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

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

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

As of April 2026, 2 flights take off from St. Louis and land in Region of Ontario each day. The most common flight departure time for this route is 4:00p.m., with 100% of daily flights taking off in the afternoon.

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

As of April 2026, there are 20 flights per week flying from St. Louis to Region of Ontario. The most common day of the week flights depart is Mon, with 15% of flights taking off on this day.

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?

There is 1 operator available for flights from Lambert-St Louis Airport to Ontario as of April 2026.

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.

C$ 216 Cheap Flights from St. Louis to Ontario in 2026

1 adult

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Find the cheapest flights from St. Louis to Ontario

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

6:00 a.m. - 2:30 p.m.

STL

YYZ

7h 30m

1 stop

7:20 a.m. - 4:30 p.m.

YYZ

STL

10h 10m

1 stop

C$ 502American Airlines

Wed, 27 May - Wed, 3 Jun

6:00 a.m. - 2:30 p.m.

STL

YYZ

7h 30m

1 stop

1:15 p.m. - 8:30 p.m.

YYZ

STL

8h 15m

1 stop

C$ 538American Airlines

Wed, 27 May - Thu, 28 May

4:17 p.m. - 2:30 p.m.

STL

YYZ

21h 13m

1 stop

4:45 p.m. - 6:36 p.m.

YYZ

STL

26h 51m

2 stops

C$ 544Multiple Airlines

Wed, 10 Jun - Wed, 17 Jun

4:17 p.m. - 4:45 p.m.

STL

YYZ

23h 28m

1 stop

4:45 p.m. - 6:36 p.m.

YYZ

STL

26h 51m

2 stops

C$ 552Multiple Airlines

Wed, 10 Jun - Wed, 17 Jun

8:08 p.m. - 12:10 a.m.

STL

YYZ

27h 02m

2 stops

7:45 a.m. - 11:57 p.m.

YYZ

STL

17h 12m

1 stop

C$ 556Multiple Airlines

Wed, 27 May - Wed, 3 Jun

7:05 a.m. - 9:56 a.m.

STL

YYZ

1h 51mdirect

7:00 p.m. - 8:09 p.m.

YYZ

STL

2h 09mdirect

C$ 589Air Canada

Thu, 7 May - Sun, 10 May

1:05 p.m. - 7:58 p.m.

STL

YYZ

5h 53m

1 stop

7:00 p.m. - 8:09 p.m.

YYZ

STL

2h 09mdirect

C$ 593Air Canada

Thu, 7 May - Sun, 10 May

6:00 a.m. - 6:53 p.m.

STL

YUL

11h 53m

1 stop

9:30 a.m. - 8:39 p.m.

YUL

STL

12h 09m

1 stop

C$ 663Delta

Tue, 26 May - Tue, 2 Jun

6:00 a.m. - 6:53 p.m.

STL

YUL

11h 53m

1 stop

9:30 a.m. - 9:38 p.m.

YUL

STL

13h 08m

2 stops

C$ 676Delta

Tue, 26 May - Tue, 2 Jun

6:00 a.m. - 5:33 p.m.

STL

YXU

10h 33m

2 stops

5:10 a.m. - 12:11 p.m.

YXU

STL

8h 01m

2 stops

C$ 1,129United Airlines

Wed, 10 Jun - Wed, 17 Jun

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

27 May

STL6:00 a.m.Lambert-St Louis

10h 44m

1 stop

YYZ5:44 p.m.Toronto Pearson Intl

3 Jun

YYZ11:39 a.m.Toronto Pearson Intl

8h 41m

1 stop

STL7:20 p.m.Lambert-St Louis

C$ 502

American Airlines

27 May

STL6:00 a.m.Lambert-St Louis

7h 30m

1 stop

YYZ2:30 p.m.Toronto Pearson Intl

28 May

YYZ1:15 p.m.Toronto Pearson Intl

8h 15m

1 stop

STL8:30 p.m.Lambert-St Louis

C$ 538

American Airlines

27 May

STL7:00 a.m.Lambert-St Louis

9h 44m

1 stop

YYZ5:44 p.m.Toronto Pearson Intl

28 May

YYZ11:39 a.m.Toronto Pearson Intl

9h 51m

1 stop

STL8:30 p.m.Lambert-St Louis

C$ 575

Air Canada flights from St. Louis to Region of Ontario

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

Air Canada

7 May

STL7:05 a.m.Lambert-St Louis

1h 51m

YYZ9:56 a.m.Toronto Pearson Intl

10 May

YYZ7:00 p.m.Toronto Pearson Intl

2h 09m

STL8:09 p.m.Lambert-St Louis

C$ 589

Air Canada

7 May

STL1:05 p.m.Lambert-St Louis

5h 53m

1 stop

YYZ7:58 p.m.Toronto Pearson Intl

10 May

YYZ7:00 p.m.Toronto Pearson Intl

2h 09m

STL8:09 p.m.Lambert-St Louis

C$ 593

Air Canada

9 May

STL1:05 p.m.Lambert-St Louis

2h 35m

YUL4:40 p.m.Montreal Pierre Elliott Trudeau Intl

10 May

YUL6:30 p.m.Montreal Pierre Elliott Trudeau Intl

2h 55m

STL8:25 p.m.Lambert-St Louis

C$ 596

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 27/5

6:00 a.m.-2:30 p.m.

1 stop7h 30m

Toronto Pearson Intl

Wed 3/6

7:20 a.m.-4:30 p.m.

1 stop10h 10m

C$ 502

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 27/5

6:00 a.m.-2:30 p.m.

1 stop7h 30m

Toronto Pearson Intl

Thu 28/5

1:15 p.m.-8:30 p.m.

1 stop8h 15m

C$ 538

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 10/6

4:17 p.m.-2:30 p.m.

1 stop21h 13m

Toronto Pearson Intl

Wed 17/6

4:45 p.m.-6:36 p.m.

2 stops26h 51m

C$ 544

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 10/6

4:17 p.m.-4:45 p.m.

1 stop23h 28m

Toronto Pearson Intl

Wed 17/6

4:45 p.m.-6:36 p.m.

2 stops26h 51m

C$ 552

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 27/5

8:08 p.m.-12:10 a.m.

2 stops27h 02m

Toronto Pearson Intl

Wed 3/6

7:45 a.m.-11:57 p.m.

1 stop17h 12m

C$ 556

Quickest round-trip

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Thu 7/5

7:05 a.m.-9:56 a.m.

Nonstop1h 51m

Toronto Pearson Intl

Sun 10/5

7:00 p.m.-8:09 p.m.

Nonstop2h 09m

C$ 589

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Thu 7/5

1:05 p.m.-7:58 p.m.

1 stop5h 53m

Toronto Pearson Intl

Sun 10/5

7:00 p.m.-8:09 p.m.

Nonstop2h 09m

C$ 593

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Tue 26/5

6:00 a.m.-6:53 p.m.

1 stop11h 53m

Montreal Pierre Elliott Trudeau Intl

Tue 2/6

9:30 a.m.-8:39 p.m.

1 stop12h 09m

C$ 663

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Tue 26/5

6:00 a.m.-6:53 p.m.

1 stop11h 53m

Montreal Pierre Elliott Trudeau Intl

Tue 2/6

9:30 a.m.-9:38 p.m.

2 stops13h 08m

C$ 676

St. LouisLondon

STL - YXU

STLYXU

Lambert-St Louis

Wed 10/6

6:00 a.m.-5:33 p.m.

2 stops10h 33m

London

Wed 17/6

5:10 a.m.-12:11 p.m.

2 stops8h 01m

C$ 1,129

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 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

Prices

Airlines

Other information

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$ 551. If you are unable to visit Region of Ontario during the month of June, then departing from St. Louis during the month December is also very affordable. Most momondo users find prices during this month for around C$ 641.

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$ 463. The most expensive day to fly to Region of Ontario is Tuesday, with ticket prices averaging around C$ 637.

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$ 553. If you have a flexible travel schedule, then try to avoid flying at noon when prices are C$ 828 on average. Flights to Region of Ontario from St. Louis at noon 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

What cabin class options are available on St. Louis to Region of Ontario flights?

There is only 1 cabin class available to choose from on St. Louis to Region of 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 43% 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

Best price found	C$ 327
Fastest flight time	1h 51m
Direct flights	Every day
Airports in Region of Ontario	123 airports

The best one-way flight to Region of Ontario from St. Louis in the past 72 hours is C$ 327. The best round-trip flight deal from St. Louis to Region of Ontario found on momondo in the last 72 hours is C$ 284.

The fastest flight from St. Louis to Region of Ontario takes 1h 51m

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

Frequently asked questions about flying from St. Louis to Ontario

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?
There is 1 operator available for flights from Lambert-St Louis Airport to Ontario as of April 2026.
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?
momondo data reveals that the most frequently booked plane model on the route from St. Louis to Region of Ontario is Canadair (Bombardier) Regional Jet 900, representing 27.41% of all bookings. The subsequent popular models are Airbus A220-300 at 22.84%, Embraer 175 at 16.75%, and Boeing 787-8 Dreamliner at 13.71%.

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 Canada	PriceFrom C$ 323	Free Cancellation	Rating 7.1 10,974 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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Popular Cities in Ontario

Flights to Torontofrom C$ 186

Flights to Vancouverfrom C$ 115

Flights to Montrealfrom C$ 238

Flights to Calgaryfrom C$ 105

Flights to Ottawafrom C$ 261

Flights to Winnipegfrom C$ 197

Flights to Halifaxfrom C$ 175

Flights to Kelownafrom C$ 142

Flights to Saskatoonfrom C$ 215

Flights to Reginafrom C$ 202

Flights to St. John'sfrom C$ 249

Flights to Québec Cityfrom C$ 291

Cheap flights from St. Louis to Ontario from C$ 216

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 9/6. 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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American Airlines flights from St. Louis to Region of Ontario

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

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

What is the cheapest month to fly to Region of Ontario?

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

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

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

What cabin class options are available on St. Louis to Region of Ontario flights?

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

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

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

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

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

Best price found

Fastest flight time

Direct flights

Airports in Region of Ontario

Frequently asked questions about flying from St. Louis to 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

Why use momondo?

An easier way to manage your Region of Ontario 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 Ontario

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