Cheapest return flights from St. Louis to Toronto in September from $330

AirHint found the following cheapest return flights from St. Louis (STL) to Toronto (YYZ) in September 2025 (see full year).

Return flights

17 Sep - 20 Sep American Airlines
11 Sep - 20 Sep Delta
17 Sep - 20 Sep Air Canada direct

Also check the deals for one-way flights from St. Louis to Toronto in September.

Skyscanner

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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