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Cheap flights from Montreal to St. Louis from C$ 267

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 19/9. Fares are subject to change and may not be available on all flights or dates of travel.
YMQ — STL
5 Aug — 12 Aug1
1 adult

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 31 July 2025.

Round-trip from

C$ 451

One-way from

C$ 267

Popular in

June

Cheapest in

July

Average price

C$ 396

Good one-way deal

C$ 496 or less
American Airlines
  • American Airlines
  • 13/9-20/9
  • 2 total stops
  • 31h 07m total
  • Montreal to St. Louis
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American Airlines
  • American Airlines
  • 19/9
  • 1 total stop
  • 17h 11m total
  • Montreal to St. Louis
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Highest demand for flights based on searches. 9% potential increase in price (C$ 104 potential increase over avg. RT price).
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Cheapest flight prices on average. 4% potential price decrease (C$ 47 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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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 31 July 2025.

Sat 13/912:31 p.m.YUL - STL
1 stop10h 22mAmerican Airlines
Sat 20/92:01 p.m.STL - YUL
1 stop20h 45mAmerican Airlines
Deal found 30/7C$ 451
Mon 8/96:00 a.m.YUL - STL
1 stop27h 06mDelta
Tue 16/96:40 a.m.STL - YUL
1 stop4h 20mDelta
Deal found 29/7C$ 565
Mon 8/96:10 p.m.YUL - STL
Nonstop2h 47mAir Canada
Tue 16/99:15 a.m.STL - YUL
1 stop6h 05mAir Canada
Deal found 29/7C$ 591
Wed 27/86:15 a.m.YUL - STL
1 stop10h 29mUnited Airlines
Wed 3/97:04 p.m.STL - YUL
1 stop14h 36mUnited Airlines
Deal found 30/7C$ 616
Fri 12/97:00 a.m.YUL - STL
3 stops10h 35mMultiple Airlines
Fri 19/91:00 p.m.STL - YUL
3 stops25h 20mMultiple Airlines
Deal found 29/7C$ 666

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 31 July 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 13/9

12:31 p.m.-9:53 p.m.

1 stop10h 22m

Lambert-St Louis

Sat 20/9

2:01 p.m.-11:46 a.m.

1 stop20h 45m

C$ 451

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 8/9

6:00 a.m.-8:06 a.m.

1 stop27h 06m

Lambert-St Louis

Tue 16/9

6:40 a.m.-12:00 p.m.

1 stop4h 20m

C$ 565

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 8/9

6:10 p.m.-7:57 p.m.

Nonstop2h 47m

Lambert-St Louis

Tue 16/9

9:15 a.m.-4:20 p.m.

1 stop6h 05m

C$ 591

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 27/8

6:15 a.m.-3:44 p.m.

1 stop10h 29m

Lambert-St Louis

Wed 3/9

7:04 p.m.-10:40 a.m.

1 stop14h 36m

C$ 616

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Fri 12/9

7:00 a.m.-4:35 p.m.

3 stops10h 35m

Lambert-St Louis

Fri 19/9

1:00 p.m.-3:20 p.m.

3 stops25h 20m

C$ 666

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Fri 19/9

5:15 p.m.-9:26 a.m.

1 stop17h 11m

C$ 267

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sat 13/9

12:31 p.m.-8:32 p.m.

1 stop9h 01m

C$ 273

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sat 13/9

6:45 a.m.-10:50 a.m.

2 stops29h 05m

C$ 306

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sun 14/9

7:00 a.m.-12:31 p.m.

1 stop6h 31m

C$ 336

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Tue 19/8

6:15 a.m.-2:33 p.m.

1 stop9h 18m

C$ 356

Flights are sorted by cheapest round-trip flights first.

Deals found on 30/7

Showing 1-10 of 12 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 31 July 2025.

Unlike in the evening, when flights are generally more expensive, you can save up to 22% 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 31 July 2025.

The most flights from YMQ to STL are scheduled on a Monday (2 on average). You will have fewer flight options on Friday, which is when the least amount of flights are scheduled (1 on average).

How much does it cost to fly round-trip from Montreal to St. Louis?

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$ 746.

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 31 July 2025.
Read reviews from past customers who have flown Delta,United Airlines, andAmerican Airlines 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.
Delta
8.0
Very good
7,981 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
Delta
8.0
Very good
7,981 reviews
Delta
8.0
Very good
7,981 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
United Airlines
7.4
Good
8,900 reviews
Delta
8.0
Very good
7,981 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
American Airlines
7.2
Good
10,000 reviews
Delta
8.0
Very good
7,981 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
WestJet
7.2
Good
2,978 reviews
Delta
8.0
Very good
7,981 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
Air Canada
7.1
Good
9,851 reviews
Delta
8.0
Very good
7,981 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.

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 1 inbound flight from Montreal per day from 3 airlines. Lambert-St Louis is conveniently located just 20.4 km from St. Louis’s city centre.

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

    Currently priced at C$ 451, American Airlines will fly you from Montreal to St. Louis and back. In addition to American Airlines, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Delta and Air Canada - these airlines can fly you to your destination from C$ 565 and C$ 591, respectively. You may be able to fly from Montreal to St. Louis for 40% less than the average price by searching for these airlines.

  • What are the cheapest airlines to fly from Montreal to St. Louis one-way?

    To fly one-way, consider booking your trip with American Airlines, which is currently one of the cheapest options available, starting at C$ 267. Iberia flights start at C$ 273 while deals on Delta start at C$ 336 one-way.

  • 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: Jazz (67%), Air Canada (63%), United Airlines( 62%).

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

    Looking at all options, your cheapest flight can be booked for C$ 496. While the most popular route (Montreal Pierre Elliott Trudeau Intl - Lambert-St Louis) can be booked for C$ 511 on average our data indicates C$ 496 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 31 July 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 542AverageC$ 746FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
United AirlinesCheapestC$ 593AverageC$ 747FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
WestJetCheapestC$ 742AverageC$ 1,022FlexibilityNo 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.

Can Cheapflights notify me if prices for flights from Montreal to St. Louis become cheaper?

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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