The Regional Municipality of Niagara, also colloquially known as the Niagara Region or Region of Niagara, is a regional municipality comprising twelve municipalities of Southern Ontario, Canada. The regional seat is in Thorold. It is the southern end of the Golden Horseshoe, the largest megalopolis in Canada.

Thorold is a city in Ontario, Canada, located on the Niagara Escarpment. It is also the seat of the Regional Municipality of Niagara. The Welland Canal passes through the city, featuring lock 7 and the Twin Flight Locks.