I don't know why it's "Canadian", but Canadian bacon is a real thing and there are some various important differences between 'regular' bacon and the northen variety. In Canada, Canadian Bacon is called usually 'Back Bacon'.

'Regular' bacon is meat from the back and sides (rump and belly), then usually cut into thin strips. Canadian bacon however is taken from the leaner tender eye of the loin area of the hog, located in the middle of the back. It is then rolled, bound, salted and smoked so the end product is more like a small ham or large whole-meat sausage than traditional bacon.

In the United States places like pizza parlors will try to use ham with burnt edges and call it 'Canadian bacon', though happily many places are finally learning the distinction and using real Canadian bacon and listing ham as another topping altogether.