Southwestern Ontario is a subregion of Southern Ontario in the Canadian province of Ontario, centred on the city of London. It extends north to south from the Bruce Peninsula on Lake Huron to the Lake Erie shoreline, and east to south-west roughly from Guelph to Windsor. The region had a population of 2,504,878 in 2011. Other significant towns and cities in the region are Brantford, Cambridge, Chatham, Goderich, Ingersoll, Kitchener, Owen Sound, Sarnia, St.