The riding was adjusted by the 2015 Representation Act for the 2018 provincial election,[2] losing some territory to the district of Oshawa,[3] and replaced as the district of Whitby.

[4] The provincial electoral district was created from the same ridings in 2007.

It consists of the Town of Whitby and northwestern section of the City of Oshawa (specifically, the portion of the city lying north and west of a line drawn from the western city limit east along King Street West, north along the Oshawa Creek, east along Rossland Road West, north along Simcoe Street North, and east along Winchester Road East to the eastern city limit).

For the 2018 election, Whitby-Oshawa was re-districted as Whitby to more closely correspond to the actual town's borders.

According to the 2011 Canadian census ^ Change is from redistributed results.