£194 Cheap Flights from St. Louis (STL) to Denver (DEN)

View £194 flight on Tue, 9 Jun 2026Opens in a new window

Flight 1

Popular airlines from Lambert-St. Louis International Airport (STL) to Denver International Airport (DEN)

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Cheap Flights from St. Louis (STL) to Denver (DEN)

Prices were available within the past 7 days and start at £194 for one-way flights and £508 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Alaska Airlines
Tue, 19 May - Wed, 20 May
STL
St. Louis
DEN
Denver
£508 Return, found 3 days ago
£508
Return
found 3 days ago
Select Alaska Airlines flight, departing Tue, 19 May from St. Louis to Denver, returning Wed, 20 May, priced at £508 found 3 days ago
Alaska Airlines
Tue, 19 May - Wed, 20 May
STL
St. Louis
DEN
Denver
£513 Return, found 3 days ago
£513
Return
found 3 days ago
Select Alaska Airlines flight, departing Tue, 19 May from St. Louis to Denver, returning Wed, 20 May, priced at £513 found 3 days ago
Alaska Airlines
Tue, 19 May - Wed, 20 May
STL
St. Louis
DEN
Denver
£515 Return, found 3 days ago
£515
Return
found 3 days ago
Select Alaska Airlines flight, departing Tue, 19 May from St. Louis to Denver, returning Wed, 20 May, priced at £515 found 3 days ago
Alaska Airlines
Mon, 10 Aug - Mon, 17 Aug
STL
St. Louis
DEN
Denver
£516 Return, found 1 day ago
£516
Return
found 1 day ago
Select Alaska Airlines flight, departing Mon, 10 Aug from St. Louis to Denver, returning Mon, 17 Aug, priced at £516 found 1 day ago
Alaska Airlines
Mon, 10 Aug - Mon, 17 Aug
STL
St. Louis
DEN
Denver
£535 Return, found 1 day ago
£535
Return
found 1 day ago
Select Alaska Airlines flight, departing Mon, 10 Aug from St. Louis to Denver, returning Mon, 17 Aug, priced at £535 found 1 day ago
Alaska Airlines
Tue, 19 May - Wed, 20 May
STL
St. Louis
DEN
Denver
£548 Return, found 3 days ago
£548
Return
found 3 days ago
Select Alaska Airlines flight, departing Tue, 19 May from St. Louis to Denver, returning Wed, 20 May, priced at £548 found 3 days ago
Alaska Airlines
Thu, 28 May - Mon, 1 Jun
STL
St. Louis
DEN
Denver
£567 Return, found 3 days ago
£567
Return
found 3 days ago
Select Alaska Airlines flight, departing Thu, 28 May from St. Louis to Denver, returning Mon, 1 Jun, priced at £567 found 3 days ago
Alaska Airlines
Thu, 28 May - Mon, 1 Jun
STL
St. Louis
DEN
Denver
£578 Return, found 3 days ago
£578
Return
found 3 days ago
Select Alaska Airlines flight, departing Thu, 28 May from St. Louis to Denver, returning Mon, 1 Jun, priced at £578 found 3 days ago
Alaska Airlines
Thu, 28 May - Mon, 1 Jun
STL
St. Louis
DEN
Denver
£593 Return, found 3 days ago
£593
Return
found 3 days ago
Select Alaska Airlines flight, departing Thu, 28 May from St. Louis to Denver, returning Mon, 1 Jun, priced at £593 found 3 days ago
Alaska Airlines
Thu, 18 Jun - Sun, 21 Jun
STL
St. Louis
DEN
Denver
£816 Return, found 10 hours ago
£816
Return
found 10 hours ago
Select Alaska Airlines flight, departing Thu, 18 Jun from St. Louis to Denver, returning Sun, 21 Jun, priced at £816 found 10 hours ago

Frequently asked questions

What is the cheapest month to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
September is typically the cheapest month to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.), with average return fares of approximately £204. This is about 12% lower than the average price throughout the year. September often sees lower prices as the summer travel rush ends and before the holiday season begins, leading to reduced demand. Other cheap months to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) include January and August.
Which airlines fly direct from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
Enter STL to DEN and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
How do I find cheap flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
To find a cheap flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best airline to fly with from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
The best airline to fly with from St. Louis, MO (STL-Lambert-St. Louis Intl.) (STL) to Denver, CO (DEN-Denver Intl.) (DEN) will differ from traveller to traveller. If you like to fly early, UA offers early morning flights. If price is the most important factor, F9 typically offers the lowest fares. WN offers the most daily flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) (STL) to Denver, CO (DEN-Denver Intl.) (DEN), which is brilliant if flexibility is what you value most. The best carrier for this journey could also be the one you have a loyalty membership with, as flying with that airline or another airline within the same alliance could help you collect points or enjoy lounge access.
What is the best time to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
The best time to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) (STL) to Denver, CO (DEN-Denver Intl.) (DEN) is September. Based on booking data from the past year, September offers a great balance, being one of the cheapest months with an average return flight price of around £204, and it's also a popular time to travel, meaning you'll have plenty of flight options to choose from. If you're looking for good value and a wide selection of flights, September is an excellent choice.
How many flights per day from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
When flying from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.), you'll find approximately 13 nonstop flights per day. For even more choice, look at flights that include layovers, as there are around 149 connecting flights per day. Some common connection points include O'Hare Intl. (ORD), Seattle - Tacoma Intl. (SEA), and Dallas-Fort Worth Intl. (DFW).
What is the earliest flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
The earliest flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) typically departs at approximately 5:00 AM local time. This service is operated by American Airlines and is seasonal, active in January, November, and December. An early departure like this can help you maximise your time at your destination. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What day of the week has the most flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
You'll typically find the most flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) on a Friday, with around 101 flights available. This gives you plenty of options for your travel plans. Major airlines on this route include Southwest Airlines, United Airlines, and American Airlines. Fridays offer notably more flight options compared to other days of the week.
What are the most popular departure times for flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
The most popular departure times for flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) are in the early morning, from 6am to 9am. Approximately 26% of passengers prefer this time window. Many major carriers, including Southwest Airlines and American Airlines, offer flights during this window. These times work well because you can get an early start to your day in Denver.
How long does it take to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
Direct flights from STL to DEN usually take about 2 hours 30 minutes, traveling roughly 768 miles. If you opt for a connecting flight, expect to add around 5 hours 20 minutes to your journey. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
Select the "Business class" and "First class" filters when looking for STL to DEN flights on Expedia. This is the easiest way to compare prices, routes and flight times for your trip.
How do I earn miles on a St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) flight with Expedia?
It's easy to earn miles on a St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia. *Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for Denver from Lambert-St. Louis Intl. (STL)?
From Lambert-St. Louis Intl. (STL), you can fly directly into Denver Intl. (DEN) to reach Denver. Some flights may connect through major hubs like Seattle - Tacoma Intl. (SEA), Love Field (DAL), Midway Intl. (MDW) before reaching Denver. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) at the last minute?
Typically, booking a last minute flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) flight and hotel package?
Securing a St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.)?
If you booked your St. Louis, MO (STL-Lambert-St. Louis Intl.) to Denver, CO (DEN-Denver Intl.) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
Lambert-St. Louis Intl.
Destination airport
Denver Intl.
Airlines serving
Alaska Airlines
Return price
£508
Distance
1228 km
Average flight time
1 hour 24 mins

Book with confidence

Compare flights from St. Louis to Denver easily and book with confidence

For travelling on business or for pleasure, Expedia makes it easy to book your flights from St. Louis to Denver. Operating between them flights per day, 20 airlines cover the route. And fly direct, getting you to Denver Intl. in just hours. If you have a preferred carrier, use our advanced search tool to find the right flight from Lambert-St. Louis Intl. to Denver Intl..  

To make things even better, in the advanced search, you can also choose to fly economy, premium economy, business or first class, select your maximum number of stops, and pick your preferred departure and arrival time. You can also opt for refundable and direct flights. 

Grab a great deal on your flight from Lambert-St. Louis Intl. (STL) to Denver Intl. (DEN)

The easiest way to view the best deals on flights from St. Louis to Denver today is to enter your travel dates and hit search. From here, you can sort your results by price to see the cheapest flights first. Right now, return flights from Lambert-St. Louis Intl. to Denver Intl. start at just £508 and range up to £816.  

To find an even better deal, try  

  • being flexible on your dates – midweek flights can be cheaper
  • looking for other airports near St. Louis and Denver
  • booking your flight during May, the cheapest month on this route
  • varying your flight times – early morning and late at night are sometimes cheaper 

Why you should book your St. Louis to Denver flight with Expedia!

We cater for all flight types, cabin classes and airlines. So whether you’re booking flights from Lambert-St. Louis Intl. to Denver Intl. for a budget break or a business trip with a bit of pleasure thrown in, we make it easy to secure the seat that’s right for you.  

Thanks to our supersized inventory that offers great choice all in one place, you know you’ll get a great deal with Expedia. Especially if you bundle your flight together with your hotel, you will unlock amazing savings. For added peace of mind, you can choose flexible bookings or filter to find refundable options, so you won’t pay a fee to change your flight.  

Compare flights from St. Louis to Denver easily and book with confidence

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