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

As of March 2026, there are 14 flights per week flying from St. Louis to Region of Ontario. The most common day of the week flights depart is Mon, with 14% of flights taking off on this day.

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

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

What airlines fly to Region of Ontario?

Air Canada, United Airlines and American Airlines are the top three most popular airlines that fly to Region of Ontario from St. Louis according to our data. Air Canada is the first choice among our users, with 60% of people opting to fly with this airline when traveling to Region of Ontario. Keep in mind that there are 3 different airlines that fly to Region of Ontario on a routine basis, so you have a few additional options to choose from.

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

2 flights are operational daily from St. Louis to Region of Ontario as of March 2026. The most popular departure time for this route is 4:00PM, with 100% of flights per day taking off in the afternoon.

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 were last updated today.

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

The number of operators available for flights from Lambert-St Louis Airport to Ontario is 4 as of March 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 offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify 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.

$129 Cheap Flights from St. Louis to Ontario in 2026

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Find the cheapest flights from St. Louis to Ontario

Round-trip

One-way

Last minute

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Cheap round-trip flights

Enter your travel dates to find the best prices.

7:05 am - 6:33 pm

STL

YYZ

10h 28m

1 stop

1:15 pm - 10:17 pm

YYZ

STL

10h 02m

1 stop

$335American Airlines

Tue, Apr 14 - Wed, Apr 15

1:00 pm - 8:51 pm

STL

YOW

6h 51m

1 stop

7:00 am - 12:06 pm

YOW

STL

6h 06m

1 stop

$345Air Canada

Mon, May 4 - Sun, May 10

1:00 pm - 8:51 pm

STL

YOW

6h 51m

1 stop

2:35 pm - 8:25 pm

YOW

STL

6h 50m

1 stop

$358Air Canada

Thu, May 14 - Sun, May 17

1:00 pm - 8:51 pm

STL

YOW

6h 51m

1 stop

7:00 am - 12:06 pm

YOW

STL

6h 06m

1 stop

$363Air Canada

Wed, May 13 - Mon, May 18

4:59 pm - 12:30 am

STL

YUL

30h 31m

1 stop

8:00 am - 6:50 am

YUL

STL

47h 50m

2 stops

$366Multiple Airlines

Mon, Apr 20 - Mon, Apr 27

8:03 pm - 11:44 am

STL

YUL

14h 41m

1 stop

12:30 pm - 8:09 pm

YUL

STL

8h 39m

1 stop

$373American Airlines

Wed, Apr 8 - Sat, Apr 11

4:59 pm - 12:30 am

STL

YUL

30h 31m

1 stop

8:00 am - 6:50 am

YUL

STL

47h 50m

2 stops

$374Multiple Airlines

Mon, Apr 20 - Mon, Apr 27

4:59 pm - 12:30 am

STL

YUL

30h 31m

1 stop

8:00 am - 6:50 am

YUL

STL

47h 50m

2 stops

$378Multiple Airlines

Mon, Apr 20 - Mon, Apr 27

9:10 am - 5:07 pm

STL

YOW

6h 57m

1 stop

6:25 am - 10:45 am

YOW

STL

5h 20m

1 stop

$392United Airlines

Wed, Apr 15 - Sun, Apr 19

6:30 am - 4:38 pm

STL

YOW

9h 08m

2 stops

5:25 pm - 11:11 pm

YOW

STL

6h 46m

1 stop

$402United Airlines

Wed, Apr 15 - Sun, Apr 19

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

Apr 14

STL7:05 amLambert-St Louis

10h 28m

1 stop

YYZ6:33 pmToronto Pearson Intl

Apr 15

YYZ1:15 pmToronto Pearson Intl

10h 02m

1 stop

STL10:17 pmLambert-St Louis

$335

American Airlines

Apr 8

STL8:03 pmLambert-St Louis

14h 41m

1 stop

YUL11:44 amMontreal Pierre Elliott Trudeau Intl

Apr 11

YUL12:30 pmMontreal Pierre Elliott Trudeau Intl

8h 39m

1 stop

STL8:09 pmLambert-St Louis

$373

American Airlines

Apr 8

STL8:03 pmLambert-St Louis

14h 41m

1 stop

YUL11:44 amMontreal Pierre Elliott Trudeau Intl

Apr 11

YUL1:03 pmMontreal Pierre Elliott Trudeau Intl

11h 43m

2 stops

STL11:46 pmLambert-St Louis

$383

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

May 4

STL1:00 pmLambert-St Louis

6h 51m

1 stop

YOW8:51 pmOttawa

May 10

YOW7:00 amOttawa

6h 06m

1 stop

STL12:06 pmLambert-St Louis

$345

Air Canada

May 14

STL1:00 pmLambert-St Louis

6h 51m

1 stop

YOW8:51 pmOttawa

May 17

YOW2:35 pmOttawa

6h 50m

1 stop

STL8:25 pmLambert-St Louis

$358

Air Canada

May 13

STL1:00 pmLambert-St Louis

6h 51m

1 stop

YOW8:51 pmOttawa

May 18

YOW7:00 amOttawa

6h 06m

1 stop

STL12:06 pmLambert-St Louis

$363

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Tue 4/14

7:05 am-6:33 pm

1 stop10h 28m

Toronto Pearson Intl

Wed 4/15

1:15 pm-10:17 pm

1 stop10h 02m

$335

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 5/4

1:00 pm-8:51 pm

1 stop6h 51m

Ottawa

Sun 5/10

7:00 am-12:06 pm

1 stop6h 06m

$345

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Thu 5/14

1:00 pm-8:51 pm

1 stop6h 51m

Ottawa

Sun 5/17

2:35 pm-8:25 pm

1 stop6h 50m

$358

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 5/13

1:00 pm-8:51 pm

1 stop6h 51m

Ottawa

Mon 5/18

7:00 am-12:06 pm

1 stop6h 06m

$363

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Mon 4/20

4:59 pm-12:30 am

1 stop30h 31m

Montreal Pierre Elliott Trudeau Intl

Mon 4/27

8:00 am-6:50 am

2 stops47h 50m

$366

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Wed 4/8

8:03 pm-11:44 am

1 stop14h 41m

Montreal Pierre Elliott Trudeau Intl

Sat 4/11

12:30 pm-8:09 pm

1 stop8h 39m

$373

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Mon 4/20

4:59 pm-12:30 am

1 stop30h 31m

Montreal Pierre Elliott Trudeau Intl

Mon 4/27

8:00 am-6:50 am

2 stops47h 50m

$374

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Mon 4/20

4:59 pm-12:30 am

1 stop30h 31m

Montreal Pierre Elliott Trudeau Intl

Mon 4/27

8:00 am-6:50 am

2 stops47h 50m

$378

Quickest round-trip

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 4/15

9:10 am-5:07 pm

1 stop6h 57m

Ottawa

Sun 4/19

6:25 am-10:45 am

1 stop5h 20m

$392

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 4/15

6:30 am-4:38 pm

2 stops9h 08m

Ottawa

Sun 4/19

5:25 pm-11:11 pm

1 stop6h 46m

$402

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?

The month of June is, on average, the cheapest month to fly to Region of Ontario from St. Louis, with most prices found around $306. If you aren’t able to travel during the month of June, then book flights to Region of Ontario from St. Louis during March instead. Flights to Region of Ontario in March, while not as cheap as those in June, still average around $349.

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

According to our data, Tuesday is the cheapest day to fly to Region of Ontario from St. Louis. The lowest ticket price found for a Tuesday departure recently was $790. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. Flights from St. Louis to Region of Ontario on a Friday will generally be more expensive and average around $955. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

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

According to our data, the cheapest time of day to fly to Region of Ontario is in the afternoon. momondo users have found flights departing from St. Louis to Region of Ontario in the afternoon for as low as $854. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights at noon are often more expensive with an average ticket price of $1,073.

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 Lambert-St Louis to Ontario flights?

There are 4 cabin classes 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 47% 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	$383
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 $383. The best round-trip flight deal from St. Louis to Region of Ontario found on momondo in the last 72 hours is $730.

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

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 were last updated today.
How many operators does momondo search for flights from Lambert-St Louis Airport to Ontario?
The number of operators available for flights from Lambert-St Louis Airport to Ontario is 4 as of March 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 offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify 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 Embraer 175, representing 34.68% of all bookings. The subsequent popular models are Canadair (Bombardier) Regional Jet 900 at 15.32%, Boeing 787-8 Dreamliner at 15.32%, and Airbus A220-300 at 12.90%.

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 $139	Free Cancellation	Rating 7.1 10,800 reviews	Search Air Canada flights
United Airlines	PriceFrom $199	Free Cancellation	Rating 7.4 9,409 reviews	Search United Airlines flights
American Airlines	PriceFrom $270	Free Cancellation	Rating 7.1 11,414 reviews	Search American Airlines flights

Why use momondo?

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

It is quick and easy to find St. Louis to Ontario 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 Ontario that suits you.

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

Yes. All flights to Ontario from St. Louis on momondo can be compared and filtered by various policies on offer, including flexible booking.

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

Once you have performed a search for St. Louis to Ontario 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 St. Louis to Ontario right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Ontario, momondo offers a useful price alert feature which will track prices for flights to Ontario from St. Louis and alert you when they change.

An easier way to manage your Region of Ontario trip

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Popular cities in Ontario

Flights to Torontofrom $136

Flights to Vancouverfrom $107

Flights to Montrealfrom $171

Flights to Calgaryfrom $184

Flights to Ottawafrom $173

Flights to Halifaxfrom $264

Flights to Winnipegfrom $228

Flights to Québec Cityfrom $313

Flights to Kelownafrom $182

Flights to Saskatoonfrom $211

Flights to St. John'sfrom $366

Flights to Reginafrom $245

Cheap flights from St. Louis to Ontario from $129

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 3/31. 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

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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 Lambert-St Louis to 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?

What airlines fly to Region of 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

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

Popular cities in Ontario

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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