(For reference, the Canadian House of Commons, according to Wikipedia's footer, divides into 158 Liberals, 119 Conservatives, 33 Québécois, 25 New Democrats, 2 Greens, and 1 Independent.
The Senate divides into 41 Independents, 20 Conservatives, 12 Canadians, 12 Progressives, and 8 non-affiliated, which last category raises interesting questions about the meaning of "Independent".)
It's worth noting that the American two-party system is explicitly protected by many laws that grant special privileges to "the two largest parties" or some similar category; it doesn't rely on the electoral system at all. If other parties got equal treatment before the law, you might see more of them around.