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Cheap flights from St. Louis to Ontario from C$ 179

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Ontario departing on 24/2. 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 St. Louis to Ontario

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
10:11 p.m. - 6:43 a.m.
STL
-
YYZ
31h 32m
1 stop
Multiple Airlines Logo
7:10 a.m. - 10:27 p.m.
YYZ
-
STL
16h 17m
1 stop
C$ 341Multiple Airlines
Thu, 26 Feb - Wed, 4 Mar
Multiple Airlines Logo
10:11 p.m. - 11:11 p.m.
STL
-
YYZ
24h 00m
2 stops
Multiple Airlines Logo
7:10 a.m. - 10:27 p.m.
YYZ
-
STL
16h 17m
1 stop
C$ 348Multiple Airlines
Thu, 26 Feb - Wed, 4 Mar
Multiple Airlines Logo
3:49 p.m. - 2:20 p.m.
STL
-
YYZ
21h 31m
1 stop
Multiple Airlines Logo
3:40 p.m. - 10:37 a.m.
YYZ
-
STL
19h 57m
2 stops
C$ 359Multiple Airlines
Tue, 3 Mar - Tue, 17 Mar
Multiple Airlines Logo
8:17 p.m. - 2:20 p.m.
STL
-
YYZ
17h 03m
2 stops
Multiple Airlines Logo
7:10 a.m. - 10:27 p.m.
YYZ
-
STL
16h 17m
1 stop
C$ 385Multiple Airlines
Wed, 25 Feb - Wed, 4 Mar
Multiple Airlines Logo
8:17 p.m. - 2:20 p.m.
STL
-
YYZ
17h 03m
2 stops
Multiple Airlines Logo
8:20 p.m. - 7:02 a.m.
YYZ
-
STL
11h 42m
1 stop
C$ 396Multiple Airlines
Wed, 25 Feb - Thu, 5 Mar
American Airlines Logo
6:00 a.m. - 3:04 p.m.
STL
-
YUL
8h 04m
1 stop
American Airlines Logo
3:45 p.m. - 10:13 a.m.
YUL
-
STL
19h 28m
1 stop
C$ 504American Airlines
Tue, 17 Feb - Fri, 20 Feb
American Airlines Logo
10:37 a.m. - 10:56 p.m.
STL
-
YUL
11h 19m
2 stops
American Airlines Logo
3:45 p.m. - 10:13 a.m.
YUL
-
STL
19h 28m
1 stop
C$ 518American Airlines
Tue, 17 Feb - Fri, 20 Feb
Air Canada Logo
4:05 p.m. - 9:21 p.m.
STL
-
YXU
4h 16m
1 stop
Air Canada Logo
9:25 a.m. - 3:29 p.m.
YXU
-
STL
7h 04m
1 stop
C$ 1,326Air Canada
Mon, 2 Mar - Wed, 4 Mar
United Airlines Logo
7:41 a.m. - 9:21 p.m.
STL
-
YXU
12h 40m
2 stops
United Airlines Logo
9:25 a.m. - 9:05 p.m.
YXU
-
STL
12h 40m
2 stops
C$ 1,327United Airlines
Mon, 2 Mar - Wed, 4 Mar
Air Canada Logo
7:41 a.m. - 9:21 p.m.
STL
-
YXU
12h 40m
2 stops
Air Canada Logo
9:25 a.m. - 3:29 p.m.
YXU
-
STL
7h 04m
1 stop
C$ 1,339Air Canada
Mon, 2 Mar - Wed, 4 Mar

American Airlines flights from St. Louis to Region of Ontario

Our best American Airlines deals on St. Louis to Region of Ontario flight tickets
American Airlines
17 Feb
STL6:00 a.m.Lambert-St Louis
8h 04m
1 stop
YUL3:04 p.m.Montreal Pierre Elliott Trudeau Intl
20 Feb
YUL3:45 p.m.Montreal Pierre Elliott Trudeau Intl
19h 28m
1 stop
STL10:13 a.m.Lambert-St Louis
C$ 504
American Airlines
17 Feb
STL10:37 a.m.Lambert-St Louis
11h 19m
2 stops
YUL10:56 p.m.Montreal Pierre Elliott Trudeau Intl
20 Feb
YUL3:45 p.m.Montreal Pierre Elliott Trudeau Intl
19h 28m
1 stop
STL10:13 a.m.Lambert-St Louis
C$ 518
American Airlines
5 Mar
STL6:00 a.m.Lambert-St Louis
8h 04m
1 stop
YUL3:04 p.m.Montreal Pierre Elliott Trudeau Intl
9 Mar
YUL3:45 p.m.Montreal Pierre Elliott Trudeau Intl
8h 59m
1 stop
STL11:44 p.m.Lambert-St Louis
C$ 522

WestJet flights from St. Louis to Region of Ontario

Our best WestJet deals on St. Louis to Region of Ontario flight tickets
WestJet
31 Jan
STL6:10 a.m.Lambert-St Louis
8h 43m
2 stops
YYZ3:53 p.m.Toronto Pearson Intl
1 Feb
YYZ7:45 a.m.Toronto Pearson Intl
13h 58m
1 stop
STL8:43 p.m.Lambert-St Louis
C$ 834
WestJet
14 Feb
STL5:50 p.m.Lambert-St Louis
4h 20m
1 stop
YUL11:10 p.m.Montreal Pierre Elliott Trudeau Intl
16 Feb
YUL6:00 p.m.Montreal Pierre Elliott Trudeau Intl
16h 06m
1 stop
STL9:06 a.m.Lambert-St Louis
C$ 914
WestJet
8 Feb
STL6:10 a.m.Lambert-St Louis
16h 25m
2 stops
YYZ11:35 p.m.Toronto Pearson Intl
14 Feb
YYZ12:11 p.m.Toronto Pearson Intl
9h 32m
1 stop
STL8:43 p.m.Lambert-St Louis
C$ 918

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Region of Ontario that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 96,600 searches. Data last updated 25 January 2026.
Use the filters below to find and compare flights from St. Louis to Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Thu 26/2

10:11 p.m.-6:43 a.m.

1 stop31h 32m

Toronto Pearson Intl

Wed 4/3

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

1 stop16h 17m

C$ 341

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Thu 26/2

10:11 p.m.-11:11 p.m.

2 stops24h 00m

Toronto Pearson Intl

Wed 4/3

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

1 stop16h 17m

C$ 348

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Tue 3/3

3:49 p.m.-2:20 p.m.

1 stop21h 31m

Toronto Pearson Intl

Tue 17/3

3:40 p.m.-10:37 a.m.

2 stops19h 57m

C$ 359

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 25/2

8:17 p.m.-2:20 p.m.

2 stops17h 03m

Toronto Pearson Intl

Wed 4/3

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

1 stop16h 17m

C$ 385

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 25/2

8:17 p.m.-2:20 p.m.

2 stops17h 03m

Toronto Pearson Intl

Thu 5/3

8:20 p.m.-7:02 a.m.

1 stop11h 42m

C$ 396

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Tue 17/2

6:00 a.m.-3:04 p.m.

1 stop8h 04m

Montreal Pierre Elliott Trudeau Intl

Fri 20/2

3:45 p.m.-10:13 a.m.

1 stop19h 28m

C$ 504

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Tue 17/2

10:37 a.m.-10:56 p.m.

2 stops11h 19m

Montreal Pierre Elliott Trudeau Intl

Fri 20/2

3:45 p.m.-10:13 a.m.

1 stop19h 28m

C$ 518

St. LouisLondon

STL - YXU

STLYXU

Lambert-St Louis

Mon 2/3

4:05 p.m.-9:21 p.m.

1 stop4h 16m

London

Wed 4/3

9:25 a.m.-3:29 p.m.

1 stop7h 04m

C$ 1,326

St. LouisLondon

STL - YXU

STLYXU

Lambert-St Louis

Mon 2/3

7:41 a.m.-9:21 p.m.

2 stops12h 40m

London

Wed 4/3

9:25 a.m.-9:05 p.m.

2 stops12h 40m

C$ 1,327

St. LouisLondon

STL - YXU

STLYXU

Lambert-St Louis

Mon 2/3

7:41 a.m.-9:21 p.m.

2 stops12h 40m

London

Wed 4/3

9:25 a.m.-3:29 p.m.

1 stop7h 04m

C$ 1,339

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Ontario from

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

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 Region of Ontario?

In general, June is the cheapest month to fly from St. Louis to Region of Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around C$ 497. If you are unable to visit Region of Ontario during the month of June, then departing from St. Louis during the month May is also very affordable. Most momondo users find prices during this month for around C$ 592.

What is the cheapest day to depart on your flight to Region of Ontario?

The cheapest day to depart from St. Louis to Region of Ontario is on a Sunday. Travellers who choose to depart for Region of Ontario on a Sunday will often find tickets for as low as C$ 464. The most expensive day to fly to Region of Ontario is Wednesday, with ticket prices averaging around C$ 891.

What is the cheapest time of day to depart on your flight to Region of Ontario?

Our most recent data shows that the best time of day to fly to Region of Ontario is in the morning. Flights from St. Louis to Region of Ontario during this time can be as low as C$ 575. If you have a flexible travel schedule, then try to avoid flying in the afternoon when prices are C$ 638 on average. Flights to Region of Ontario from St. Louis in the afternoon are generally more expensive because this time of day is more convenient for travellers’ schedules.

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

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

How far in advance should I book a flight to Region of Ontario?

You are more likely to see cheaper flights to Region of Ontario from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Region of Ontario for around C$ 731 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Region of Ontario from St. Louis for as low as C$ 303 on momondo.

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

There is only 1 cabin class available to choose from on Lambert-St Louis to Ontario 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 St. Louis to Region of Ontario flights?

You could potentially save up to 21% on your flight if you consider stops on a St. Louis to Region of Ontario flight.

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

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

Fastest flight time

1h 57m

Direct flights

Every day

Airports in Region of Ontario

123 airports
The fastest flight from St. Louis to Region of Ontario takes 1h 57m
Direct flights go from St. Louis to Region of Ontario every day.
There are 123 airports in Region of Ontario. From St. Louis there are direct flights to Montreal Pierre Elliott Trudeau Intl (YUL), Toronto Pearson Intl (YYZ).
Search flight deals

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

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

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

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

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Lambert-St Louis Airport to Ontario.

  • What documentation or ID do you need to fly to Ontario?

    The required travel and health documents for your Ontario trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Ontario. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

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

Best airlines flying from St. Louis to Region of Ontario

Compare and see reviews for airlines that fly from St. Louis to Region of Ontario with momondo
Airline
Rating
Free Cancellation
Price
Air CanadaPriceFrom C$ 298Free CancellationRating
7.1
10,655 reviews
Search Air Canada flights

Why use momondo?

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

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from St. Louis to Ontario for you.

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

Yes. momondo allows you to filter the results for St. Louis to Ontario flights to just show those with flexible booking policies.

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

momondo helps you find the best flight between St. Louis and Ontario by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

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

If you are not ready to book a flight from St. Louis to Ontario now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Ontario and let you know when they change.

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Find better results for your trip to Ontario

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