Clarington (2001 population 69,834) is a town on Lake Ontario east of Toronto, Ontario, Canada in the Durham Region. Gaining its present name in 1993 (it had been known as the Town of Newcastle from 1974-93), the town consists of several local communities, including Bowmanville, Newcastle, Courtice, and Orono.

The name "Clarington" is an amalgamation of the names of the two historical townships that made up the geographic area, "Clarke" and "Darlington"

Major employers in Clarington include the Darlington Nuclear Generating Station and several medium-to-large sized manufacturing businesses.

Clarington is part of the Greater Toronto Area.