Find flights
Deals
When to book
FAQs

Cheap flights from Ontario to St. Louis from C$ 337

YYZ — STL
12 Dec — 19 Dec1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Ontario to St. Louis

Enter your travel dates to find the best prices.

Cheapest flights from Ontario to St. Louis

Wed 9/1210:40 a.m. -
2 stops49h 37m
Wed 16/126:20 p.m. -
1 stop18h 20m
Deal found 11/11C$ 556
Wed 2/128:00 a.m. -
1 stop13h 11m
Wed 9/126:20 p.m. -
1 stop21h 25m
Deal found 11/11C$ 646
Wed 9/1211:36 a.m. -
1 stop9h 22m
Wed 16/126:48 a.m. -
1 stop8h 42m
Deal found 10/11C$ 650
Mon 7/126:30 a.m. -
1 stop18h 42m
Mon 14/1212:02 p.m. -
2 stops26h 18m
Deal found 8/11C$ 653
Thu 3/126:30 a.m. -
1 stop18h 42m
Mon 7/1212:02 p.m. -
2 stops30h 37m
Deal found 7/11C$ 660
Sat 19/1211:45 a.m. -
1 stop13h 14m
Sat 16/15:05 a.m. -
1 stop11h 39m
Deal found 10/11C$ 673
Tue 1/1211:45 a.m. -
1 stop9h 05m
Fri 4/126:02 a.m. -
1 stop10h 41m
Deal found 9/11C$ 677
Mon 7/123:22 p.m. -
1 stop7h 55m
Mon 14/121:43 p.m. -
1 stop8h 58m
Deal found 8/11C$ 686
Tue 8/122:00 p.m. -
2 stops9h 59m
Wed 9/1210:50 a.m. -
2 stops7h 37m
Deal found 11/11C$ 848
Fri 4/126:00 a.m. -
2 stops13h 16m
Sun 6/126:10 a.m. -
1 stop6h 01m
Deal found 10/11C$ 855
Fri 4/128:00 a.m. -
1 stop17h 12m
Sun 6/122:27 p.m. -
2 stops25h 18m
Deal found 10/11C$ 906
Sat 21/116:15 a.m. -
1 stop5h 22m
Sat 28/117:30 a.m. -
1 stop5h 39m
Deal found 10/11C$ 936

Find flight deals from Ontario to St. Louis

Round-trip from

C$ 556

One-way from

C$ 337

Popular in

March

Cheapest in

January

Average price

C$ 923

Good round-trip deal

C$ 823 or less
9/12-16/12
  • 9/12-16/12
  • 3 total stops
  • 67h 57m total
  • Ontario to St. Louis
Search Deals
1/3-31/12
  • 1/3-31/12
  • 1 total stop
  • 10h 24m total
  • Ontario to St. Louis
Search Deals
Highest demand for flights based on searches. 11% potential increase in price (C$ 144 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease (C$ 67 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2026
Search Deals
Price to beat on a round-trip flight from Ontario to Lambert-St Louis.
Search Deals

Cheapflights Fare Finder

 
Use the filters below to find and compare flights from Ontario to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

TorontoSt. Louis

YYZ Toronto Pearson Intl - STL Lambert-St Louis

YYZSTL

Toronto Pearson Intl

Wed 2/12

3:22 p.m.-12:02 a.m.

1 stop9h 40m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 346

TorontoSt. Louis

YYZ Toronto Pearson Intl - STL Lambert-St Louis

YYZSTL

Toronto Pearson Intl

Mon 23/11

6:30 a.m.-4:20 p.m.

2 stops34h 50m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 366

TorontoSt. Louis

YYZ Toronto Pearson Intl - STL Lambert-St Louis

YYZSTL

Toronto Pearson Intl

Tue 8/12

12:20 p.m.-12:12 a.m.

3 stops36h 52m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 373

TorontoSt. Louis

YYZ Toronto Pearson Intl - STL Lambert-St Louis

YYZSTL

Toronto Pearson Intl

Mon 1/3

6:30 a.m.-4:58 p.m.

2 stops35h 28m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 390

TorontoSt. Louis

YYZ Toronto Pearson Intl - STL Lambert-St Louis

YYZSTL

Toronto Pearson Intl

Fri 4/12

7:09 a.m.-4:47 p.m.

1 stop10h 38m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 404

TorontoSt. Louis

YYZ Toronto Pearson Intl - STL Lambert-St Louis

YYZSTL

Toronto Pearson Intl

Fri 4/12

9:55 a.m.-10:57 a.m.

2 stops26h 02m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 427
Quickest round-trip

TorontoSt. Louis

YYZ Toronto Pearson Intl - STL Lambert-St Louis

YYZSTL

Toronto Pearson Intl

Mon 23/11

1:16 p.m.-7:50 p.m.

1 stop7h 34m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 441

TorontoSt. Louis

YYZ Toronto Pearson Intl - STL Lambert-St Louis

YYZSTL

Toronto Pearson Intl

Thu 26/11

6:30 a.m.-12:25 p.m.

1 stop30h 55m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 449

TorontoSt. Louis

YYZ Toronto Pearson Intl - STL Lambert-St Louis

YYZSTL

Toronto Pearson Intl

Wed 2/12

7:20 a.m.-7:26 p.m.

2 stops13h 06m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 462

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Thu 24/12

3:10 p.m.-11:38 p.m.

2 stops9h 28m

Lambert-St Louis

Wed 31/12

12:00 a.m.-1:00 a.m.

Nonstop0h 00m

C$ 468

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/11

Showing 1-10 of 30 resultsSorted by cheapest first
1
2
3

Best time to book a flight from Ontario to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Ontario with our price prediction graph.
Estimated round-trip price

Cheapflights Insights

Everything you need to know about your flight from Ontario to St. Louis

What is the cheapest month to book a flight from Region of Ontario to St. Louis?

Currently, January is the cheapest month in which you can book a flight from Region of Ontario to St. Louis (average of C$ 595). Flying from Region of Ontario to St. Louis in November is currently the most expensive (average of C$ 927). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from ON to STL?

It’s optimal to fly from Region of Ontario to St. Louis in the afternoon. By choosing this option you can save up to 36% on the cost of your flight, compared to a flight in the evening.

How much does it cost to fly round-trip from Region of Ontario to St. Louis?

Airfare is below average for this route at the moment.
Region of Ontario to St. Louis flights typically cost between C$ 824 and C$ 1,206 in December.
The cheapest round-trip price found within the last 5 days was C$ 556 on Multiple Airlines (9 Dec-16 Dec).

How far ahead should I book a flight from Region of Ontario to St. Louis?

To ensure you get the cheapest price possible for a flight from Region of Ontario to St. Louis, you should look to book at least 65 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

Related info for your journey

  • What airport do you fly into for flights to St. Louis from Ontario?

    Most people fly into Lambert-St Louis (STL) if they book a flight to St. Louis from Ontario. Lambert-St Louis is conveniently located just 20.4 km from St. Louis’s city centre.

  • How long is the flight from Region of Ontario to St. Louis?

    Delta and United Airlines can get you from Region of Ontario to St. Louis in just under 7h 29m. Your travel time can differ by up to 1h 40m. The distance between Region of Ontario and St. Louis is about 1051 km. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • What are the most popular routes from Region of Ontario to St. Louis?

    While some choose either Montreal Pierre Elliott Trudeau Intl - Lambert-St Louis or Ottawa - Lambert-St Louis, Toronto Pearson Intl - Lambert-St Louis is the most popular route from Region of Ontario to St. Louis.

  • What are the most reliable airlines from Region of Ontario to St. Louis?

    Consider Air Canada (72%), Jazz (72%) or United Airlines (72%) when booking your flight. These represent the most reliable airlines when flying from Region of Ontario to St. Louis.

  • What are the cheapest flights from Region of Ontario to St. Louis?

    Looking for the cheapest flight from Region of Ontario to St. Louis? While on average our users pay C$ 891, our data indicates the cheapest price to be C$ 790. The most popular route (Toronto Pearson Intl - Lambert-St Louis), is priced around C$ 556.

  • Can I find deals for flights from Ontario to St. Louis that include hotel bookings?

    Yes. In addition to deals on Ontario to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Ontario to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to St. Louis.

  • Can I find deals for business class flights from Ontario to St. Louis?

    Yes. Cheapflights offers flight deals from Ontario to St. Louis by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Region of Ontario to St. Louis?

    Currently, January is the cheapest month in which you can book a flight from Region of Ontario to St. Louis (average of C$ 595). Flying from Region of Ontario to St. Louis in November is currently the most expensive (average of C$ 927). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Travelling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Chesterfield

Browse thousands of different options on Cheapflights for your next trip

Top 2 airlines flying from Ontario to St. Louis

AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapestC$ 363AverageC$ 648FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Air CanadaCheapestC$ 418AverageC$ 797FlexibilityNo cancel feeOn-time67%
Search Air Canada flights

Fly with Cheapflights

How does Cheapflights help users find flights from Ontario to St. Louis?

When you search for this flight from Ontario to St. Louis, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

Why should you use Cheapflights to find cheap flight tickets from Ontario to St. Louis?

Cheapflights helps you find that perfect flight to St. Louis from Ontario by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Ontario to St. Louis with no change fees?

Certainly. Search results for flights to St. Louis from Ontario shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

Can Cheapflights notify me if prices for flights from Ontario to St. Louis become cheaper?

Yes! Start tracking prices for Ontario to St. Louis flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.