The Thousand Islands Parkway (often written as 1000 Islands Parkway) is a scenic parkway in the Canadian province of Ontario. It extends easterly from an interchange with Highway 401 in Gananoque for approximately 40 kilometres (25 mi) to rejoin Highway 401 near the community of Butternut Bay, west of Brockville. The parkway follows the north shore of the St. Lawrence River, and was formerly designated Highway 2S (S for Scenic) until 1970. It passes through the communities of Gray's Beach, Halsteads Bay, Ivy Lea, Darlingside, Rockport, Narrows, La Rue Mills and Mallorytown Landing, as well as providing access to the three inland properties of the Thousand Islands National Park. Highway 137, which meets the parkway near its midpoint, provides access to the Interstate 81 in New York via the Thousand Islands Bridge.

King's Highway 401, commonly referred to as Highway 401 and also known by its official name as the Macdonald–Cartier Freeway or colloquially referred to as the four-oh-one, is a controlled-access 400-series highway in the Canadian province of Ontario. It stretches 828 kilometres (514 mi) from Windsor in the west to the Ontario–Quebec border in the east. The part of Highway 401 that passes through Toronto is North America's busiest highway, and one of the widest. Together with Quebec Autoroute 20, it forms the road transportation backbone of the Quebec City–Windsor Corridor, along which over half of Canada's population resides. It is also a Core Route in the National Highway System of Canada. The route is maintained by the Ministry of Transportation of Ontario (MTO) and patrolled by the Ontario Provincial Police. The speed limit is 100 km/h (62 mph) throughout its length, with the only exceptions being the posted 80 km/h (50 mph) limit westbound in Windsor and in most construction zones, along with a 110 km/h (68 mph) speed limit between Windsor and Tilbury.