The Queen Elizabeth Way (QEW) is a 400-series highway in the Canadian province of Ontario linking Toronto with the Niagara Peninsula and Buffalo, New York. The freeway begins at the Peace Bridge in Fort Erie and travels 139.1 kilometres (86.4 mi) around the western end of Lake Ontario, ending at Highway 427 as the physical highway continues as the Gardiner Expressway into downtown Toronto. The QEW is one of Ontario's busiest highways, with an average of close to 200,000 vehicles per day on some sections. Major highway junctions are at Highway 420 in Niagara Falls, Highway 405 in Niagara-on-the-Lake, Highway 406 in St. Catharines, the Red Hill Valley Parkway in Hamilton, Highway 403 and Highway 407 in Burlington, Highway 403 at the Oakville–Mississauga boundary, and Highway 427 in Etobicoke. Within the Regional Municipality of Halton the QEW is signed concurrently with Highway 403. The speed limit is 100 km/h (62 mph) throughout most of its length, with the exceptions being between Hamilton and St. Catharines where the posted limit is 110 km/h (68 mph).

The Niagara Peninsula is an area of land lying between the southwestern shore of Lake Ontario and the northeastern shore of Lake Erie, in Ontario, Canada. Technically an isthmus rather than a peninsula, it stretches from the Niagara River in the east to Hamilton, Ontario, in the west. The peninsula is located in the Golden Horseshoe region of Southern Ontario, and has a population of roughly 1,000,000 residents. The region directly across the Niagara River and Lake Erie in New York State is known as the Niagara Frontier.