Durham (formerly known as Clarington—Scugog—Uxbridge) is a federal electoral district in Ontario, Canada, that has been represented in the House of Commons of Canada from 1904 to 1968, and since 1988.

Its first iteration was created in 1903 from Durham East and Durham West ridings. It consisted of the county of Durham.

The electoral district was abolished in 1966 when it was merged into Northumberland—Durham ridings.

It was recreated in 1987 from parts of Durham—Northumberland and Ontario ridings.

The second incarnation of the riding was initially defined to consist of the Town of Newcastle, the townships of Scugog and Uxbridge, Scugog Indian Reserve No. 34, the part of the City of Oshawa lying north of Rossland Road and the allowance for road in front of lots 1, 2, 3 and 4, Concession 3, and the part of the Town of Whitby lying north of Taunton Road.

In 1996, it was redefined to consist of the Township of Scugog, Scugog Indian Reserve No. 34, the Town of Clarington, and the part of the City of Oshawa lying north of a line drawn from west to east along Taunton Road, south along Ritson Road North, east along Rossland Road East, south along Harmony Road North, and east along King Street East.

The electoral district was abolished in 2003 when it was redistributed between Clarington—Scugog—Uxbridge, Oshawa and Whitby—Oshawa ridings.

Clarington—Scugog—Uxbridge was defined to consist of the townships of Uxbridge and Scugog, the Municipality of Clarington, and the Mississaugas of Scugog Island reserve. In 2004, "Clarington—Scugog—Uxbridge" was renamed "Durham" riding.

Following the Canadian federal electoral redistribution, 2012, this riding lost territory to Pickering—Uxbridge and Northumberland—Peterborough South, and gained territory from Oshawa and Whitby—Oshawa during the 2012 electoral redistribution.

...
Wikipedia