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$233+ Cheap flights from Pierre Elliott Trudeau Intl (YUL) to St. Louis (STL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/2. Fares are subject to change and may not be available on all flights or dates of travel.
YUL — STL
Aug 25 — Sep 11
Tue 8/25
Tue 9/1
1 adult, Economy
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Cheap flight deals from Pierre Elliott Trudeau Intl to St. Louis

Cheapest flights from Pierre Elliott Trudeau Intl to St. Louis
Explore the most affordable flight options available from Pierre Elliott Trudeau Intl to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 26, 2026.

This American Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/1512:31 pm
YUL
-
STL
1 stop12h 56m
American Airlines
Sat 9/197:27 am
STL
-
YUL
1 stop8h 26m
American Airlines
Deal found 7/23$407
This American Airlines deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/1512:30 pm
YUL
-
STL
1 stop9h 38m
American Airlines
Mon 10/195:27 pm
STL
-
YUL
1 stop17h 17m
American Airlines
Deal found 7/24$445
This American Airlines deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/25:34 pm
YUL
-
STL
1 stop17h 46m
American Airlines
Wed 10/145:00 am
STL
-
YUL
1 stop10h 52m
American Airlines
Deal found 7/25$446
This American Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/225:34 pm
YUL
-
STL
1 stop17h 46m
American Airlines
Sat 9/267:27 am
STL
-
YUL
1 stop8h 26m
American Airlines
Deal found 7/23$454
This United Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/228:30 am
YUL
-
STL
2 stops14h 30m
United Airlines
Tue 9/299:04 am
STL
-
YUL
1 stop8h 51m
United Airlines
Deal found 7/23$483
This United Airlines deal was found by Cheapflights users on 7/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/199:15 am
YUL
-
STL
2 stops11h 46m
United Airlines
Mon 9/2112:59 pm
STL
-
YUL
1 stop20h 41m
United Airlines
Deal found 7/22$484
This United Airlines deal was found by Cheapflights users on 7/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/276:10 am
YUL
-
STL
1 stop9h 47m
United Airlines
Mon 8/315:30 pm
STL
-
YUL
1 stop17h 29m
United Airlines
Deal found 7/21$489
This United Airlines deal was found by Cheapflights users on 7/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/151:15 pm
YUL
-
STL
1 stop9h 06m
United Airlines
Mon 10/195:36 pm
STL
-
YUL
1 stop19h 42m
United Airlines
Deal found 7/22$490
This United Airlines deal was found by Cheapflights users on 7/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/189:45 am
YUL
-
STL
1 stop27h 18m
United Airlines
Mon 9/2112:59 pm
STL
-
YUL
1 stop22h 01m
United Airlines
Deal found 7/21$491

Find flight deals from Pierre Elliott Trudeau Intl to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Pierre Elliott Trudeau Intl (YUL) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated July 26, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$407
(American Airlines)

One-way from

$233
(American Airlines)

Popular in

January

Cheapest in

November

Average price

$575

Good one-way deal

$305 or less
Provider with most accurate pricing for Montreal Pierre Elliott Trudeau Intl-Lambert-St Louis flight deals.
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Provider most trusted by Cheapflights users for Montreal Pierre Elliott Trudeau Intl-Lambert-St Louis flights.
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From Montreal Pierre Elliott Trudeau Intl to Lambert-St Louis
Search Deals
One-way flight from Montreal Pierre Elliott Trudeau Intl to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 15% potential increase in price ($113 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($24 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 2026
Search Deals
Price to beat on a one-way flight from Montreal Pierre Elliott Trudeau Intl to Lambert-St Louis.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Pierre Elliott Trudeau Intl 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, Cheapflights users made 2,558,603 searches. Data last updated July 26, 2026.
Use the filters below to find and compare flights from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Tue 9/15

9:15 am-10:00 pm

2 stops13h 45m

Lambert-St Louis

Sat 9/19

12:59 pm-11:23 am

2 stops21h 24m

$483

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sat 9/26

9:45 am-9:21 pm

1 stop12h 36m

Lambert-St Louis

Tue 9/29

8:00 am-5:30 pm

1 stop8h 30m

$483

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Tue 9/22

6:10 am-3:38 pm

1 stop10h 28m

Lambert-St Louis

Wed 9/30

8:00 am-6:55 pm

1 stop9h 55m

$483

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sat 9/19

9:15 am-8:01 pm

2 stops11h 46m

Lambert-St Louis

Mon 9/21

12:59 pm-10:40 am

1 stop20h 41m

$484

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 8/27

6:10 am-2:57 pm

1 stop9h 47m

Lambert-St Louis

Mon 8/31

5:30 pm-11:59 am

1 stop17h 29m

$489

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 10/15

1:15 pm-9:21 pm

1 stop9h 06m

Lambert-St Louis

Mon 10/19

5:36 pm-2:18 pm

1 stop19h 42m

$490

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Fri 9/18

9:45 am-12:03 pm

1 stop27h 18m

Lambert-St Louis

Mon 9/21

12:59 pm-12:00 pm

1 stop22h 01m

$491
Quickest round-trip

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 10/15

4:55 pm-6:41 pm

Nonstop2h 46m

Lambert-St Louis

Mon 10/19

12:10 pm-3:41 pm

Nonstop2h 31m

$501
Cheapest one-way

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 9/2

12:30 pm-12:14 am

1 stop12h 44m

$233

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 10/22

9:00 am-9:40 am

3 stops25h 40m

$242

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/22

Showing 1-10 of 18 resultsSorted by cheapest first
1
2
  • Most accurate provider: When it comes to deals on Montreal Pierre Elliott Trudeau Intl Airport-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Montreal Pierre Elliott Trudeau Intl Airport-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Montreal Pierre Elliott Trudeau Intl Airport-St. Louis flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Montreal Pierre Elliott Trudeau Intl Airport-St. Louis flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Montreal Pierre Elliott Trudeau Intl Airport-St. Louis flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Pierre Elliott Trudeau Intl to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Pierre Elliott Trudeau Intl with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis

What is the cheapest month to book a flight from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis?

Currently, November is the cheapest month in which you can book a flight from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis (average of $542). Flying from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis in January is currently the most expensive (average of $889). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from YUL to STL?

Find hourly flight availability from Pierre Elliott Trudeau Intl to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 26, 2026.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis as you normally would.

How much does it cost to fly round-trip from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis?

Airfare is below average for this route at the moment.

Montreal Pierre Elliott Trudeau Intl Airport to St. Louis flights typically cost between $470 and $726 in September.
The cheapest round-trip price found within the last 5 days was $407 on American Airlines (Sep 15-Sep 19).

The best insider tips for Montreal Pierre Elliott Trudeau Intl Airport to St. Louis flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Montreal Pierre Elliott Trudeau Intl Airport to St. Louis trip
Our travel experts
John Walton

John Walton

Expert on YUL

Independent aviation journalist John Walton took his first flight at eight weeks old and hasn’t stopped travelling since. A world-renowned expert in airlines and the passenger experience, he writes in depth on aviation, is a resident expert on travel in Japan and France, and offers a uniquely queer perspective on travelling the world.

Read more
Taryn White

Taryn White

Expert on STL

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Read more

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Louis. Reviews last updated July 26, 2026.
Peruse reviews from past customers who have flown with Air Canada from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Air Canada
7.1
Good
11,387 reviews

Overall

7.1

Boarding

7.3

Food

6.3

Comfort

7.1

Entertainment

6.8

Crew

7.8

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2024

YUL - FLL

Poor communication skills. Language is mostly French. Very little in translation. Hard to hear. No entertainment system
Air Canada
7.1
Good
11,387 reviews
Air Canada
7.1
Good
11,387 reviews

Overall

7.1

Boarding

7.3

Food

6.3

Comfort

7.1

Entertainment

6.8

Crew

7.8

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2024

YUL - FLL

Poor communication skills. Language is mostly French. Very little in translation. Hard to hear. No entertainment system

Related info for your journey

Find useful and relevant information for your journey from Pierre Elliott Trudeau Intl to St. Louis. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to St. Louis from Montreal Pierre Elliott Trudeau Intl?

    For a flight from Montreal Pierre Elliott Trudeau Intl to St. Louis, you will be flying into Lambert-St Louis. Lambert-St Louis (STL) is just 12.7 mi from the center of the city. Lambert-St Louis is the only St. Louis airport and it handles 2 inbound flights from Montreal Pierre Elliott Trudeau Intl per day. 1 airline has flights to Lambert-St Louis from Montreal Pierre Elliott Trudeau Intl on a regular basis.

  • How long is the flight from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis?

    United Airlines can get you from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis in just under 13h 45m. Your travel time can differ by up to . The distance from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis is about 967 mi.

  • What is the cheapest airline to fly from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis round-trip?

    Our cheapest airline available from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis is Air Canada. Our recent data shows that you can find tickets from as low as $498 on this airline. Air Canada is priced at 21% lower than the current average price of a flight leaving 3 months from now.

  • What are the most reliable airlines from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis?

    No one likes to see their flight delayed. When booking a flight from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis consider choosing United Airlines (64%), Air Canada (59%) or Jazz (50%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis?

    While on average a flight from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis is generally $381, our data shows the cheapest flight currently is $264. When looking at the most popular route, (Montreal Pierre Elliott Trudeau Intl - Lambert-St Louis), you can expect to pay $483 for that flight.

  • Can I find deals for flights from Pierre Elliott Trudeau Intl to St. Louis that include hotel bookings?

    Yes. In addition to deals on Pierre Elliott Trudeau Intl to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Pierre Elliott Trudeau Intl to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Pierre Elliott Trudeau Intl to St. Louis.

  • Can I find deals for business class flights from Pierre Elliott Trudeau Intl to St. Louis?

    Yes. Cheapflights offers flight deals from Pierre Elliott Trudeau Intl to St. Louis by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis?

    Currently, November is the cheapest month in which you can book a flight from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis (average of $542). Flying from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis in January is currently the most expensive (average of $889). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fenton
Swansea
Fairview Heights
Eureka
Maryland Heights
Collinsville
Wentzville
Glencoe
Chesterfield
Farmington

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Top airline flying from Pierre Elliott Trudeau Intl to St. Louis

Discover the top airline that operate flights from Pierre Elliott Trudeau Intl to St. Louis. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated July 26, 2026.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$498Average$575FlexibilityNo cancel feeOn-time67%

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