Which airlines fly to St. Louis?

Air Canada, United Airlines and American Airlines are the top three most popular airlines that fly to St. Louis from Region of Ontario according to our data. Air Canada is the first choice among our users, with 71% of people opting to fly with this airline when travelling to St. Louis. Keep in mind that there are 5 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.

How long does it take to fly to St. Louis?

Flight times vary depending on what airport in Region of Ontario you fly out of and what airport in St. Louis you fly into. For example, flying from Toronto to St. Louis takes 2h 29m on average. On the other hand, flying from Ottawa to St. Louis takes 6h on average. Keep in mind that it’s always quicker to opt for a non-stop flight, so be sure to check momondo to see if there are any available for your route.

What is the cheapest airline that flies from Ontario to Lambert-St Louis?

United Airlines, American Airlines, and Air Canada are the most popular carriers operating from Ontario to Lambert-St Louis

How many flights depart from Region of Ontario to St. Louis on average per day?

1 flights are operational daily from Region of Ontario to St. Louis as of November 2025. The most popular departure time for this route is 2:00p.m., with 100% of flights per day taking off in the afternoon.

How many flights depart from Region of Ontario to St. Louis on average per week?

The number of flights available between Region of Ontario and St. Louis is 12 per week as of November 2025. The most frequent departure day is Tue, with 17% of weekly flights leaving on this day.

When did momondo last update prices for flights from Ontario to Lambert-St Louis Airport?

Prices for flights from Ontario to Lambert-St Louis Airport are refreshed on a daily basis.

How many operators does momondo search for flights from Ontario to Lambert-St Louis Airport?

The number of operators available for flights from Ontario to Lambert-St Louis Airport is 5 as of November 2025.

How old do you have to be to fly from Ontario to Lambert-St Louis Airport?

The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ontario to Lambert-St Louis Airport.

What documentation or ID do you need to fly to Lambert-St Louis Airport?

The travel and health documents you'll need for your trip to Lambert-St Louis Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Lambert-St Louis Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

C$ 212 Cheap Flights from Ontario to St. Louis in 2025/26

1 adult

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Find the cheapest flights from Ontario to St. Louis

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

9:30 a.m. - 10:37 p.m.YOW-STL

14h 07m1 stop

5:11 p.m. - 5:13 p.m.STL-YOW

23h 02m1 stop

C$ 363Multiple Airlines

Find Deal

Fri, 16 Jan - Sun, 25 Jan

1:10 p.m. - 11:38 p.m.YYZ-STL

11h 28m1 stop

5:15 a.m. - 4:03 p.m.STL-YYZ

9h 48m1 stop

C$ 381American Airlines

Find Deal

Thu, 4 Dec - Mon, 15 Dec

8:20 p.m. - 8:59 a.m.YYZ-STL

13h 39m1 stop

3:30 p.m. - 11:43 a.m.STL-YYZ

19h 13m1 stop

C$ 401Multiple Airlines

Find Deal

Sat, 6 Dec - Sun, 14 Dec

5:55 p.m. - 11:59 p.m.YOW-STL

7h 04m1 stop

9:57 a.m. - 9:56 p.m.STL-YOW

10h 59m2 stops

C$ 423United Airlines

Find Deal

Fri, 16 Jan - Sun, 25 Jan

2:48 p.m. - 7:48 p.m.YOW-STL

6h 00m1 stop

9:30 a.m. - 9:14 p.m.STL-YOW

10h 44m2 stops

C$ 504United Airlines

Find Deal

Tue, 7 Apr - Wed, 8 Apr

6:52 a.m. - 2:18 p.m.YOW-STL

8h 26m1 stop

4:05 p.m. - 11:04 p.m.STL-YOW

5h 59m1 stop

C$ 505Air Canada

Find Deal

Tue, 7 Apr - Wed, 8 Apr

6:00 a.m. - 12:29 p.m.YOW-STL

7h 29m2 stops

6:30 a.m. - 2:30 p.m.STL-YOW

7h 00m2 stops

C$ 506United Airlines

Find Deal

Fri, 16 Jan - Sun, 25 Jan

2:00 p.m. - 3:29 p.m.YYZ-STL

2h 29mdirect

4:05 p.m. - 7:06 p.m.STL-YYZ

2h 01mdirect

C$ 521Air Canada

Find Deal

Sat, 22 Nov - Mon, 24 Nov

6:30 a.m. - 12:04 p.m.YYZ-STL

6h 34m1 stop

6:40 a.m. - 11:24 a.m.STL-YYZ

3h 44m1 stop

C$ 549Delta

Find Deal

Sat, 22 Nov - Sat, 29 Nov

12:08 p.m. - 5:09 p.m.YYZ-STL

6h 01m1 stop

6:40 a.m. - 11:24 a.m.STL-YYZ

3h 44m1 stop

C$ 550Delta

Find Deal

Tue, 25 Nov - Fri, 28 Nov

American Airlines flights from Region of Ontario to St. Louis

Our best American Airlines deals on Region of Ontario to St. Louis flight tickets

American Airlines

4 Dec

YYZ1:10 p.m.Toronto Pearson Intl

11h 28m

1 stop

STL11:38 p.m.Lambert-St Louis

15 Dec

STL5:15 a.m.Lambert-St Louis

9h 48m

1 stop

YYZ4:03 p.m.Toronto Pearson Intl

C$ 381

Find similar

American Airlines

3 Mar

YYZ1:12 p.m.Toronto Pearson Intl

9h 59m

1 stop

STL10:11 p.m.Lambert-St Louis

4 Mar

STL6:00 a.m.Lambert-St Louis

9h 00m

1 stop

YYZ4:00 p.m.Toronto Pearson Intl

C$ 525

Find similar

American Airlines

3 Mar

YYZ11:38 a.m.Toronto Pearson Intl

7h 33m

1 stop

STL6:11 p.m.Lambert-St Louis

4 Mar

STL6:00 a.m.Lambert-St Louis

9h 00m

1 stop

YYZ4:00 p.m.Toronto Pearson Intl

C$ 545

Find similar

WestJet flights from Region of Ontario to St. Louis

Our best WestJet deals on Region of Ontario to St. Louis flight tickets

WestJet

23 Dec

YYZ12:09 p.m.Toronto Pearson Intl

5h 52m

1 stop

STL5:01 p.m.Lambert-St Louis

30 Dec

STL6:05 a.m.Lambert-St Louis

16h 34m

2 stops

YYZ11:39 p.m.Toronto Pearson Intl

C$ 732

Find similar

WestJet

17 Feb

YUL6:45 a.m.Montreal Pierre Elliott Trudeau Intl

15h 00m

2 stops

STL8:45 p.m.Lambert-St Louis

25 Feb

STL6:10 a.m.Lambert-St Louis

23h 55m

2 stops

YUL7:05 a.m.Montreal Pierre Elliott Trudeau Intl

C$ 949

Find similar

WestJet

17 Nov

YUL12:50 p.m.Montreal Pierre Elliott Trudeau Intl

5h 19m

1 stop

STL5:09 p.m.Lambert-St Louis

23 Nov

STL6:09 p.m.Lambert-St Louis

4h 17m

1 stop

YUL11:26 p.m.Montreal Pierre Elliott Trudeau Intl

C$ 1,136

Find similar

Fly from

Fly to

Route

Depart

Return

Price

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 16/1

9:30 a.m.-10:37 p.m.

1 stop14h 07m

Lambert-St Louis

Sun 25/1

5:11 p.m.-5:13 p.m.

1 stop23h 02m

C$ 363

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Thu 4/12

1:10 p.m.-11:38 p.m.

1 stop11h 28m

Lambert-St Louis

Mon 15/12

5:15 a.m.-4:03 p.m.

1 stop9h 48m

C$ 381

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Sat 6/12

8:20 p.m.-8:59 a.m.

1 stop13h 39m

Lambert-St Louis

Sun 14/12

3:30 p.m.-11:43 a.m.

1 stop19h 13m

C$ 401

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 16/1

5:55 p.m.-11:59 p.m.

1 stop7h 04m

Lambert-St Louis

Sun 25/1

9:57 a.m.-9:56 p.m.

2 stops10h 59m

C$ 423

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 7/4

2:48 p.m.-7:48 p.m.

1 stop6h 00m

Lambert-St Louis

Wed 8/4

9:30 a.m.-9:14 p.m.

2 stops10h 44m

C$ 504

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 7/4

6:52 a.m.-2:18 p.m.

1 stop8h 26m

Lambert-St Louis

Wed 8/4

4:05 p.m.-11:04 p.m.

1 stop5h 59m

C$ 505

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 16/1

6:00 a.m.-12:29 p.m.

2 stops7h 29m

Lambert-St Louis

Sun 25/1

6:30 a.m.-2:30 p.m.

2 stops7h 00m

C$ 506

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Sat 22/11

2:00 p.m.-3:29 p.m.

Nonstop2h 29m

Lambert-St Louis

Mon 24/11

4:05 p.m.-7:06 p.m.

Nonstop2h 01m

C$ 521

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Sat 22/11

6:30 a.m.-12:04 p.m.

1 stop6h 34m

Lambert-St Louis

Sat 29/11

6:40 a.m.-11:24 a.m.

1 stop3h 44m

C$ 549

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Tue 25/11

12:08 p.m.-5:09 p.m.

1 stop6h 01m

Lambert-St Louis

Fri 28/11

6:40 a.m.-11:24 a.m.

1 stop3h 44m

C$ 550

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from Region of Ontario to St. Louis

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

Prices

Airlines

Other information

What is the cheapest month to fly to St. Louis?

The month of June is, on average, the cheapest month to fly to St. Louis from Region of Ontario, with most prices found around C$ 525. If you don’t want to visit St. Louis in June, then you should wait until August to fly from Region of Ontario, when ticket prices are also cheap, with an average price of C$ 560.

What is the cheapest day to depart on your flight to St. Louis?

Our data shows that Thursday is the least expensive day to fly to St. Louis. Tickets to fly out on this day can be as low as C$ 589. The most expensive day to fly to St. Louis is Monday, with ticket prices averaging around C$ 776.

What is the cheapest time of day to depart on your flight to St. Louis?

The cheapest time of day to fly to St. Louis is in the morning when flights can be purchased for as low as C$ 552. If you have a flexible travel schedule, then try to avoid flying at noon when prices are C$ 703 on average. Flights to St. Louis from Region of Ontario at noon are generally more expensive because this time of day is more convenient for travellers’ schedules.

What is the cheapest Ontario to Lambert-St Louis flight route?

Fly from Toronto Pearson Intl to Lambert-St Louis for the best Ontario - Lambert-St Louis flight prices

How far in advance should I book a flight to St. Louis?

You are more likely to see cheaper flights to St. Louis from Region of Ontario when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around C$ 691 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Region of Ontario for as low as C$ 508 on momondo.

What cabin class options are available on Ontario to Lambert-St Louis flights?

There is only 1 cabin class available to choose from on Ontario to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Region of Ontario to St. Louis flights?

No. A direct flight is the cheapest option for a flight between Region of Ontario to St. Louis.

Cheap Region of Ontario to St. Louis flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Region of Ontario to St. Louis

Best price found	C$ 597
Fastest flight time	2h 29m
Direct flights	Every day
Airports in St. Louis	1 airport

The best flight deal from Region of Ontario to St. Louis found on momondo in the last 72 hours is C$ 597

The fastest flight from Region of Ontario to St. Louis takes 2h 29m

Direct flights go from Region of Ontario to St. Louis every day.

There is 1 airport near St. Louis: Lambert-St Louis (STL)

Search flight deals

When did momondo last update prices for flights from Ontario to Lambert-St Louis Airport?
Prices for flights from Ontario to Lambert-St Louis Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Ontario to Lambert-St Louis Airport?
The number of operators available for flights from Ontario to Lambert-St Louis Airport is 5 as of November 2025.
How old do you have to be to fly from Ontario to Lambert-St Louis Airport?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ontario to Lambert-St Louis Airport.
What documentation or ID do you need to fly to Lambert-St Louis Airport?
The travel and health documents you'll need for your trip to Lambert-St Louis Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Lambert-St Louis Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from Region of Ontario to St. Louis?
momondo data reveals that the most frequently booked plane model on the route from Region of Ontario to St. Louis is Canadair (Bombardier) Regional Jet 900, representing 58.90% of all bookings. The subsequent popular models are Embraer 175 at 27.40%, Airbus A319 at 4.11%, and Airbus A320-100/200 at 4.11%.

Best airlines flying from Region of Ontario to St. Louis

Compare and see reviews for airlines that fly from Region of Ontario to St. Louis with momondo

Airline	Rating	Free Cancellation	Price
American Airlines	PriceFrom C$ 439	Free Cancellation	Rating 7.2 11,040 reviews	Search American Airlines flights
United Airlines	PriceFrom C$ 444	Free Cancellation	Rating 7.4 9,007 reviews	Search United Airlines flights
Air Canada	PriceFrom C$ 480	Free Cancellation	Rating 7.1 10,416 reviews	Search Air Canada flights
Delta	PriceFrom C$ 485	Free Cancellation	Rating 7.9 8,001 reviews	Search Delta flights
WestJet	PriceFrom C$ 569	Free Cancellation	Rating 7.2 3,155 reviews	Search WestJet flights

Chesterfield

Litchfield

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to St. Louis?

It is quick and easy to find Ontario to St. Louis flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to St. Louis that suits you.

Can I find flights from Ontario to St. Louis with flexible booking policies on momondo?

Flights from Ontario to St. Louis with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from Ontario to St. Louis?

Once you have performed a search for Ontario to St. Louis flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from Ontario to St. Louis right now. Can momondo alert me if prices change?

Yes momondo offers price alerts on flights to St. Louis from Ontario. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

An easier way to manage your St. Louis trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

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Cheap flights from Ontario to St. Louis from C$ 212

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to St. Louis departing on 29/1. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

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Find the cheapest flights from Ontario to St. Louis

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American Airlines flights from Region of Ontario to St. Louis

Our best American Airlines deals on Region of Ontario to St. Louis flight tickets

WestJet flights from Region of Ontario to St. Louis

Our best WestJet deals on Region of Ontario to St. Louis flight tickets

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

See travel insights to St. Louis from

How to get the cheapest flight ticket from Region of Ontario to St. Louis

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to St. Louis?

What is the cheapest day to depart on your flight to St. Louis?

Our data shows that Thursday is the least expensive day to fly to St. Louis. Tickets to fly out on this day can be as low as C$ 589. The most expensive day to fly to St. Louis is Monday, with ticket prices averaging around C$ 776.

What is the cheapest time of day to depart on your flight to St. Louis?

What is the cheapest Ontario to Lambert-St Louis flight route?

Fly from Toronto Pearson Intl to Lambert-St Louis for the best Ontario - Lambert-St Louis flight prices

How far in advance should I book a flight to St. Louis?

What cabin class options are available on Ontario to Lambert-St Louis flights?

There is only 1 cabin class available to choose from on Ontario to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Region of Ontario to St. Louis flights?

No. A direct flight is the cheapest option for a flight between Region of Ontario to St. Louis.

What is the cheapest airline that flies from Ontario to Lambert-St Louis?

United Airlines, American Airlines, and Air Canada are the most popular carriers operating from Ontario to Lambert-St Louis

Which airlines fly to St. Louis?

How many flights depart from Region of Ontario to St. Louis on average per day?

1 flights are operational daily from Region of Ontario to St. Louis as of November 2025. The most popular departure time for this route is 2:00p.m., with 100% of flights per day taking off in the afternoon.

How many flights depart from Region of Ontario to St. Louis on average per week?

The number of flights available between Region of Ontario and St. Louis is 12 per week as of November 2025. The most frequent departure day is Tue, with 17% of weekly flights leaving on this day.

How long does it take to fly to St. Louis?

Cheap Region of Ontario to St. Louis flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Region of Ontario to St. Louis

Best price found

Fastest flight time

Direct flights

Airports in St. Louis

When did momondo last update prices for flights from Ontario to Lambert-St Louis Airport?

How many operators does momondo search for flights from Ontario to Lambert-St Louis Airport?

How old do you have to be to fly from Ontario to Lambert-St Louis Airport?

What documentation or ID do you need to fly to Lambert-St Louis Airport?

What is the most popular plane model from Region of Ontario to St. Louis?

Best airlines flying from Region of Ontario to St. Louis

Compare and see reviews for airlines that fly from Region of Ontario to St. Louis with momondo

Travelling to a place near St. Louis?

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to St. Louis?

Can I find flights from Ontario to St. Louis with flexible booking policies on momondo?

How can momondo help me find flights from Ontario to St. Louis?

I’m not ready to book a flight from Ontario to St. Louis right now. Can momondo alert me if prices change?

An easier way to manage your St. Louis trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to the United States

Airports servicing Missouri