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Cheap flights from Montreal to St. Louis from C$ 268

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 1/10. Fares are subject to change and may not be available on all flights or dates of travel.
YMQ — STL
17 Oct — 24 Oct1
1 adult
1 adult, Economy

Cheap flight deals from Montreal to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Montreal (YMQ) 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 17 September 2025.

Round-trip from

C$ 499

One-way from

C$ 268

Popular in

June

Cheapest in

July

Average price

C$ 770

Good round-trip deal

C$ 1,239 or less

Good one-way deal

C$ 493 or less
American Airlines
  • American Airlines
  • 1/11-8/11
  • 2 total stops
  • 28h 51m total
  • Montreal to St. Louis
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1/10
  • 1/10
  • 3 total stops
  • 27h 45m total
  • Montreal to St. Louis
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Highest demand for flights based on searches. 7% potential increase in price (C$ 85 potential increase over avg. RT price).
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Cheapest flight prices on average. 4% potential price decrease (C$ 45 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from Montreal (YMQ) to Lambert-St Louis.
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Price to beat on a one-way flight from Montreal (YMQ) to Lambert-St Louis.
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Find flight deals from Montreal to St. Louis

Cheapest flights from Montreal to St. Louis
Explore the most affordable flight options available from Montreal to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 17 September 2025.

Sat 1/1112:30 p.m.YUL - STL
1 stop10h 38mAmerican Airlines
Sat 8/117:58 p.m.STL - YUL
1 stop18h 13mAmerican Airlines
Deal found 17/9C$ 499
Thu 6/116:00 a.m.YUL - STL
1 stop10h 46mUnited Airlines
Sat 8/116:43 p.m.STL - YUL
2 stops17h 03mUnited Airlines
Deal found 15/9C$ 619
Wed 5/117:30 p.m.YUL - STL
1 stop13h 43mDelta
Wed 12/119:35 a.m.STL - YUL
1 stop8h 05mDelta
Deal found 14/9C$ 640
Mon 17/113:49 p.m.YUL - STL
1 stop9h 07mAmerican Airlines
Thu 20/116:00 a.m.STL - YUL
1 stop5h 15mAmerican Airlines
Deal found 16/9C$ 693
Tue 18/118:50 a.m.YUL - STL
2 stops7h 39mAir Canada
Sun 30/114:05 p.m.STL - YUL
1 stop6h 17mAir Canada
Deal found 16/9C$ 706
Thu 6/119:10 a.m.YUL - STL
1 stop7h 19mAir Canada
Sat 8/114:05 p.m.STL - YUL
1 stop6h 17mAir Canada
Deal found 15/9C$ 729
Thu 9/107:00 a.m.YUL - STL
1 stop9h 55mDelta
Mon 13/106:00 a.m.STL - YUL
1 stop25h 37mDelta
Deal found 14/9C$ 737
Sat 1/116:00 a.m.YUL - STL
1 stop5h 51mMultiple Airlines
Sun 30/114:05 p.m.STL - YUL
1 stop6h 17mMultiple Airlines
Deal found 15/9C$ 739

Cheapflights 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, Cheapflights users made 629,999 searches. Data last updated 17 September 2025.
Use the filters below to find and compare flights from Montreal to St. Louis that are best for you.

Fly from

Montreal

Fly to

St. Louis

Route

Depart

Return

Price

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sat 1/11

12:30 p.m.-10:08 p.m.

1 stop10h 38m

Lambert-St Louis

Sat 8/11

7:58 p.m.-3:11 p.m.

1 stop18h 13m

C$ 499

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 6/11

3:52 p.m.-11:56 p.m.

1 stop9h 04m

Lambert-St Louis

Sat 8/11

7:58 p.m.-3:11 p.m.

1 stop18h 13m

C$ 499

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 6/11

6:00 a.m.-3:46 p.m.

1 stop10h 46m

Lambert-St Louis

Sat 8/11

6:43 p.m.-12:46 p.m.

2 stops17h 03m

C$ 619

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 5/11

7:30 p.m.-8:13 a.m.

1 stop13h 43m

Lambert-St Louis

Wed 12/11

9:35 a.m.-6:40 p.m.

1 stop8h 05m

C$ 640

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 17/11

3:49 p.m.-11:56 p.m.

1 stop9h 07m

Lambert-St Louis

Thu 20/11

6:00 a.m.-12:15 p.m.

1 stop5h 15m

C$ 693

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Tue 18/11

11:10 a.m.-3:29 p.m.

1 stop5h 19m

Lambert-St Louis

Sun 30/11

4:05 p.m.-11:22 p.m.

1 stop6h 17m

C$ 706

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 6/11

9:10 a.m.-3:29 p.m.

1 stop7h 19m

Lambert-St Louis

Sat 8/11

4:05 p.m.-11:22 p.m.

1 stop6h 17m

C$ 729

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 1/10

6:55 a.m.-9:40 a.m.

3 stops27h 45m

C$ 268

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 27/10

5:24 p.m.-9:28 a.m.

1 stop17h 04m

C$ 292

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 30/10

6:45 a.m.-9:07 a.m.

3 stops27h 22m

C$ 297

Flights are sorted by cheapest round-trip flights first.

Deals found on 15/9

Showing 1-10 of 17 results
1
2

Best time to book a flight from Montreal to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Montreal 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 to St. Louis

What is the cheapest month to book a flight from Montreal to St. Louis?

Currently, January is the cheapest month in which you can book a flight from Montreal to St. Louis (average of C$ 365). Flying from Montreal to St. Louis in September is currently the most expensive (average of C$ 491). 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 YMQ to STL?

Find hourly flight availability from Montreal 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 17 September 2025.

Unlike in the evening, when flights are generally more expensive, you can save up to 27% on flights from Montreal to St. Louis by exploring options for tickets in the morning.

Weekly flight availability from Montreal to St. Louis

Explore weekly flight availability from Montreal to St. Louis. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 17 September 2025.

The most flights from YMQ to STL are scheduled on a Monday (2 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (2 on average).

What’s the top layover airport for flights from Montreal to St. Louis?

Share of one-stop round-trip flights from Montreal to St. Louis chosen by Cheapflights users in the past 12 months, using the same layover each way.

Detroit (DTW) – chosen by Cheapflights users on 45% of one-stop itineraries from Montreal to St. Louis on Cheapflights.

What’s the cheapest layover airport for flights from Montreal to St. Louis?

Average round-trip fare for 1-stop flights from Montreal to St. Louis, chosen by Cheapflights users in the past 12 months, with the same layover each way.

Toronto (YYZ) is the most affordable 1-stop option, with an average round-trip price of C$ 742.

What’s the fastest layover option from Montreal to St. Louis?

Shortest average travel time for 1-stop one-way flights from Montreal to St. Louis, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.

Flights via Detroit (DTW) have the shortest average one-way travel time for 1-stop routes: 5h 03m.

Which airport typically offers the quickest layover for flights from Montreal to St. Louis?

Average layover duration for 1-stop one-way flights from Montreal to St. Louis, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Detroit (DTW) offer the fastest connection on this route, with an average layover time of 1h 09m.

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 17 September 2025.
Read reviews from past customers who have flown Air Canada from Montreal to St. Louis. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Air Canada
7.1
Good
10,000 reviews
Check prices

Entertainment

6.8

Overall

7.1

Boarding

7.3

Comfort

7.1

Crew

7.8

Food

6.3

Reviews

1 / 20
4.0
Okay

Anonymous,Oct 2024

YUL - YYZ

Was able to check the smaller carryon suitcase in Montreal but it was tagged incorrectly and we still have not received it or heard where it is.
Air Canada
7.1
Good
10,000 reviews
Air Canada
7.1
Good
10,000 reviews
Check prices

Entertainment

6.8

Overall

7.1

Boarding

7.3

Comfort

7.1

Crew

7.8

Food

6.3

Reviews

1 / 20
4.0
Okay

Anonymous,Oct 2024

YUL - YYZ

Was able to check the smaller carryon suitcase in Montreal but it was tagged incorrectly and we still have not received it or heard where it is.

Related info for your journey

Find useful and relevant information for your journey from Montreal 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?

    Most people fly into Lambert-St Louis (STL) if they book a flight to St. Louis from Montreal. On average, Lambert-St Louis has 2 inbound flights from Montreal per day from 3 airlines. Lambert-St Louis is conveniently located just 20.4 km from St. Louis’s city centre.

  • How long is the flight from Montreal to St. Louis?

    Airlines like American Airlines, United Airlines, and Delta fly from Montreal to St. Louis in about 10h 38m. The time it takes to get you to your destination can typically vary by up to 3h 05m. The distance from Montreal to St. Louis is about 1556 km. This flight may include one or multiple stops.

  • What are the cheapest airlines flying from Montreal to St. Louis round-trip?

    Currently priced at C$ 539, Air Canada will fly you from Montreal to St. Louis and back. In addition to Air Canada, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from United Airlines and WestJet - these airlines can fly you to your destination from C$ 590 and C$ 737, respectively. You may be able to fly from Montreal to St. Louis for 29% less than the average price by searching for these airlines.

  • What are the most reliable airlines from Montreal to St. Louis?

    Before booking your flight to St. Louis from Montreal, check out the most reliable airlines to get you to your destination on time: Sun Country Air (100%), Air Canada (70%), Jazz( 70%).

  • What are the cheapest flights from Montreal to St. Louis?

    Looking at all options, your cheapest flight can be booked for C$ 493. While the most popular route (Montreal Pierre Elliott Trudeau Intl - Lambert-St Louis) can be booked for C$ 592 on average, our data indicates C$ 955 when flying from Montreal to St. Louis.

  • Can I find deals for flights from Montreal to St. Louis that include hotel bookings?

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

  • How can I find direct flights from Montreal to St. Louis?

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

  • Can I find deals for business class flights from Montreal to St. Louis?

    Yes. Cheapflights offers flight deals from Montreal 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 to St. Louis?

    Currently, January is the cheapest month in which you can book a flight from Montreal to St. Louis (average of C$ 365). Flying from Montreal to St. Louis in September is currently the most expensive (average of C$ 491). 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

Travelling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Chesterfield
St. Peters

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Top 3 airlines flying from Montreal to St. Louis

Discover the top 3 airlines that operate flights from Montreal 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 629,999 searches. Data last updated 17 September 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 539AverageC$ 741FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
United AirlinesCheapestC$ 590AverageC$ 628FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
WestJetCheapestC$ 737AverageC$ 1,048FlexibilityNo cancel feeOn-time60%
Search WestJet flights

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How does Cheapflights help users find flights from Montreal to St. Louis?

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Can Cheapflights find flights from Montreal to St. Louis with no change fees?

Certainly. Search results for flights to St. Louis from Montreal shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

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Not ready to book yet? You can track prices for flights from Montreal to St. Louis on Cheapflights with our Price Alert feature and get notified when better prices are available.

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