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

View AU$141 flight on Sat, 26 Sept 2026Opens in a new window

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

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

Prices were available within the past 7 days for one-way flights and round trip tickets for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Wed, 9 Sept - Thu, 17 Sept
DEN
Denver
STL
St. Louis
AU$448 Return, found 3 days ago
AU$448
Return
found 3 days ago
Select Delta flight, departing Wed, 9 Sept from Denver to St. Louis, returning Thu, 17 Sept, priced at AU$448 found 3 days ago
American Airlines
Wed, 9 Sept - Thu, 17 Sept
DEN
Denver
STL
St. Louis
AU$453 Return, found 3 days ago
AU$453
Return
found 3 days ago
Select American Airlines flight, departing Wed, 9 Sept from Denver to St. Louis, returning Thu, 17 Sept, priced at AU$453 found 3 days ago
American Airlines
Sun, 20 Sept - Mon, 28 Sept
DEN
Denver
STL
St. Louis
AU$455 Return, found 3 days ago
AU$455
Return
found 3 days ago
Select American Airlines flight, departing Sun, 20 Sept from Denver to St. Louis, returning Mon, 28 Sept, priced at AU$455 found 3 days ago
United
Wed, 9 Sept - Thu, 17 Sept
DEN
Denver
STL
St. Louis
AU$476 Return, found 3 days ago
AU$476
Return
found 3 days ago
Select United flight, departing Wed, 9 Sept from Denver to St. Louis, returning Thu, 17 Sept, priced at AU$476 found 3 days ago
Delta
Wed, 9 Sept - Thu, 17 Sept
DEN
Denver
STL
St. Louis
AU$477 Return, found 3 days ago
AU$477
Return
found 3 days ago
Select Delta flight, departing Wed, 9 Sept from Denver to St. Louis, returning Thu, 17 Sept, priced at AU$477 found 3 days ago
United
Wed, 9 Sept - Thu, 17 Sept
DEN
Denver
STL
St. Louis
AU$490 Return, found 3 days ago
AU$490
Return
found 3 days ago
Select United flight, departing Wed, 9 Sept from Denver to St. Louis, returning Thu, 17 Sept, priced at AU$490 found 3 days ago
Delta
Wed, 9 Sept - Thu, 17 Sept
DEN
Denver
STL
St. Louis
AU$496 Return, found 3 days ago
AU$496
Return
found 3 days ago
Select Delta flight, departing Wed, 9 Sept from Denver to St. Louis, returning Thu, 17 Sept, priced at AU$496 found 3 days ago
Delta
Wed, 9 Sept - Thu, 17 Sept
DEN
Denver
STL
St. Louis
AU$498 Return, found 3 days ago
AU$498
Return
found 3 days ago
Select Delta flight, departing Wed, 9 Sept from Denver to St. Louis, returning Thu, 17 Sept, priced at AU$498 found 3 days ago
American Airlines
Sun, 20 Sept - Mon, 28 Sept
DEN
Denver
STL
St. Louis
AU$502 Return, found 3 days ago
AU$502
Return
found 3 days ago
Select American Airlines flight, departing Sun, 20 Sept from Denver to St. Louis, returning Mon, 28 Sept, priced at AU$502 found 3 days ago
Alaska Airlines
Sun, 20 Sept - Mon, 28 Sept
DEN
Denver
STL
St. Louis
AU$832 Return, found 3 days ago
AU$832
Return
found 3 days ago
Select Alaska Airlines flight, departing Sun, 20 Sept from Denver to St. Louis, returning Mon, 28 Sept, priced at AU$832 found 3 days ago

Frequently asked questions

How much does a flight from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) cost?
You can find one-way and return flights from DEN to STL with Expedia. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see our cheapest fares first, and use the Price Tracking tool to receive alerts when DEN to STL ticket fares go up or down.
What is the cheapest month to fly from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
If you're looking for the most budget-friendly time to fly from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.), September is typically the cheapest month. You can expect average return flight prices around AU$410. September often sees lower prices as the summer travel rush ends and before the holiday season begins, leading to less demand. Other great months to find deals on this route include August and October.
Which airlines fly direct from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
You have 3 airlines offering direct flights from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.). Here are the carriers:
  • Southwest Airlines operates 49 direct flights from DEN to STL every week.
  • United operates 32 direct flights from DEN to STL every week.
  • Frontier Airlines operates 7 direct flights from DEN to STL every week.
How do I find cheap flights from Denver, CO (DEN) to St. Louis, MO (STL)?
To find a cheap flight from Denver, CO (DEN) to St. Louis, MO (STL), 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 Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The best airline to fly with from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) will differ from traveler to traveler. If you like to fly early, Southwest Airlines offers early morning flights. If price is the most important factor, Frontier Airlines typically offers the lowest fares. Southwest Airlines offers the most daily flights from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.), which is great 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 Denver, CO (DEN) to St. Louis, MO (STL)?
The best time to fly is usually mid-week (Tuesday or Wednesday) and during early morning hours as flights tend to be cheaper, less crowded, and generally more on-time. Avoid major holidays and peak vacation seasons for smoother travel. Combining off-peak days and hours often gives the best combination of cost, comfort, and convenience.
How many flights per day from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
You'll find around 13 nonstop flights per day from Denver International (DEN) to Lambert-St. Louis International (STL). For even more choices, look at flights that include layovers, as there are approximately 172 connecting flights per day. Some common connection points include Seattle - Tacoma International (SEA), O'Hare International (ORD), and Portland International (PDX).
What is the earliest flight from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The earliest flight from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) typically departs around 12:00 AM local time, operated by Frontier Airlines. This is a seasonal service, active in August, September, and October. An early departure like this can help you make the most of 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 Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
You'll typically find the most flights from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) on a Friday, with around 117 flights available. This gives you plenty of options for your travel plans. Major airlines on this route include Southwest Airlines, Delta, and American Airlines. Friday offers notably more flight options compared to other days of the week, making it a good day to consider if you need flexibility.
What are the most popular departure times for flights from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The most popular departure times for flights from Denver International Airport (DEN) to Lambert-St. Louis International Airport (STL) are in the early morning, from 6am to 9am. Many major carriers, including Southwest Airlines, American Airlines and Frontier Airlines, offer flights during this window. Many travellers prefer these times because they allow for an early start to their day in St. Louis.
How long does it take to fly from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
A direct flight from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) typically takes around 2 hours, covering a distance of approximately 1,236 kilometres. If you opt for a flight with one stop, your travel time will be longer, usually around 5 hours 48 minutes. Flights with two or more stops generally take about 10 hours. Keep in mind that actual flight times can vary due to factors like wind patterns and air traffic, so it's always a good idea to allow for some extra time when planning your trip.
Can you fly business or first class from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Yes, you can fly business class or first class between DEN and STL. You can fly business class with Frontier Airlines and Delta.First class cabins are available on Alaska Airlines, Delta, United, and American Airlines.
How do I earn miles on a Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight with Expedia?
It's easy to earn miles on a Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis 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 St. Louis, MO (STL) from Denver, CO (DEN)?
If you're planning to travel to St. Louis from Denver Intl. (DEN), you can fly directly into Lambert-St. Louis Intl. (STL) which offers international flights and connections. Some flights may connect through major hubs like Portland Intl. (PDX), Love Field (DAL), or Seattle - Tacoma Intl. (SEA) before reaching St. Louis. 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 Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) at the last minute?
Typically, booking a last minute flight from Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis 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 Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight and hotel package?
Securing a Denver, CO (DEN-Denver Intl.) to St. Louis, MO (STL-Lambert-St. Louis 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 Denver, CO (DEN) to St. Louis, MO (STL)?
If you booked your Denver, CO (DEN) to St. Louis, MO (STL) 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
Denver Intl.
Destination airport
Lambert-St. Louis Intl.
Roundtrip price
AU$448
Distance
1228 km
Average flight time
3 hours 2 mins

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Your quick guide to flights from Denver to St. Louis

Pick up great flights from Denver to St. Louis

With Expedia, you have your pick of flights a day with 20 airlines covering flights from Denver to St. Louis. Whether you’re on a business trip, a family holiday or a luxury break, just enter your travel dates, hit search then check out your choice of flights. Select from return, one way or multi-city flights, and use the advance search tool if you want a direct or refundable flight. You can narrow your search to show you just your preferred cabin class and airline, too. It’s all easy. You can book direct flights from Denver to St. Louis that take around hours.

Find cheap flights from Denver to St. Louis

From the great flight deals with prices currently ranging from AU$448 to AU$832, you can choose to see the cheapest flights first. Generally, you can book the cheapest flights from Denver to St. Louis around 4 to 6 weeks in advance. If your travel dates are flexible, try to avoid weekends and peak seasons – when you are more likely to grab the lowest prices. Even last minute, there are some impressive deals. The cheapest time to fly to St. Louis is normally in September.

Reasons to book your flight from Denver to St. Louis with Expedia

Expedia makes it easy to find, book, and travel, with everything you need all in one place. When you enter your travel details, find fantastic deals just for you on flight tickets from Denver to St. Louis across all the main airline carriers, so you can save time, dollars, and hassle finding the perfect flight. If you think your plans could change, choose refundable flights so any changes won’t cost you more. Book your flight to St. Louis right now and, if you join Expedia Rewards, you earn points this time and every time you travel with Expedia.

Your quick guide to flights from Denver to St. Louis

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