The Township was established in as part of what was then York County. Whitby Township was one of five townships along Lake Ontario named for towns in northeast England (York, Scarborough, Pickering, Whitby and Darlington). In 1852, the Township became part of the newly-formed County of Ontario. In 1855, the Town of Whitby was incorporated as a separate municipality in the southern portion of the Township and in 1858, the Township of East Whitby was formed from the eastern portion of the municipality near Oshawa.