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

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

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

As of December 2025, 2 flights take off from Region of Ontario and land in St. Louis each day. The most common flight departure time for this route is 2:00PM, with 100% of daily flights 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 December 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?

Flight times from Region of Ontario to St. Louis vary, but if you’re flying out of Toronto and flying into St. Louis (one of the most popular routes), then the duration is 2h 14m on average. Another popular route from Region of Ontario to St. Louis is flying from Ottawa to St. Louis, which will take roughly 6h 47m. Keep in mind that layovers or delays could extend your travel time.

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 refresh daily.

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

As of December 2025, there are 2 operators available to choose from 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?

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 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 required for your trip to Lambert-St Louis Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Lambert-St Louis Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

$142 Cheap Flights from Ontario to St. Louis in 2025/26

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Find the cheapest flights from Ontario to St. Louis

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7:10 am - 10:34 pm

YYZ

STL

16h 24m1 stop

5:11 pm - 2:20 pm

STL

YYZ

20h 09m1 stop

$228Multiple Airlines

ה', ינו' 15 - א', ינו' 18

7:10 am - 10:34 pm

YYZ

STL

16h 24m1 stop

5:42 pm - 2:05 pm

STL

YYZ

19h 23m1 stop

$278Multiple Airlines

ש', ינו' 17 - ש', ינו' 24

4:15 pm - 6:51 am

YOW

STL

39h 36m2 stops

5:42 pm - 5:13 pm

STL

YOW

22h 31m1 stop

$282Multiple Airlines

ב', פב' 2 - ב', פב' 9

3:40 pm - 6:51 am

YYZ

STL

40h 11m2 stops

5:42 pm - 2:05 pm

STL

YYZ

19h 23m1 stop

$287Multiple Airlines

ש', ינו' 17 - ש', ינו' 24

5:55 pm - 11:59 pm

YOW

STL

7h 04m1 stop

3:11 pm - 9:18 pm

STL

YOW

5h 07m1 stop

$309United Airlines

ב', פב' 2 - ב', פב' 9

2:15 pm - 7:27 pm

YOW

STL

6h 12m1 stop

7:00 am - 1:32 pm

STL

YOW

5h 32m1 stop

$311United Airlines

ד', ינו' 21 - ש', ינו' 24

11:30 am - 9:15 pm

YYZ

STL

10h 45m1 stop

6:00 am - 4:03 pm

STL

YYZ

9h 03m1 stop

$319American Airlines

ג', פב' 3 - ד', פב' 4

3:50 pm - 10:20 am

YUL

STL

19h 30m1 stop

6:00 am - 3:08 pm

STL

YUL

8h 08m1 stop

$329American Airlines

ב', פב' 2 - ב', פב' 9

5:40 am - 4:42 pm

YOW

STL

12h 02m2 stops

3:58 pm - 12:39 am

STL

YOW

7h 41m2 stops

$378Delta

ה', מרץ 26 - ב', מרץ 30

7:00 am - 2:49 pm

YUL

STL

8h 49m1 stop

6:35 am - 12:12 pm

STL

YUL

4h 37m1 stop

$524Delta

ה', ינו' 22 - ב', ינו' 26

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

Feb 2

YOW5:55 pmOttawa

7h 04m

1 stop

STL11:59 pmLambert-St Louis

Feb 9

STL3:11 pmLambert-St Louis

5h 07m

1 stop

YOW9:18 pmOttawa

$309

Find similar

United Airlines

Jan 21

YOW2:15 pmOttawa

6h 12m

1 stop

STL7:27 pmLambert-St Louis

Jan 24

STL7:00 amLambert-St Louis

5h 32m

1 stop

YOW1:32 pmOttawa

$311

Find similar

United Airlines

Jan 21

YOW2:15 pmOttawa

6h 12m

1 stop

STL7:27 pmLambert-St Louis

Jan 24

STL8:30 amLambert-St Louis

4h 57m

1 stop

YOW2:27 pmOttawa

$312

Find similar

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

Feb 3

YYZ11:30 amToronto Pearson Intl

10h 45m

1 stop

STL9:15 pmLambert-St Louis

Feb 4

STL6:00 amLambert-St Louis

9h 03m

1 stop

YYZ4:03 pmToronto Pearson Intl

$319

Find similar

American Airlines

Feb 2

YUL3:50 pmMontreal Pierre Elliott Trudeau Intl

19h 30m

1 stop

STL10:20 amLambert-St Louis

Feb 9

STL6:00 amLambert-St Louis

8h 08m

1 stop

YUL3:08 pmMontreal Pierre Elliott Trudeau Intl

$329

Find similar

American Airlines

Feb 2

YUL3:50 pmMontreal Pierre Elliott Trudeau Intl

19h 30m

1 stop

STL10:20 amLambert-St Louis

Feb 9

STL11:05 amLambert-St Louis

10h 54m

2 stops

YUL10:59 pmMontreal Pierre Elliott Trudeau Intl

$339

Find similar

Fly from

Fly to

Route

Depart

Return

Price

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

ה' 1/15

7:10 am-10:34 pm

1 stop16h 24m

Lambert-St Louis

א' 1/18

5:11 pm-2:20 pm

1 stop20h 09m

$228

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

ש' 1/17

7:10 am-10:34 pm

1 stop16h 24m

Lambert-St Louis

ש' 1/24

5:42 pm-2:05 pm

1 stop19h 23m

$278

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

ב' 2/2

4:15 pm-6:51 am

2 stops39h 36m

Lambert-St Louis

ב' 2/9

5:42 pm-5:13 pm

1 stop22h 31m

$282

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

ש' 1/17

3:40 pm-6:51 am

2 stops40h 11m

Lambert-St Louis

ש' 1/24

5:42 pm-2:05 pm

1 stop19h 23m

$287

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

ב' 2/2

5:55 pm-11:59 pm

1 stop7h 04m

Lambert-St Louis

ב' 2/9

3:11 pm-9:18 pm

1 stop5h 07m

$309

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

ד' 1/21

2:15 pm-7:27 pm

1 stop6h 12m

Lambert-St Louis

ש' 1/24

7:00 am-1:32 pm

1 stop5h 32m

$311

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

ג' 2/3

11:30 am-9:15 pm

1 stop10h 45m

Lambert-St Louis

ד' 2/4

6:00 am-4:03 pm

1 stop9h 03m

$319

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

ב' 2/2

3:50 pm-10:20 am

1 stop19h 30m

Lambert-St Louis

ב' 2/9

6:00 am-3:08 pm

1 stop8h 08m

$329

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

ה' 3/26

5:40 am-4:42 pm

2 stops12h 02m

Lambert-St Louis

ב' 3/30

3:58 pm-12:39 am

2 stops7h 41m

$378

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

ה' 1/22

7:00 am-2:49 pm

1 stop8h 49m

Lambert-St Louis

ב' 1/26

6:35 am-12:12 pm

1 stop4h 37m

$524

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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?

In general, June is the cheapest month to fly from Region of Ontario to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $372. The month of August is another great option to travel to St. Louis, with average flight prices from Region of Ontario averaging around $397.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Saturday when prices can be found for as low as $405. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $542. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Region of Ontario in the morning is the least expensive time of day to depart. momondo users have found prices as low as $326 when looking at flights departing in the morning. At noon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $491 per ticket.

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 $472 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 $360 on momondo.

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

There are 3 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?

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	$1,089
Fastest flight time	2h 14m
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 $1,089

The fastest flight from Region of Ontario to St. Louis takes 2h 14m

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 refresh daily.
How many operators does momondo search for flights from Ontario to Lambert-St Louis Airport?
As of December 2025, there are 2 operators available to choose from 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?
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 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 required for your trip to Lambert-St Louis Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Lambert-St Louis Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.
What is the most popular plane model from Region of Ontario to St. Louis?
Based on momondo bookings for flights between Region of Ontario and St. Louis, the leading plane model is Embraer 175, making up 57.28% of the total bookings. Other popular models include Canadair (Bombardier) Regional Jet 900 with 23.30%, Airbus A319 with 5.83%, and Airbus A320-100/200 with 5.83%.

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 $324	Free Cancellation	Rating 7.1 10,549 reviews		Search Air Canada flights

St. Charles

Chesterfield

Hermann

Fairview Heights

Maryland Heights

O'Fallon

Florissant

Fenton

St. Peters

Wentzville

Collinsville

Alton

Farmington

Clayton

Festus

Glencoe

Eureka

Edwardsville

Litchfield

Shrewsbury

Why use momondo?

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

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Ontario to St. Louis. Millions of users trust and use momondo every year so you are in good hands.

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 all potential Ontario to St. Louis flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

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

Price alerts on flights to St. Louis from Ontario are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

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Cheap flights from Ontario to St. Louis from $142

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 2/3. 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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United Airlines flights from Region of Ontario to St. Louis

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American Airlines flights from Region of Ontario to St. Louis

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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?

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 3 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?

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?

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

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

As of December 2025, 2 flights take off from Region of Ontario and land in St. Louis each day. The most common flight departure time for this route is 2:00PM, with 100% of daily flights 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 December 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

Traveling 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.

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