How does KAYAK find such low prices on flights from Ontario to St. Louis?

KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ontario to St. Louis.

How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Ontario to St. Louis?

KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Louis from Ontario is likely to change within 7 days, so travelers know whether to wait or book now.

What is the Hacker Fare option on flights from Ontario to St. Louis?

Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Louis with an airline and back to Ontario with another airline.

What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Ontario to St. Louis?

Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Louis from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

C$ 244 CHEAP FLIGHTS from Ontario to St. Louis

Save 21% or more on flights. Compare deals from all over the web.

Never overpay with our price tracking tools.

Filter searches by price, airline and more to find your best flights.

Flight Deals

Cheap Flights from Ontario to St. Louis

Discover the best prices for you by selecting your travel dates on KAYAK.

Round-trip

One-way

Last minute

Direct

Recent round-trip flight deals from Ontario to St. Louis

Mon, 26 Oct - Mon, 2 Nov

3:14 p.m. - 12:19 a.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

10h 05m1 stop Chicago O'Hare Intl

6:00 a.m. - 2:34 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

7h 34m1 stop Chicago O'Hare Intl

C$ 447American Airlines

Tue, 20 Oct - Tue, 27 Oct

7:29 a.m. - 4:53 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

10h 24m1 stop Chicago O'Hare Intl

7:28 a.m. - 5:44 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

9h 16m1 stop Chicago O'Hare Intl

C$ 447American Airlines

Thu, 19 Nov - Thu, 26 Nov

1:16 p.m. - 8:04 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

7h 48m1 stop Chicago O'Hare Intl

7:16 a.m. - 5:40 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

9h 24m1 stop Chicago O'Hare Intl

C$ 463American Airlines

Thu, 29 Oct - Sat, 31 Oct

1:15 p.m. - 8:57 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

8h 42m1 stop Chicago O'Hare Intl

5:00 a.m. - 2:33 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

8h 33m1 stop Chicago O'Hare Intl

C$ 463American Airlines

Tue, 6 Oct - Wed, 7 Oct

2:00 p.m. - 9:21 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

8h 21m1 stop Chicago O'Hare Intl

1:29 p.m. - 11:26 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

8h 57m1 stop Chicago O'Hare Intl

C$ 661United Airlines

Thu, 29 Oct - Thu, 5 Nov

2:10 p.m. - 3:23 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 13mdirect

4:05 p.m. - 7:05 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

2h 00mdirect

C$ 686Air Canada

Tue, 6 Oct - Thu, 8 Oct

12:55 p.m. - 2:00 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

8:55 a.m. - 11:49 a.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 717Air Canada

Tue, 6 Oct - Thu, 8 Oct

12:05 p.m. - 6:41 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

7h 36m2 stops Ottawa Montreal Pierre Elliott Trudeau Intl

8:55 a.m. - 11:49 a.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 717Air Canada

Thu, 22 Oct - Sun, 25 Oct

6:00 a.m. - 9:21 p.m.YOW Ottawa-STL Lambert-St Louis

16h 21m3 stops Washington, D.C. Dulles Intl Indianapolis Chicago O'Hare Intl

6:50 p.m. - 1:11 p.m.STL Lambert-St Louis-YOW Ottawa

17h 21m2 stops Chicago O'Hare Intl Newark

C$ 727United Airlines

Thu, 22 Oct - Sun, 25 Oct

6:05 a.m. - 9:21 p.m.YOW Ottawa-STL Lambert-St Louis

16h 16m2 stops Newark Chicago O'Hare Intl

6:50 p.m. - 1:11 p.m.STL Lambert-St Louis-YOW Ottawa

17h 21m2 stops Chicago O'Hare Intl Newark

C$ 727United Airlines

Recent last minute flight deals from Ontario to St. Louis

Mon, 21 Sep - Tue, 29 Sep

5:57 p.m. - 11:38 p.m.YOW Ottawa-STL Lambert-St Louis

6h 41m1 stop Newark

9:30 a.m. - 4:38 p.m.STL Lambert-St Louis-YOW Ottawa

6h 08m1 stop Newark

C$ 807United Airlines

Mon, 21 Sep - Tue, 29 Sep

6:25 a.m. - 12:02 p.m.YOW Ottawa-STL Lambert-St Louis

6h 37m1 stop Chicago O'Hare Intl

3:11 p.m. - 11:54 p.m.STL Lambert-St Louis-YOW Ottawa

7h 43m2 stops Chicago O'Hare Intl Washington, D.C. Dulles Intl

C$ 807United Airlines

Mon, 21 Sep - Mon, 28 Sep

6:25 a.m. - 12:02 p.m.YOW Ottawa-STL Lambert-St Louis

6h 37m1 stop Chicago O'Hare Intl

9:30 a.m. - 4:38 p.m.STL Lambert-St Louis-YOW Ottawa

6h 08m1 stop Newark

C$ 807United Airlines

Mon, 21 Sep - Fri, 2 Oct

6:00 a.m. - 10:59 p.m.YOW Ottawa-STL Lambert-St Louis

17h 59m3 stops Washington, D.C. Dulles Intl Indianapolis Chicago O'Hare Intl

8:00 a.m. - 5:16 p.m.STL Lambert-St Louis-YOW Ottawa

8h 16m1 stop Chicago O'Hare Intl

C$ 807United Airlines

Sat, 19 Sep - Sat, 26 Sep

12:55 p.m. - 2:00 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

8:55 a.m. - 11:49 a.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 829Air Canada

Mon, 21 Sep - Fri, 2 Oct

5:27 p.m. - 9:24 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

4h 57m1 stop Washington, D.C. Reagan-National

6:00 a.m. - 11:59 a.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

4h 59m1 stop Washington, D.C. Reagan-National

C$ 836American Airlines

Mon, 21 Sep - Tue, 29 Sep

7:00 p.m. - 11:38 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

5h 38m1 stop Newark

2:40 p.m. - 5:34 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 836Multiple Airlines

Sat, 19 Sep - Sat, 26 Sep

7:55 a.m. - 4:52 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

9h 57m1 stop New York LaGuardia

5:47 p.m. - 11:13 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

4h 26m1 stop Minneapolis St Paul

C$ 838Delta

Sat, 19 Sep - Sat, 26 Sep

12:55 p.m. - 2:00 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

12:10 p.m. - 6:53 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

5h 43m1 stop Montreal Pierre Elliott Trudeau Intl

C$ 842Air Canada

Sat, 19 Sep - Sun, 20 Sep

12:55 p.m. - 2:00 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

8:55 a.m. - 11:49 a.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 914Air Canada

Recent direct flight deals from Ontario to St. Louis

Thu, 29 Oct - Thu, 5 Nov

2:10 p.m. - 3:23 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 13mdirect

4:05 p.m. - 7:05 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

2h 00mdirect

C$ 686Air Canada

Tue, 6 Oct - Thu, 8 Oct

12:55 p.m. - 2:00 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

8:55 a.m. - 11:49 a.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 717Air Canada

Fri, 30 Oct - Fri, 6 Nov

2:10 p.m. - 3:23 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 13mdirect

4:05 p.m. - 7:05 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

2h 00mdirect

C$ 736Air Canada

Sat, 10 Oct - Mon, 12 Oct

7:15 p.m. - 8:20 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

8:55 a.m. - 11:49 a.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 736Air Canada

Wed, 14 Oct - Wed, 21 Oct

7:15 p.m. - 8:20 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

2:40 p.m. - 5:34 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 739Air Canada

Tue, 13 Oct - Mon, 19 Oct

12:55 p.m. - 2:00 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

2:40 p.m. - 5:34 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 739Air Canada

Wed, 30 Sep - Tue, 6 Oct

7:15 p.m. - 8:20 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

8:55 a.m. - 11:49 a.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 739Air Canada

Thu, 29 Oct - Tue, 3 Nov

2:10 p.m. - 3:23 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 13mdirect

4:05 p.m. - 7:05 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

2h 00mdirect

C$ 739Air Canada

Tue, 13 Oct - Tue, 20 Oct

4:55 p.m. - 6:41 p.m.YUL Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis

2h 46mdirect

12:10 p.m. - 3:41 p.m.STL Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl

2h 31mdirect

C$ 877United Airlines

Thu, 22 Oct - Mon, 26 Oct

12:55 p.m. - 2:00 p.m.YYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mdirect

4:05 p.m. - 6:59 p.m.STL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mdirect

C$ 1,027United Airlines

Useful Info

Low season	April
High season	October
Cheapest flight	C$ 244

Best time to beat the crowds but there is an average 25% increase in price.

Most popular time to fly and prices are also 10% lower on average.

Flight from Toronto to St. Louis

How does KAYAK find such low prices on flights from Ontario to St. Louis?
KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ontario to St. Louis.
How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Ontario to St. Louis?
KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Louis from Ontario is likely to change within 7 days, so travelers know whether to wait or book now.
What is the Hacker Fare option on flights from Ontario to St. Louis?
Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Louis with an airline and back to Ontario with another airline.
What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Ontario to St. Louis?
Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Louis from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.