The Town of Whitby was incorporated in 1855, three years after it was chosen as the seat of government for the newly formed County of Ontario. Although settlement dates back to 1800, it was not until 1836 that a downtown business centre was established by Whitby's founder Peter Perry.

Whitby's chief asset was its fine natural harbour on Lake Ontario, from which grain from the farmland to the north was first shipped in 1833. In the 1840s a road was built from Whitby Harbour to Lake Simcoe and Georgian Bay to bring trade and settlement through the harbour to and from the rich hinterland to the north. In the 1870s a railway was constructed to Port Perry and Lindsay from Whitby Harbour.

Whitby is also the site of Trafalgar Castle School, a private girls' school founded in 1874. The building, constructed as an Elizabethan-style castle in 1859–62 as a private residence for the Sheriff of Ontario County, is a significant architectural landmark and Whitby's only Provincial historic site marked with a plaque. The school celebrated its 125th anniversary in 1999.

During the Second World War, Whitby was the location of Camp X, a secret spy training facility established by Sir William Stephenson, the "Man Called Intrepid". Although the buildings have since been demolished, a monument was unveiled on the site of Camp X in 1984 by Ontario's Lieutenant-Governor John Black Aird.

Whitby's most famous sporting team is the Whitby Dunlops, a celebrated ice hockey squad that captured the world championship in 1958 at Oslo, Norway. This team featured long-time president of the Boston Bruins, Harry Sinden. Furthermore, Whitby is home to Olympic Medalists, and NHL players Adam Foote, and Joe Nieuwendyk. It is also the home of Gary Roberts who can be seen at the Brooklin Spring Fair, almost ever year. (Brooklin is a part of Whitby, it is north of Taunton road, around the Winchester area).

Today, Whitby is the seat of government in Durham Region, and the regional government is the town's largest employer. Also located in the town is the Whity Psychiatric Hospital, a large mental health centre.

It is commonly considered part of the Greater Toronto Area, although for census purposes it belongs to the greater Oshawa Metropolitan Area. They are both in the eastern part of the Golden Horseshoe region. As is the case with Oshawa, several major manufacturing businesses are located in Whitby.

Whitby Township (now the Town of Whitby) was named after the seaport town of Whitby, Yorkshire, England. When the township was originally surveyed in 1792, the surveyor, from the northern part of England, named the townships east of Toronto after towns on England's northeastern coast: York, Scarborough, Pickering, Whitby and Darlington. The name "Whitby" is Danish, dating from about 867 CE when the Danes invaded Britain. It is a contraction of "Whitteby," meaning "White Village." The allusion may be to the white lighthouse on the pier at Whitby, Yorkshire, and also at Whitby, Ontario.' (Whitby is known as White-by by many of the youth, commenting on the social make-up of racial traits which seems to be swiftly changing like both Pickering and Ajax have done before it.)

In addition to Whitby, Yorshire, the Town of Whitby is also officially twinned with Longueuil, Quebec and Feldkirch, Austria

Whitby is also home to the Iroquois Sports Complex, one of the largest minor sports centres in North America. Whitby also developed the McKinney Sports complex which boasts 3 ice pads, and Luther Vipond Arena in Brooklin with one.

Whitby is subdivided into sections. North of Taunton Road is the Village of Brooklin and North of Brooklin is Myrtle and Myrtle station.

Visit their website at www.town.whitby.on.ca