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Cheap flights from Montreal to St. Louis from C$ 314

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 15/12. Fares are subject to change and may not be available on all flights or dates of travel.
YMQ — STL
4 Dec — 11 Dec1
1 adult
1 adult, Economy, 0 bags

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Enter your travel dates to find the best prices.

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 4 November 2025.

Sun 16/114:35 p.m.YUL - STL
1 stop21h 42mMultiple Airlines
Wed 3/123:30 p.m.STL - YUL
2 stops23h 55mMultiple Airlines
Deal found 1/11C$ 577
Sat 15/113:55 p.m.YUL - STL
2 stops22h 22mMultiple Airlines
Thu 27/1110:53 a.m.STL - YUL
1 stop27h 17mMultiple Airlines
Deal found 2/11C$ 585
Fri 5/128:00 a.m.YUL - STL
2 stops15h 33mMultiple Airlines
Sun 7/129:54 a.m.STL - YUL
1 stop13h 36mMultiple Airlines
Deal found 3/11C$ 615
Thu 25/127:08 a.m.YUL - STL
1 stop13h 22mAmerican Airlines
Thu 1/15:30 a.m.STL - YUL
1 stop5h 50mAmerican Airlines
Deal found 3/11C$ 727
Thu 25/127:00 a.m.YUL - STL
2 stops13h 18mUnited Airlines
Thu 1/19:55 a.m.STL - YUL
1 stop7h 45mUnited Airlines
Deal found 3/11C$ 755
Fri 5/123:00 p.m.YUL - STL
2 stops8h 45mUnited Airlines
Sun 7/126:30 a.m.STL - YUL
2 stops7h 46mUnited Airlines
Deal found 3/11C$ 769
Fri 26/1210:10 a.m.YUL - STL
1 stop6h 19mAir Canada
Fri 2/14:05 p.m.STL - YUL
1 stop6h 18mAir Canada
Deal found 3/11C$ 779
Sun 16/116:26 p.m.YUL - STL
1 stop6h 18mDelta
Wed 3/1212:49 p.m.STL - YUL
1 stop9h 58mDelta
Deal found 1/11C$ 788
Fri 5/1211:10 a.m.YUL - STL
1 stop5h 19mAir Canada
Sun 7/124:05 p.m.STL - YUL
1 stop6h 17mAir Canada
Deal found 3/11C$ 789
Mon 24/1112:59 p.m.YUL - STL
1 stop6h 18mAmerican Airlines
Wed 26/117:11 a.m.STL - YUL
1 stop14h 29mAmerican Airlines
Deal found 3/11C$ 797
Sat 8/114:35 p.m.YUL - STL
1 stop24h 43mMultiple Airlines
Sat 15/117:45 p.m.STL - YUL
2 stops27h 45mMultiple Airlines
Deal found 3/11C$ 834

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 4 November 2025.

Round-trip from

C$ 522

One-way from

C$ 314

Popular in

June

Cheapest in

July

Average price

C$ 917

Good one-way deal

C$ 504 or less
American Airlines
  • American Airlines
  • 7/4-8/4
  • 2 total stops
  • 33h 19m total
  • Montreal to St. Louis
Search Deals
15/12
  • 15/12
  • 3 total stops
  • 30h 08m total
  • Montreal to St. Louis
Search Deals
Highest demand for flights based on searches. 4% potential increase in price (C$ 49 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (C$ 44 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2025
Search Deals
Price to beat on a one-way flight from Montreal (YMQ) to Lambert-St Louis.
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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 4 November 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

Tue 7/4

12:30 p.m.-9:48 p.m.

1 stop10h 18m

Lambert-St Louis

Wed 8/4

11:14 a.m.-11:15 a.m.

1 stop23h 01m

C$ 522

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sun 16/11

4:35 p.m.-1:17 p.m.

1 stop21h 42m

Lambert-St Louis

Wed 3/12

3:30 p.m.-4:25 p.m.

2 stops23h 55m

C$ 577

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Fri 5/12

8:00 a.m.-10:33 p.m.

2 stops15h 33m

Lambert-St Louis

Sun 7/12

9:54 a.m.-12:30 a.m.

1 stop13h 36m

C$ 615

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 25/12

7:08 a.m.-7:30 p.m.

1 stop13h 22m

Lambert-St Louis

Thu 1/1

5:30 a.m.-12:20 p.m.

1 stop5h 50m

C$ 727

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 25/12

7:00 a.m.-7:18 p.m.

2 stops13h 18m

Lambert-St Louis

Thu 1/1

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

1 stop7h 45m

C$ 755

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Fri 5/12

3:00 p.m.-10:45 p.m.

2 stops8h 45m

Lambert-St Louis

Sun 7/12

6:30 a.m.-3:16 p.m.

2 stops7h 46m

C$ 769

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 26/3

12:45 p.m.-6:04 p.m.

1 stop6h 19m

Lambert-St Louis

Sat 28/3

3:50 p.m.-11:39 p.m.

1 stop6h 49m

C$ 775

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Sat 21/2

2:40 p.m.-11:25 p.m.

1 stop9h 45m

Lambert-St Louis

Sat 7/3

6:10 a.m.-1:42 p.m.

1 stop6h 32m

C$ 778

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Fri 19/12

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

1 stop5h 19m

Lambert-St Louis

Sat 3/1

4:05 p.m.-10:22 p.m.

1 stop5h 17m

C$ 779

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 15/12

5:25 p.m.-10:33 p.m.

3 stops30h 08m

C$ 314

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/11

Showing 1-10 of 16 results
1
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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, March is the cheapest month in which you can book a flight from Montreal to St. Louis (average of C$ 550). Flying from Montreal to St. Louis in August is currently the most expensive (average of C$ 817). 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 4 November 2025.

Unlike in the evening, when flights are generally more expensive, you can save up to 26% on flights from Montreal to St. Louis by exploring options for tickets in the morning.

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.

Toronto (YYZ) – chosen by Cheapflights users on 43% 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.

Newark (EWR) is the most affordable 1-stop option, with an average round-trip price of C$ 745.

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: 4h 55m.

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 02m.

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 4 November 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
10,403 reviews
Check prices

Entertainment

6.8

Boarding

7.3

Crew

7.8

Food

6.3

Comfort

7.1

Overall

7.1

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
10,403 reviews
Air Canada
7.1
Good
10,403 reviews
Check prices

Entertainment

6.8

Boarding

7.3

Crew

7.8

Food

6.3

Comfort

7.1

Overall

7.1

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 0 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 fly from Montreal to St. Louis in about 10h 18m. The time it takes to get you to your destination can typically vary by up to . The distance from Montreal to St. Louis is about 1556 km.

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

    Currently priced at C$ 550, 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$ 602 and C$ 752, respectively. You may be able to fly from Montreal to St. Louis for 31% 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$ 504. While the most popular route (Montreal Pierre Elliott Trudeau Intl - Lambert-St Louis) can be booked for C$ 615 on average, our data indicates C$ 504 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, March is the cheapest month in which you can book a flight from Montreal to St. Louis (average of C$ 550). Flying from Montreal to St. Louis in August is currently the most expensive (average of C$ 817). 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 4 November 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 550AverageC$ 756FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
United AirlinesCheapestC$ 602AverageC$ 641FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
WestJetCheapestC$ 752AverageC$ 1,037FlexibilityNo cancel feeOn-time60%
Search WestJet flights

Fly with Cheapflights

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

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It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Montreal to St. Louis.

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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