Newmarket (2021 population: 87,942) is a town and regional seat of the Regional Municipality of York in the Canadian province of Ontario. It is part of Greater Toronto in the Golden Horseshoe region of Southern Ontario. The name stems from the fact that the settlement was a "New Market", in contrast to York as the Old Market.
The town was formed as one of many farming communities in the area, but also developed an industrial centre on the Northern Railway of Canada's mainline, which was built in 1853 through what would become the downtown area. It also became a thriving market town with the arrival of the Metropolitan Street Railway in 1899. Over time, the town developed into a primarily residential area, and the expansion of Ontario Highway 400 to the west and the construction of Ontario Highway 404 to the east increasingly turned it into a bedroom town since the 1980s.