Durham Region encompasses areas that were previously part of Ontario County and Durham County.

The southern portion of the region, adjacent to Lake Ontario is primarily urban in nature, and is essentially part of Toronto's extended suburbs. The northern area encompasses rural areas and small towns.

Major employers include General Motors of Canada , Ontario Power Generation, Lakeridge Health System , Durham College, University of Ontario Institute of Technology and many smaller component and transportation firms supplying the automotive industry.

The Canadian headquarters of General Motors, Volkswagen, and BMW are all located in the region. The automotive industry is especially concentrated in Oshawa.

The four separate public transit systems in the region, operated by various municipalities, are set to be amalgamated under the Region's administration at the beginning of 2006.

Durham also has one indian reserve, Mississaugas of Scugog Island