$136 Cheap Flights from Missoula (MSO) to St. Louis (STL)

View $136 flight on Tue, Jun 10, 2025Opens in a new window

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Find available prices by choosing your travel dates.

Cheap Flights from Missoula to St. Louis (MSO-STL)

Prices were available within the past 7 days and start at $136 for one-way flights and $271 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Mon, Jun 9 - Mon, Jun 16
MSO
Missoula
STL
St. Louis
$271 Roundtrip, found 2 days ago
$271
Roundtrip
found 2 days ago
Select Delta flight, departing Mon, Jun 9 from Missoula to St. Louis, returning Mon, Jun 16, priced at $271 found 2 days ago
Delta
Wed, Jun 11 - Sun, Jun 15
MSO
Missoula
STL
St. Louis
$271 Roundtrip, found 1 day ago
$271
Roundtrip
found 1 day ago
Select Delta flight, departing Wed, Jun 11 from Missoula to St. Louis, returning Sun, Jun 15, priced at $271 found 1 day ago
American Airlines
Thu, Jun 12 - Mon, Jun 16
MSO
Missoula
STL
St. Louis
$272 Roundtrip, found 2 days ago
$272
Roundtrip
found 2 days ago
Select American Airlines flight, departing Thu, Jun 12 from Missoula to St. Louis, returning Mon, Jun 16, priced at $272 found 2 days ago
Delta
Mon, Jun 16 - Thu, Jun 19
MSO
Missoula
STL
St. Louis
$276 Roundtrip, found 6 days ago
$276
Roundtrip
found 6 days ago
Select Delta flight, departing Mon, Jun 16 from Missoula to St. Louis, returning Thu, Jun 19, priced at $276 found 6 days ago
Delta
Tue, Jun 17 - Tue, Jun 24
MSO
Missoula
STL
St. Louis
$280 Roundtrip, found 3 hours ago
$280
Roundtrip
found 3 hours ago
Select Delta flight, departing Tue, Jun 17 from Missoula to St. Louis, returning Tue, Jun 24, priced at $280 found 3 hours ago
American Airlines
Tue, Jun 17 - Tue, Jun 24
MSO
Missoula
STL
St. Louis
$280 Roundtrip, found 3 hours ago
$280
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Tue, Jun 17 from Missoula to St. Louis, returning Tue, Jun 24, priced at $280 found 3 hours ago
Delta
Tue, Jun 17 - Tue, Jun 24
MSO
Missoula
STL
St. Louis
$284 Roundtrip, found 3 hours ago
$284
Roundtrip
found 3 hours ago
Select Delta flight, departing Tue, Jun 17 from Missoula to St. Louis, returning Tue, Jun 24, priced at $284 found 3 hours ago
United
Thu, Jun 5 - Mon, Jun 9
MSO
Missoula
STL
St. Louis
$300 Roundtrip, found 4 days ago
$300
Roundtrip
found 4 days ago
Select United flight, departing Thu, Jun 5 from Missoula to St. Louis, returning Mon, Jun 9, priced at $300 found 4 days ago
Alaska Airlines
Thu, Jun 5 - Mon, Jun 9
MSO
Missoula
STL
St. Louis
$318 Roundtrip, found 4 days ago
$318
Roundtrip
found 4 days ago
Select Alaska Airlines flight, departing Thu, Jun 5 from Missoula to St. Louis, returning Mon, Jun 9, priced at $318 found 4 days ago
Hawaiian Airlines
Sat, May 24 - Sat, May 31
MSO
Missoula
STL
St. Louis
$384 Roundtrip, found 2 days ago
$384
Roundtrip
found 2 days ago
Select Hawaiian Airlines flight, departing Sat, May 24 from Missoula to St. Louis, returning Sat, May 31, priced at $384 found 2 days ago
Flights from Missoula (MSO) to St. Louis (STL)
Origin airport
Missoula Intl.
Destination airport
Lambert-St. Louis Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, United
Roundtrip price
$270
Distance
1320 mi

Missoula to St. Louis Flights

The cheapest times to fly from Missoula to St. Louis

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Missoula to St. Louis are during the month of June. You can find some of the cheapest flights from Missoula to St. Louis with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Missoula to St. Louis

Sunday is one of the best days to book for cheap flights from Missoula to St. Louis: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Missoula to St. Louis

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Missoula to St. Louis in 2025. You can also book with separate airlines for your outbound and return journeys, from $136 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Missoula to St. Louis flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Missoula to St. Louis airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Missoula Intl. Airport (MSO) to Lambert-St. Louis Intl. Airport (STL) cost?
Discover the latest flight deals from MSO to STL by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from MSO to STL?
The cheapest flights from MSO to STL are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from MSO to STL?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that’ll take you from MSO to STL. Sort your results by “Price (lowest to highest)” to snap up a great deal.
How many flights per day from Missoula Intl. Airport (MSO) to Lambert-St. Louis Intl. Airport (STL)?
There are no daily direct flights available from Missoula Intl. Airport (MSO) to Lambert-St. Louis Intl. Airport (STL). But you can opt for flights with layovers. Filter your search on Expedia to include one or more stops, and you’ll be soaring above the clouds in no time at all.
What day of the week has the most flights from MSO to STL?
You’ll generally find Tuesday the quietest day for flights, while Fridays are often the busiest.* However this can change from season to season and during public holidays or peak travel times.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Missoula Intl. Airport (MSO) to Lambert-St. Louis Intl. Airport (STL)?
To touch down at Lambert-St. Louis Intl. Airport (STL) without delays, select a flight that takes off from Missoula Intl. Airport (MSO) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this time.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.
Is it cheaper to buy a plane ticket from Missoula Intl. Airport (MSO) to Lambert-St. Louis Intl. Airport (STL) last-minute?
Booking your plane ticket from MSO to STL shortly before your getaway is typically more expensive. However, if you’re flexible with your travel times and dates, you could bag a cheap last-minute fare.
Is it cheaper to book a MSO to STL flight and hotel package?
You’ll typically save money by securing a MSO to STL flight and hotel package compared to booking separately. In fact, you could save hundreds of dollars by bundling with Expedia. And it’s easy to manage everything in one place. After choosing your ideal accommodations and flights, you can add extras such as car rentals, activities and tours.
Can I cancel or change the date of my flight from Missoula Intl. Airport (MSO) to Lambert-St. Louis Intl. Airport (STL)?
In most instances, you can cancel or reschedule your MSO to STL flight. However, additional fees may apply, especially if you booked over 24 hours ago. Check your itinerary for the airline’s fees and rules on flight changes, or if you want further information, visit our Customer Service portal.

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*Available to One Key members.