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Cheap flights from Montreal to St. Louis from C$ 322

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 10/9. Fares are subject to change and may not be available on all flights or dates of travel.
YMQ — STL
1 Sep — 8 Sep1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Montreal to St. Louis

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 2 August 2026.

Thu 15/1012:30 p.m.
YUL
-
STL
1 stop9h 38m
American Airlines
Mon 19/105:27 p.m.
STL
-
YUL
1 stop17h 17m
American Airlines
Deal found 30/7C$ 609
Wed 23/912:31 p.m.
YUL
-
STL
1 stop12h 56m
American Airlines
Wed 30/95:00 a.m.
STL
-
YUL
1 stop10h 53m
American Airlines
Deal found 29/7C$ 637
Wed 26/85:34 p.m.
YUL
-
STL
1 stop15h 50m
American Airlines
Wed 2/92:55 p.m.
STL
-
YUL
1 stop17h 51m
American Airlines
Deal found 29/7C$ 670
Wed 23/94:55 p.m.
YUL
-
STL
Nonstop2h 46m
Air Canada
Wed 30/912:10 p.m.
STL
-
YUL
Nonstop2h 31m
Air Canada
Deal found 31/7C$ 701
Wed 23/98:30 a.m.
YUL
-
STL
2 stops14h 08m
United Airlines
Wed 30/98:00 a.m.
STL
-
YUL
1 stop9h 55m
United Airlines
Deal found 28/7C$ 705
Thu 15/104:55 p.m.
YUL
-
STL
Nonstop2h 46m
Air Canada
Mon 19/1012:10 p.m.
STL
-
YUL
Nonstop2h 31m
Air Canada
Deal found 29/7C$ 710

Find 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 2 August 2026.

Round-trip from

C$ 609

One-way from

C$ 322

Popular in

September

Cheapest in

June

Average price

C$ 792
American Airlines
  • American Airlines
  • 15/10-19/10
  • 2 total stops
  • 26h 55m total
  • Montreal to St. Louis
Search Deals
American Airlines
  • American Airlines
  • 10/9
  • 1 total stop
  • 17h 44m total
  • Montreal to St. Louis
Search Deals
Highest demand for flights based on searches. 15% potential increase in price (C$ 224 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (C$ 53 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in August 2026
Search Deals

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 2 August 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 - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 13/1

12:59 p.m.-11:58 p.m.

2 stops11h 59m

Lambert-St Louis

Wed 20/1

5:00 a.m.-3:07 p.m.

1 stop9h 07m

C$ 694

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 23/9

8:30 a.m.-9:38 p.m.

2 stops14h 08m

Lambert-St Louis

Wed 30/9

8:00 a.m.-6:55 p.m.

1 stop9h 55m

C$ 705
Quickest round-trip

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 15/10

4:55 p.m.-6:41 p.m.

Nonstop2h 46m

Lambert-St Louis

Mon 19/10

12:10 p.m.-3:41 p.m.

Nonstop2h 31m

C$ 710

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Tue 27/10

4:45 p.m.-9:40 p.m.

1 stop5h 55m

Lambert-St Louis

Sat 31/10

3:15 p.m.-9:17 p.m.

1 stop5h 02m

C$ 723

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 27/8

1:15 p.m.-10:00 p.m.

1 stop9h 45m

Lambert-St Louis

Mon 31/8

12:59 p.m.-10:40 a.m.

1 stop20h 41m

C$ 733

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 15/10

8:00 p.m.-9:09 a.m.

2 stops14h 09m

Lambert-St Louis

Mon 19/10

5:35 p.m.-11:59 p.m.

1 stop5h 24m

C$ 761

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 13/1

9:28 a.m.-8:51 p.m.

1 stop12h 23m

Lambert-St Louis

Wed 20/1

7:00 a.m.-6:50 p.m.

1 stop10h 50m

C$ 771

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Wed 18/11

6:45 a.m.-6:13 p.m.

2 stops12h 28m

Lambert-St Louis

Sun 22/11

5:37 p.m.-5:29 p.m.

1 stop22h 52m

C$ 772
Cheapest one-way

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 10/9

5:34 p.m.-10:18 a.m.

1 stop17h 44m

C$ 322

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Mon 31/8

6:30 a.m.-5:22 p.m.

3 stops11h 52m

C$ 325

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/8

Showing 1-10 of 18 resultsSorted by cheapest first
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, February is the cheapest month in which you can book a flight from Montreal to St. Louis (average of C$ 768). Flying from Montreal to St. Louis in December is currently the most expensive (average of C$ 1,125). 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 2 August 2026.

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

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 2 August 2026.

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).

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

Airfare is below average for this route at the moment.
Montreal to St. Louis flights typically cost between C$ 657 and C$ 1,044 in October.
The cheapest round-trip price found within the last 5 days was C$ 609 on American Airlines (15 Oct-19 Oct).

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 73% 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$ 744.

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 46m.

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 0h 43m.

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 2 August 2026.
Read reviews from past customers who have flown United Airlines and 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.
United Airlines
7.4
Good
10,062 reviews
Check prices

Boarding

7.7

Entertainment

7.1

Food

6.7

Crew

8.1

Comfort

7.3

Overall

7.4

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats
United Airlines
7.4
Good
10,062 reviews
United Airlines
7.4
Good
10,062 reviews
Check prices

Boarding

7.7

Entertainment

7.1

Food

6.7

Crew

8.1

Comfort

7.3

Overall

7.4

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats
Air Canada
7.1
Good
11,418 reviews
United Airlines
7.4
Good
10,062 reviews
Check prices

Boarding

7.7

Entertainment

7.1

Food

6.7

Crew

8.1

Comfort

7.3

Overall

7.4

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats

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 1 airline. 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 Air Canada fly from Montreal to St. Louis in about 2h 46m. The time it takes to get you to your destination can typically vary by up to 11h 22m. The distance from Montreal to St. Louis is about 1556 km. This flight may include one or multiple stops.

  • What is the cheapest airline to fly from Montreal to St. Louis round-trip?

    Currently priced at C$ 565, 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. You may be able to fly from Montreal to St. Louis for 33% less than the average price by searching for this airline.

  • 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 (64%), United Airlines( 45%).

  • 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, February is the cheapest month in which you can book a flight from Montreal to St. Louis (average of C$ 768). Flying from Montreal to St. Louis in December is currently the most expensive (average of C$ 1,125). 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
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Top airline flying from Montreal to St. Louis

Discover the top airline 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 2 August 2026.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 565AverageC$ 771FlexibilityNo cancel feeOn-time67%
Search Air Canada flights

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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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