$316 Cheap Flights from Casper (CPR) to St. Louis (STL)

View $316 flight on Sat, Aug 30, 2025Opens in a new window

Popular airlines from Casper, WY (CPR-Natrona County Intl.) to St. Louis Lambert Intl. Airport (STL)

Cheap Flights from Casper to St. Louis (CPR-STL)

Prices were available within the past 7 days and start at $316 for one-way flights and $238 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Sat, Nov 1 - Tue, Nov 4
CPR
Casper
STL
St. Louis
$238 Roundtrip, found 1 day ago
$238
Roundtrip
found 1 day ago
Select United flight, departing Sat, Nov 1 from Casper to St. Louis, returning Tue, Nov 4, priced at $238 found 1 day ago
United
Sat, Nov 15 - Tue, Nov 18
CPR
Casper
STL
St. Louis
$244 Roundtrip, found 1 day ago
$244
Roundtrip
found 1 day ago
Select United flight, departing Sat, Nov 15 from Casper to St. Louis, returning Tue, Nov 18, priced at $244 found 1 day ago
United
Sat, Aug 30 - Tue, Sep 2
CPR
Casper
STL
St. Louis
$248 Roundtrip, found 2 days ago
$248
Roundtrip
found 2 days ago
Select United flight, departing Sat, Aug 30 from Casper to St. Louis, returning Tue, Sep 2, priced at $248 found 2 days ago
United
Sat, Nov 1 - Tue, Nov 4
CPR
Casper
STL
St. Louis
$256 Roundtrip, found 1 day ago
$256
Roundtrip
found 1 day ago
Select United flight, departing Sat, Nov 1 from Casper to St. Louis, returning Tue, Nov 4, priced at $256 found 1 day ago
United
Wed, Nov 12 - Wed, Nov 19
CPR
Casper
STL
St. Louis
$258 Roundtrip, found 1 day ago
$258
Roundtrip
found 1 day ago
Select United flight, departing Wed, Nov 12 from Casper to St. Louis, returning Wed, Nov 19, priced at $258 found 1 day ago
United
Sat, Nov 1 - Tue, Nov 4
CPR
Casper
STL
St. Louis
$260 Roundtrip, found 1 day ago
$260
Roundtrip
found 1 day ago
Select United flight, departing Sat, Nov 1 from Casper to St. Louis, returning Tue, Nov 4, priced at $260 found 1 day ago
United
Thu, Sep 4 - Sun, Sep 7
CPR
Casper
STL
St. Louis
$261 Roundtrip, found 1 day ago
$261
Roundtrip
found 1 day ago
Select United flight, departing Thu, Sep 4 from Casper to St. Louis, returning Sun, Sep 7, priced at $261 found 1 day ago
United
Fri, Sep 19 - Mon, Sep 22
CPR
Casper
STL
St. Louis
$263 Roundtrip, found 2 days ago
$263
Roundtrip
found 2 days ago
Select United flight, departing Fri, Sep 19 from Casper to St. Louis, returning Mon, Sep 22, priced at $263 found 2 days ago
United
Wed, Nov 12 - Wed, Nov 19
CPR
Casper
STL
St. Louis
$265 Roundtrip, found 1 day ago
$265
Roundtrip
found 1 day ago
Select United flight, departing Wed, Nov 12 from Casper to St. Louis, returning Wed, Nov 19, priced at $265 found 1 day ago
United
Sat, Nov 1 - Tue, Nov 4
CPR
Casper
STL
St. Louis
$271 Roundtrip, found 1 day ago
$271
Roundtrip
found 1 day ago
Select United flight, departing Sat, Nov 1 from Casper to St. Louis, returning Tue, Nov 4, priced at $271 found 1 day ago

Find the cheapest month to fly from Casper (CPR) to St. Louis (STL)

January is typically the cheapest month to fly

From $238 - $512 per traveler.

Graph displaying average flight prices per month

Flights from Casper (CPR) to St. Louis (STL)
Origin airport
Natrona County Intl.
Destination airport
Lambert-St. Louis Intl.
Airlines serving
United
Roundtrip price
$238
Distance
887 mi

Casper to St. Louis Flights

The cheapest times to fly from Casper 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 Casper to St. Louis are during the month of November. You can find some of the cheapest flights from Casper to St. Louis with Expedia's search tool and vast selection of airlines.

 

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

Sunday is one of the best days to book for cheap flights from Casper 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 Casper 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 Casper to St. Louis in 2025. You can also book with separate airlines for your outbound and return journeys, from $316 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 Casper 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 Casper 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 Natrona County Intl. Airport (CPR) to Lambert-St. Louis Intl. Airport (STL) cost?
Secure a cheap one-way flight from $316 or cheap return flight from $238 from Natrona County Intl. Airport (CPR) to Lambert-St. Louis Intl. Airport (STL) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Natrona County Intl. Airport (CPR) to Lambert-St. Louis Intl. Airport (STL)?
November is the cheapest month to fly from CPR to STL. Planning your trip for the off-season is often the key to finding a great deal.
What is the cheapest airline that flies from Natrona County Intl. Airport (CPR) to Lambert-St. Louis Intl. Airport (STL)?
To find the cheapest airline that'll fly you from CPR to STL, use Expedia's filter tool. Tailor your search based on your travel style, such as preferred carriers and number of stops. You can then sort your results by "Price (lowest to highest)" to list the most affordable options first.
How many flights per day from Natrona County Intl. Airport (CPR) to Lambert-St. Louis Intl. Airport (STL)?
There are no daily direct flights from Natrona County Intl. Airport (CPR) to Lambert-St. Louis Intl. Airport (STL). But you can choose flights with layovers. Filter your search on Expedia to include one or more stops, and you'll be on your way in no time at all.
What day of the week has the most flights from CPR to STL?
Generally you'll find the largest variety of flight choices on a Friday. Tuesdays are often the quietest.* However, this can vary based on the time of year, airline and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Natrona County Intl. Airport (CPR) to Lambert-St. Louis Intl. Airport (STL)?
To land at Lambert-St. Louis Intl. Airport (STL) without delays, select a flight that takes off from Natrona County Intl. Airport (CPR) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this hour.**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 Natrona County Intl. Airport (CPR) to Lambert-St. Louis Intl. Airport (STL) last-minute?
Last-minute fares from CPR to STL are generally more expensive. To lock in the lowest rates, start looking for flights ahead of time. That said, if you can play around with your travel dates, it's possible to score a cheap ticket just before your departure.
Is it cheaper to book a CPR to STL flight and hotel package?
Booking a CPR to STL flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your trip in one place. Pick from our extensive range of accommodations and then add car rentals, flights and activities to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Natrona County Intl. Airport (CPR) to Lambert-St. Louis Intl. Airport (STL)?
If you booked your CPR to STL flight in the last 24 hours, you may be able to cancel or modify it at no cost. Depending on the airline and the type of fare you purchased, additional charges may apply for changes after that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal for more details.

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*Available to One Key members.