Steeles Avenue is an east–west street that forms the northern city limit of Toronto and the southern limit of York Region in Ontario, Canada. It stretches 77.3 km (48.0 mi) across the western and central Greater Toronto Area from Appleby Line in Milton in the west to the Toronto-Pickering city limits in the east, where it continues east into Durham Region as Taunton Road, which itself extends 58 km (36 mi) across the length of Durham Region to its boundary with Northumberland County.

Toronto is the most populous city in Canada and the capital city of the Canadian province of Ontario. With a population of 2,794,356 in 2021, it is the fourth-most populous city in North America. The city is the anchor of the Golden Horseshoe, an urban agglomeration of 9,765,188 people surrounding the western end of Lake Ontario, while the Greater Toronto Area proper had a 2021 population of 6,712,341. Toronto is an international centre of business, finance, arts, sports and culture and is one of the most multicultural and cosmopolitan cities in the world.