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Cheap flights from Montreal to St. Louis from $241

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Montreal to St. Louis departing on 9/10. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Montreal to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
American Airlines Logo
12:31 pm - 12:27 amYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
12h 56m1 stop Chicago O'Hare Intl
American Airlines Logo
5:18 pm - 11:44 amSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
17h 26m1 stop Chicago O'Hare Intl
$452American Airlines
Mon, Sep 21 - Mon, Sep 28
American Airlines Logo
5:34 pm - 8:24 amYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
15h 50m1 stop Chicago O'Hare Intl
American Airlines Logo
8:06 pm - 11:43 amSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
14h 37m1 stop Chicago O'Hare Intl
$462American Airlines
Tue, Sep 1 - Sat, Sep 5
American Airlines Logo
12:30 pm - 8:57 pmYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
9h 27m1 stop Chicago O'Hare Intl
American Airlines Logo
5:27 pm - 11:44 amSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
17h 17m1 stop Chicago O'Hare Intl
$471American Airlines
Thu, Oct 15 - Mon, Oct 19
American Airlines Logo
12:30 pm - 8:57 pmYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
9h 27m1 stop Chicago O'Hare Intl
American Airlines Logo
5:27 pm - 11:44 amSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
17h 17m1 stop Chicago O'Hare Intl
$473American Airlines
Thu, Oct 15 - Mon, Oct 19
American Airlines Logo
12:31 pm - 12:27 amYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
12h 56m1 stop Chicago O'Hare Intl
American Airlines Logo
5:18 pm - 11:44 amSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
17h 26m1 stop Chicago O'Hare Intl
$474American Airlines
Mon, Sep 21 - Mon, Sep 28
Air Canada Logo
4:55 pm - 6:42 pmYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
2h 47mnonstop
Air Canada Logo
12:10 pm - 3:42 pmSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
2h 32mnonstop
$476Air Canada
Fri, Sep 4 - Mon, Sep 7
American Airlines Logo
5:34 pm - 8:24 amYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
15h 50m1 stop Chicago O'Hare Intl
American Airlines Logo
8:07 pm - 11:43 amSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
14h 36m1 stop Chicago O'Hare Intl
$478American Airlines
Fri, Sep 4 - Mon, Sep 7
American Airlines Logo
12:30 pm - 8:57 pmYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
9h 27m1 stop Chicago O'Hare Intl
American Airlines Logo
5:27 pm - 11:44 amSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
17h 17m1 stop Chicago O'Hare Intl
$479American Airlines
Thu, Oct 15 - Mon, Oct 19
American Airlines Logo
12:30 pm - 12:14 amYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
12h 44m1 stop Chicago O'Hare Intl
American Airlines Logo
8:07 pm - 11:43 amSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
14h 36m1 stop Chicago O'Hare Intl
$479American Airlines
Tue, Aug 25 - Wed, Aug 26
Air Canada Logo
4:55 pm - 6:42 pmYUL  Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis
2h 47mnonstop
Air Canada Logo
12:10 pm - 3:42 pmSTL  Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl
2h 32mnonstop
$486Air Canada
Fri, Aug 28 - Sun, Aug 30

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United Airlines flights from Montreal to St. Louis

Our best United Airlines deals on Montreal to St. Louis flight tickets
United Airlines
Aug 24
YUL9:45 amMontreal Pierre Elliott Trudeau Intl
6h 53m
1 stop
STL3:38 pmLambert-St Louis
Aug 24
STL6:54 pmLambert-St Louis
14h 46m
1 stop
YUL10:40 amMontreal Pierre Elliott Trudeau Intl
$510
United Airlines
Oct 27
YUL4:45 pmMontreal Pierre Elliott Trudeau Intl
5h 55m
1 stop
STL9:40 pmLambert-St Louis
Oct 31
STL3:15 pmLambert-St Louis
5h 02m
1 stop
YUL9:17 pmMontreal Pierre Elliott Trudeau Intl
$515
United Airlines
Aug 24
YUL9:45 amMontreal Pierre Elliott Trudeau Intl
6h 53m
1 stop
STL3:38 pmLambert-St Louis
Aug 26
STL6:00 amLambert-St Louis
7h 40m
2 stops
YUL2:40 pmMontreal Pierre Elliott Trudeau Intl
$516

Air Canada flights from Montreal to St. Louis

Our best Air Canada deals on Montreal to St. Louis flight tickets
Air Canada
Sep 4
YUL4:55 pmMontreal Pierre Elliott Trudeau Intl
2h 47m
STL6:42 pmLambert-St Louis
Sep 7
STL12:10 pmLambert-St Louis
2h 32m
YUL3:42 pmMontreal Pierre Elliott Trudeau Intl
$476
Air Canada
Aug 28
YUL4:55 pmMontreal Pierre Elliott Trudeau Intl
2h 47m
STL6:42 pmLambert-St Louis
Aug 30
STL12:10 pmLambert-St Louis
2h 32m
YUL3:42 pmMontreal Pierre Elliott Trudeau Intl
$486
Air Canada
Sep 4
YUL4:55 pmMontreal Pierre Elliott Trudeau Intl
2h 47m
STL6:42 pmLambert-St Louis
Sep 7
STL2:40 pmLambert-St Louis
4h 47m
1 stop
YUL8:27 pmMontreal Pierre Elliott Trudeau Intl
$489

momondo Fare Finder

 
Customize your flight search to find flights from Montreal to St. Louis 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 832,500 searches. Data last updated August 8, 2026.
Use the filters below to find and compare flights from Montreal to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 9/21

12:31 pm-12:27 am

1 stop12h 56m

Lambert-St Louis

Mon 9/28

5:18 pm-11:44 am

1 stop17h 26m

$452

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Tue 9/1

5:34 pm-8:24 am

1 stop15h 50m

Lambert-St Louis

Sat 9/5

8:06 pm-11:43 am

1 stop14h 37m

$462

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 10/15

12:30 pm-8:57 pm

1 stop9h 27m

Lambert-St Louis

Mon 10/19

5:27 pm-11:44 am

1 stop17h 17m

$471

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 10/15

12:30 pm-8:57 pm

1 stop9h 27m

Lambert-St Louis

Mon 10/19

5:27 pm-11:44 am

1 stop17h 17m

$473

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 9/21

12:31 pm-12:27 am

1 stop12h 56m

Lambert-St Louis

Mon 9/28

5:18 pm-11:44 am

1 stop17h 26m

$474
Quickest round-trip

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Fri 9/4

4:55 pm-6:42 pm

Nonstop2h 47m

Lambert-St Louis

Mon 9/7

12:10 pm-3:42 pm

Nonstop2h 32m

$476

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Fri 9/4

5:34 pm-8:24 am

1 stop15h 50m

Lambert-St Louis

Mon 9/7

8:07 pm-11:43 am

1 stop14h 36m

$478

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 10/15

12:30 pm-8:57 pm

1 stop9h 27m

Lambert-St Louis

Mon 10/19

5:27 pm-11:44 am

1 stop17h 17m

$479

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Tue 8/25

12:30 pm-12:14 am

1 stop12h 44m

Lambert-St Louis

Wed 8/26

8:07 pm-11:43 am

1 stop14h 36m

$479

MontrealSt. Louis

YUL Montreal Pierre Elliott Trudeau Intl - STL Lambert-St Louis

YULSTL

Montreal Pierre Elliott Trudeau Intl

Fri 8/28

4:55 pm-6:42 pm

Nonstop2h 47m

Lambert-St Louis

Sun 8/30

12:10 pm-3:42 pm

Nonstop2h 32m

$486

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 St. Louis from

How to get the cheapest flight ticket from Montreal 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

What is the cheapest month to fly to St. Louis?

In general, August is the cheapest month to fly from Montreal to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $511. The month of May is another great option to travel to St. Louis, with average flight prices from Montreal averaging around $548.

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 Thursday when prices can be found for as low as $567. 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 Friday because tickets tend to average around $690. 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 Montreal to Lambert-St Louis flight route?

Fly from Montreal Pierre Elliott Trudeau Intl to Lambert-St Louis for the best Montreal - Lambert-St Louis flight prices

What cabin class options are available on Montreal to St. Louis flights?

There is only 1 cabin class available to choose from on Montreal to 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 Montreal to St. Louis flights?

You could potentially save up to 6% on your flight if you consider stops on a Montreal to St. Louis flight.

When to book flights from Montreal to St. Louis

Are you open to changing your travel dates? Check out the ideal times to fly from Montreal to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Montreal to St. Louis (YMQ to STL) flight deals and tips

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

Fastest flight time

2h 46m

Direct flights

Every day

Airports in St. Louis

1 airport
The fastest flight from Montreal to St. Louis takes 2h 46m
Direct flights go from Montreal to St. Louis every day.
There is 1 airport in St. Louis. From Montreal there are direct flights to Lambert-St Louis (STL).
Search flight deals

Frequently asked questions about flying from Montreal to St. Louis

  • How far is Montreal to Lambert-St Louis by plane?

    A flight from Montreal to Lambert-St Louis will travel around 973.0 mi. Typically, this will take 2h 46m by plane in normal conditions.

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

    Prices for flights from Montreal to Lambert-St Louis Airport were last updated today.

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

  • How old do you have to be to fly from Montreal 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 Montreal 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 Montreal to St. Louis?

Best airlines flying from Montreal to St. Louis

Compare and see reviews for airlines that fly from Montreal to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
Air CanadaPriceFrom $498Free CancellationRating
7.1
11,450 reviews
Search Air Canada flights

  • Air Canada Flights From Montreal to St. Louis

    The lowest priced Air Canada flight from Montreal to St. Louis from the last 72 hours was $498. Generally, Air Canada has 7 flights on this route every week with an average price of $567. Air Canada is rated 7.1/10 by our users.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Fairview Heights
Hermann
St. Peters
Maryland Heights
Florissant
Collinsville
Alton
O'Fallon
Clayton
Farmington
Fenton
Wentzville
Festus
Eureka
Edwardsville
Litchfield
Grafton
Shrewsbury

Why use momondo?

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

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

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

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

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

Once all potential Montreal 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 Montreal to St. Louis right now. Can momondo alert me if prices change?

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

An easier way to manage your St. Louis trip

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