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 03m on average. On the other hand, flying from Ottawa to St. Louis takes 6h 49m 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.

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 42 per week as of August 2025. The most frequent departure day is Mon, with 14% of weekly flights leaving on this day.

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

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

Which airlines fly to St. Louis?

Air Canada, United Airlines and WestJet 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 76% of people opting to fly with this airline when travelling to St. Louis. Keep in mind that there are 4 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.

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

6 flights are operational daily from Region of Ontario to St. Louis as of August 2025. The most popular departure time for this route is 2:00p.m., with 50% of flights per day taking off in the afternoon.

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 4 as of August 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$ 260 Cheap Flights from Ontario to St. Louis in 2025

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

4:44 p.m. - 11:56 p.m.YYZ-STL

8h 12m1 stop

6:00 a.m. - 4:04 p.m.STL-YYZ

9h 04m1 stop

C$ 443American Airlines

Find Deal

Sat, 8 Nov - Sat, 15 Nov

12:31 p.m. - 8:32 p.m.YUL-STL

9h 01m1 stop

5:25 p.m. - 11:46 a.m.STL-YUL

17h 21m1 stop

C$ 446American Airlines

Find Deal

Sat, 20 Sep - Sat, 27 Sep

6:00 a.m. - 2:43 p.m.YUL-STL

9h 43m1 stop

7:00 a.m. - 8:04 p.m.STL-YUL

12h 04m2 stops

C$ 530Delta

Find Deal

Wed, 3 Sep - Sat, 6 Sep

7:00 a.m. - 3:44 p.m.YYZ-STL

9h 44m1 stop

6:30 a.m. - 9:40 p.m.STL-YYZ

14h 10m2 stops

C$ 552United Airlines

Find Deal

Sat, 20 Sep - Sat, 27 Sep

6:00 a.m. - 4:06 p.m.YUL-STL

11h 06m2 stops

7:00 a.m. - 8:04 p.m.STL-YUL

12h 04m2 stops

C$ 567Delta

Find Deal

Wed, 3 Sep - Sat, 6 Sep

4:00 p.m. - 6:36 p.m.YYZ-STL

27h 36m2 stops

1:57 p.m. - 10:40 p.m.STL-YYZ

7h 43m1 stop

C$ 572

Find Deal

Thu, 11 Sep - Mon, 15 Sep

4:00 p.m. - 5:55 p.m.YYZ-STL

26h 55m2 stops

10:54 a.m. - 2:25 p.m.STL-YYZ

26h 31m2 stops

C$ 589

Find Deal

Fri, 17 Oct - Sun, 19 Oct

1:00 p.m. - 8:00 p.m.YYZ-STL

8h 00m1 stop

9:15 a.m. - 12:15 p.m.STL-YYZ

2h 00mdirect

C$ 600Air Canada

Find Deal

Thu, 28 Aug - Sun, 31 Aug

2:15 p.m. - 3:18 p.m.YYZ-STL

2h 03mdirect

9:15 a.m. - 12:11 p.m.STL-YYZ

1h 56mdirect

C$ 607Air Canada

Find Deal

Thu, 11 Sep - Mon, 15 Sep

6:20 p.m. - 10:49 a.m.YUL-STL

17h 29m2 stops

5:00 a.m. - 5:26 p.m.STL-YUL

11h 26m1 stop

C$ 611United Airlines

Find Deal

Mon, 20 Oct - Wed, 22 Oct

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

8 Nov

YYZ4:44 p.m.Toronto Pearson Intl

8h 12m

1 stop

STL11:56 p.m.Lambert-St Louis

15 Nov

STL6:00 a.m.Lambert-St Louis

9h 04m

1 stop

YYZ4:04 p.m.Toronto Pearson Intl

C$ 443

Find similar

American Airlines

20 Sep

YUL12:31 p.m.Montreal Pierre Elliott Trudeau Intl

9h 01m

1 stop

STL8:32 p.m.Lambert-St Louis

27 Sep

STL5:25 p.m.Lambert-St Louis

17h 21m

1 stop

YUL11:46 a.m.Montreal Pierre Elliott Trudeau Intl

C$ 446

Find similar

American Airlines

20 Sep

YUL10:34 a.m.Montreal Pierre Elliott Trudeau Intl

12h 19m

2 stops

STL9:53 p.m.Lambert-St Louis

27 Sep

STL7:23 a.m.Lambert-St Louis

8h 10m

1 stop

YUL4:33 p.m.Montreal Pierre Elliott Trudeau Intl

C$ 459

Find similar

United Airlines flights from Region of Ontario to St. Louis

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

United Airlines

20 Sep

YYZ7:00 a.m.Toronto Pearson Intl

9h 44m

1 stop

STL3:44 p.m.Lambert-St Louis

27 Sep

STL6:30 a.m.Lambert-St Louis

14h 10m

2 stops

YYZ9:40 p.m.Toronto Pearson Intl

C$ 552

Find similar

United Airlines

20 Oct

YUL6:20 p.m.Montreal Pierre Elliott Trudeau Intl

17h 29m

2 stops

STL10:49 a.m.Lambert-St Louis

22 Oct

STL5:00 a.m.Lambert-St Louis

11h 26m

1 stop

YUL5:26 p.m.Montreal Pierre Elliott Trudeau Intl

C$ 611

Find similar

United Airlines

11 Sep

YYZ7:00 a.m.Toronto Pearson Intl

14h 46m

3 stops

STL8:46 p.m.Lambert-St Louis

15 Sep

STL5:30 p.m.Lambert-St Louis

5h 28m

1 stop

YYZ11:58 p.m.Toronto Pearson Intl

C$ 630

Find similar

Fly from

Fly to

Route

Depart

Return

Price

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Sat 8/11

4:44 p.m.-11:56 p.m.

1 stop8h 12m

Lambert-St Louis

Sat 15/11

6:00 a.m.-4:04 p.m.

1 stop9h 04m

C$ 443

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sat 20/9

12:31 p.m.-8:32 p.m.

1 stop9h 01m

Lambert-St Louis

Sat 27/9

5:25 p.m.-11:46 a.m.

1 stop17h 21m

C$ 446

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 3/9

6:00 a.m.-2:43 p.m.

1 stop9h 43m

Lambert-St Louis

Sat 6/9

7:00 a.m.-8:04 p.m.

2 stops12h 04m

C$ 530

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Sat 20/9

7:00 a.m.-3:44 p.m.

1 stop9h 44m

Lambert-St Louis

Sat 27/9

6:30 a.m.-9:40 p.m.

2 stops14h 10m

C$ 552

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 3/9

6:00 a.m.-4:06 p.m.

2 stops11h 06m

Lambert-St Louis

Sat 6/9

7:00 a.m.-8:04 p.m.

2 stops12h 04m

C$ 567

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Thu 11/9

4:00 p.m.-6:36 p.m.

2 stops27h 36m

Lambert-St Louis

Mon 15/9

1:57 p.m.-10:40 p.m.

1 stop7h 43m

C$ 572

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Fri 17/10

4:00 p.m.-5:55 p.m.

2 stops26h 55m

Lambert-St Louis

Sun 19/10

10:54 a.m.-2:25 p.m.

2 stops26h 31m

C$ 589

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Thu 28/8

1:00 p.m.-8:00 p.m.

1 stop8h 00m

Lambert-St Louis

Sun 31/8

9:15 a.m.-12:15 p.m.

Nonstop2h 00m

C$ 600

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Thu 11/9

2:15 p.m.-3:18 p.m.

Nonstop2h 03m

Lambert-St Louis

Mon 15/9

9:15 a.m.-12:11 p.m.

Nonstop1h 56m

C$ 607

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 20/10

6:20 p.m.-10:49 a.m.

2 stops17h 29m

Lambert-St Louis

Wed 22/10

5:00 a.m.-5:26 p.m.

1 stop11h 26m

C$ 611

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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$ 512. If you don’t want to visit St. Louis in June, then you should wait until November to fly from Region of Ontario, when ticket prices are also cheap, with an average price of C$ 638.

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$ 596. The most expensive day to fly to St. Louis is Sunday, with ticket prices averaging around C$ 768.

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$ 539. If you have a flexible travel schedule, then try to avoid flying at noon when prices are C$ 689 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$ 670 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$ 495 on momondo.

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

There are 1 cabin classes 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?

You could potentially save up to 9% on your flight if you consider stops on a Region of Ontario to St. Louis flight.

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$ 260
Fastest flight time	2h 03m
Direct flights	Every day
Airports in St. Louis	1 airport

The best one-way flight to St. Louis from Region of Ontario in the past 72 hours is C$ 260. The best round-trip flight deal from Region of Ontario to St. Louis found on momondo in the last 72 hours is C$ 443.

The fastest flight from Region of Ontario to St. Louis takes 2h 03m

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 4 as of August 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 60.19% of all bookings. The subsequent popular models are Airbus A220-300 at 28.91%, Airbus A319 at 2.84%, and Airbus A320-100/200 at 2.84%.

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
Air Canada	PriceFrom C$ 470	Free Cancellation	Rating 7.1 9,893 reviews	Search Air Canada flights
Delta	PriceFrom C$ 472	Free Cancellation	Rating 8.0 7,985 reviews	Search Delta flights
United Airlines	PriceFrom C$ 477	Free Cancellation	Rating 7.4 8,917 reviews	Search United Airlines flights
WestJet	PriceFrom C$ 555	Free Cancellation	Rating 7.2 3,002 reviews	Search WestJet flights

Edwardsville

Chesterfield

Collinsville

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

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Cheap flights from Ontario to St. Louis from C$ 260

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 1/10. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Big names, great deals

Big names, great deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

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Find the cheapest flights from Ontario to St. Louis

Cheap round-trip flights

Cheap one-way flights

Cheap last-minute flights

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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

United Airlines flights from Region of Ontario to St. Louis

Our best United Airlines 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$ 596. The most expensive day to fly to St. Louis is Sunday, with ticket prices averaging around C$ 768.

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 are 1 cabin classes 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?

You could potentially save up to 9% on your flight if you consider stops on a Region of Ontario to St. Louis flight.

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

American Airlines, Delta, 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?

6 flights are operational daily from Region of Ontario to St. Louis as of August 2025. The most popular departure time for this route is 2:00p.m., with 50% 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 42 per week as of August 2025. The most frequent departure day is Mon, with 14% 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