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 06m on average. On the other hand, flying from Ottawa to St. Louis takes 5h 12m 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 and Delta are the most popular carriers operating from Ontario to Lambert-St Louis

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 73% 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 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 14 per week as of February 2026. The most frequent departure day is Mon, with 14% of weekly flights leaving on this day.

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

2 flights are operational daily from Region of Ontario to St. Louis as of February 2026. The most popular departure time for this route is 2:00p.m., with 100% 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 5 as of February 2026.

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$ 189 Cheap Flights from Ontario to St. Louis in 2026

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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.

7:10 a.m. - 10:27 p.m.

YYZ

STL

16h 17m

1 stop

11:32 a.m. - 11:26 a.m.

STL

YYZ

22h 54m

2 stops

C$ 365Multiple Airlines

Wed, 4 Mar - Wed, 11 Mar

7:10 a.m. - 10:27 p.m.

YYZ

STL

16h 17m

1 stop

11:32 a.m. - 11:20 p.m.

STL

YYZ

10h 48m

2 stops

C$ 373Multiple Airlines

Wed, 4 Mar - Wed, 11 Mar

7:10 a.m. - 10:27 p.m.

YYZ

STL

16h 17m

1 stop

12:14 p.m. - 7:55 p.m.

STL

YYZ

30h 41m

1 stop

C$ 388Multiple Airlines

Wed, 4 Mar - Wed, 11 Mar

10:44 a.m. - 9:08 p.m.

YOW

STL

11h 24m

1 stop

7:45 a.m. - 5:07 p.m.

STL

YOW

8h 22m

1 stop

C$ 432United Airlines

Thu, 9 Apr - Sat, 11 Apr

5:11 p.m. - 9:58 p.m.

YOW

STL

5h 47m

1 stop

10:00 a.m. - 5:07 p.m.

STL

YOW

6h 07m

1 stop

C$ 436United Airlines

Fri, 27 Mar - Mon, 30 Mar

12:30 p.m. - 11:46 p.m.

YUL

STL

12h 16m

1 stop

5:21 p.m. - 11:44 a.m.

STL

YUL

17h 23m

1 stop

C$ 477American Airlines

Mon, 20 Apr - Sat, 25 Apr

7:15 a.m. - 3:29 p.m.

YOW

STL

9h 14m

1 stop

4:05 p.m. - 11:18 p.m.

STL

YOW

6h 13m

1 stop

C$ 502Air Canada

Sun, 1 Mar - Wed, 4 Mar

7:15 a.m. - 3:29 p.m.

YOW

STL

9h 14m

1 stop

4:05 p.m. - 1:38 a.m.

STL

YOW

8h 33m

1 stop

C$ 554Air Canada

Sun, 1 Mar - Wed, 4 Mar

6:45 p.m. - 11:59 p.m.

YUL

STL

6h 14m

1 stop

6:04 p.m. - 11:13 p.m.

STL

YUL

4h 09m

1 stop

C$ 645Delta

Sun, 10 May - Sat, 16 May

6:00 a.m. - 1:05 p.m.

YUL

STL

8h 05m

1 stop

5:47 p.m. - 11:41 p.m.

STL

YUL

4h 54m

1 stop

C$ 647Delta

Sun, 10 May - Sat, 16 May

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

20 Apr

YUL12:30 p.m.Montreal Pierre Elliott Trudeau Intl

12h 16m

1 stop

STL11:46 p.m.Lambert-St Louis

25 Apr

STL5:21 p.m.Lambert-St Louis

17h 23m

1 stop

YUL11:44 a.m.Montreal Pierre Elliott Trudeau Intl

C$ 477

American Airlines

3 Apr

YUL2:25 p.m.Montreal Pierre Elliott Trudeau Intl

19h 10m

1 stop

STL8:35 a.m.Lambert-St Louis

11 Apr

STL8:03 p.m.Lambert-St Louis

14h 41m

1 stop

YUL11:44 a.m.Montreal Pierre Elliott Trudeau Intl

C$ 526

American Airlines

20 May

YYZ1:15 p.m.Toronto Pearson Intl

11h 41m

1 stop

STL11:56 p.m.Lambert-St Louis

24 May

STL6:00 a.m.Lambert-St Louis

4h 04m

1 stop

YYZ11:04 a.m.Toronto Pearson Intl

C$ 573

Air Canada flights from Region of Ontario to St. Louis

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

Air Canada

1 Mar

YOW7:15 a.m.Ottawa

9h 14m

1 stop

STL3:29 p.m.Lambert-St Louis

4 Mar

STL4:05 p.m.Lambert-St Louis

6h 13m

1 stop

YOW11:18 p.m.Ottawa

C$ 502

Air Canada

1 Mar

YOW7:15 a.m.Ottawa

9h 14m

1 stop

STL3:29 p.m.Lambert-St Louis

4 Mar

STL4:05 p.m.Lambert-St Louis

8h 33m

1 stop

YOW1:38 a.m.Ottawa

C$ 554

Air Canada

1 Mar

YOW7:15 a.m.Ottawa

9h 14m

1 stop

STL3:29 p.m.Lambert-St Louis

4 Mar

STL7:41 a.m.Lambert-St Louis

9h 00m

2 stops

YOW5:41 p.m.Ottawa

C$ 569

Fly from

Fly to

Route

Depart

Return

Price

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Wed 4/3

7:10 a.m.-10:27 p.m.

1 stop16h 17m

Lambert-St Louis

Wed 11/3

11:32 a.m.-11:26 a.m.

2 stops22h 54m

C$ 365

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Wed 4/3

7:10 a.m.-10:27 p.m.

1 stop16h 17m

Lambert-St Louis

Wed 11/3

11:32 a.m.-11:20 p.m.

2 stops10h 48m

C$ 373

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Wed 4/3

7:10 a.m.-10:27 p.m.

1 stop16h 17m

Lambert-St Louis

Wed 11/3

12:14 p.m.-7:55 p.m.

1 stop30h 41m

C$ 388

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 9/4

10:44 a.m.-9:08 p.m.

1 stop11h 24m

Lambert-St Louis

Sat 11/4

7:45 a.m.-5:07 p.m.

1 stop8h 22m

C$ 432

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 27/3

5:11 p.m.-9:58 p.m.

1 stop5h 47m

Lambert-St Louis

Mon 30/3

10:00 a.m.-5:07 p.m.

1 stop6h 07m

C$ 436

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 20/4

12:30 p.m.-11:46 p.m.

1 stop12h 16m

Lambert-St Louis

Sat 25/4

5:21 p.m.-11:44 a.m.

1 stop17h 23m

C$ 477

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/3

7:15 a.m.-3:29 p.m.

1 stop9h 14m

Lambert-St Louis

Wed 4/3

4:05 p.m.-11:18 p.m.

1 stop6h 13m

C$ 502

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/3

7:15 a.m.-3:29 p.m.

1 stop9h 14m

Lambert-St Louis

Wed 4/3

4:05 p.m.-1:38 a.m.

1 stop8h 33m

C$ 554

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sun 10/5

6:45 p.m.-11:59 p.m.

1 stop6h 14m

Lambert-St Louis

Sat 16/5

6:04 p.m.-11:13 p.m.

1 stop4h 09m

C$ 645

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sun 10/5

6:00 a.m.-1:05 p.m.

1 stop8h 05m

Lambert-St Louis

Sat 16/5

5:47 p.m.-11:41 p.m.

1 stop4h 54m

C$ 647

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$ 509. If you don’t want to visit St. Louis in June, then you should wait until January to fly from Region of Ontario, when ticket prices are also cheap, with an average price of C$ 540.

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$ 553. The most expensive day to fly to St. Louis is Monday, with ticket prices averaging around C$ 805.

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$ 537. If you have a flexible travel schedule, then try to avoid flying at noon when prices are C$ 614 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$ 622 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$ 492 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$ 578
Fastest flight time	2h 06m
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$ 578

The fastest flight from Region of Ontario to St. Louis takes 2h 06m

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

There is 1 airport in St. Louis. From Region of Ontario there are direct flights to 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 February 2026.
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 Embraer 175, representing 77.36% of all bookings. The subsequent popular models are Airbus A319 at 5.66%, Airbus A320-100/200 at 5.66%, and Airbus A220-300 at 3.77%.

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
United Airlines	PriceFrom C$ 329	Free Cancellation	Rating 7.4 9,245 reviews	Search United Airlines flights
American Airlines	PriceFrom C$ 369	Free Cancellation	Rating 7.2 11,248 reviews	Search American Airlines flights
Air Canada	PriceFrom C$ 455	Free Cancellation	Rating 7.1 10,697 reviews	Search Air Canada flights
Delta	PriceFrom C$ 470	Free Cancellation	Rating 7.9 8,162 reviews	Search Delta flights
WestJet	PriceFrom C$ 552	Free Cancellation	Rating 7.2 3,255 reviews	Search WestJet flights

Chesterfield

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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Mon 9/3

Mon 16/3

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Cheap flights from Ontario to St. Louis from C$ 189

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 4/3. 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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Big names, great deals

Filter for what you want

Filter for what you want

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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

Air Canada flights from Region of Ontario to St. Louis

Our best Air Canada 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

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$ 553. The most expensive day to fly to St. Louis is Monday, with ticket prices averaging around C$ 805.

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 and Delta 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?

2 flights are operational daily from Region of Ontario to St. Louis as of February 2026. 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 14 per week as of February 2026. 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

Fly your favourite airline to St. Louis

Airlines are sorted and displayed according to clicks in the past 7 days on momondo

Popular Cities in the United States

Popular flights according to clicks in the last 7 days on momondo

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According to popular flight searches on momondo this year

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