A massive amount of buses in most North American cities are Canadian, as New Flyer, a company based in Winnipeg, dominates the bus market in a large number of North American cities.
“But my city uses Novabuses!”. Those are Canadian too, Novabus is based in Montreal.
When it comes to coaches, Canadians basically have a monopoly in North America. There’s two big coach makers, MCI, which is owned by the aforementioned New Flyer, and Prevost Car, founded in Quebec (although Prevost is owned by Volvo these days).