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St. Louis

$43+ Cheap flights from Denver to St. Louis (DEN - STL)

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 5/10. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — STL
Apr 2 — Apr 91
Thu 4/2
Thu 4/9
1 adult, Economy
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Find cheap flights from Denver to St. Louis with Cheapflights

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Cheapflights Tip: The best prices from Denver Intl to Lambert-St Louis are usually found in January or August, booked 74 days in advance, depart on a Friday or Saturday and return on a Wednesday

Cheap flight deals from Denver to St. Louis

Cheapest flights from Denver to St. Louis
Explore the most affordable flight options available from Denver to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 3, 2026.

This Super.com deal was found by Cheapflights users on 2/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/274:20 pm
DEN
-
STL
Nonstop2h 12m
Frontier
Fri 5/18:06 pm
STL
-
DEN
Nonstop2h 33m
Frontier
Deal found 2/28$87
This Frontier deal was found by Cheapflights users on 2/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/16:40 am
DEN
-
STL
Nonstop2h 08m
Frontier
Sat 4/48:16 pm
STL
-
DEN
Nonstop2h 33m
Frontier
Deal found 2/28$88
This Super.com deal was found by Cheapflights users on 2/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/184:20 pm
DEN
-
STL
Nonstop2h 12m
Frontier
Mon 4/278:17 pm
STL
-
DEN
Nonstop2h 33m
Frontier
Deal found 2/27$89
This Super.com deal was found by Cheapflights users on 3/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/136:40 am
DEN
-
STL
Nonstop2h 08m
Frontier
Sat 4/188:17 pm
STL
-
DEN
Nonstop2h 33m
Frontier
Deal found 3/1$91
This Super.com deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/36:40 am
DEN
-
STL
Nonstop2h 08m
Frontier
Mon 4/68:19 pm
STL
-
DEN
Nonstop2h 33m
Frontier
Deal found 3/3$96
This Cheapflightsfares deal was found by Cheapflights users on 2/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/66:40 am
DEN
-
STL
Nonstop2h 08m
Frontier
Wed 4/88:16 pm
STL
-
DEN
Nonstop2h 33m
Frontier
Deal found 2/27$97
This Frontier deal was found by Cheapflights users on 2/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/16:40 am
DEN
-
STL
Nonstop2h 08m
Frontier
Mon 4/68:19 pm
STL
-
DEN
Nonstop2h 33m
Frontier
Deal found 2/26$102
This Kiwi.com deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/276:35 am
DEN
-
STL
Nonstop2h 14m
Frontier
Sat 3/288:12 pm
STL
-
DEN
Nonstop2h 37m
Frontier
Deal found 3/3$106
This Cheapflightsfares deal was found by Cheapflights users on 2/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/184:20 pm
DEN
-
STL
Nonstop2h 12m
Frontier
Sun 4/199:55 pm
STL
-
DEN
1 stop7h 04m
Frontier
Deal found 2/27$107
This Frontier deal was found by Cheapflights users on 2/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/169:00 pm
DEN
-
STL
1 stop9h 54m
Frontier
Sat 4/188:17 pm
STL
-
DEN
Nonstop2h 33m
Frontier
Deal found 2/26$108
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/1010:40 pm
DEN
-
STL
1 stop12h 41m
Frontier
Mon 4/138:19 pm
STL
-
DEN
Nonstop2h 33m
Frontier
Deal found 3/2$109
This Cheapflightsfares deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/166:35 am
DEN
-
STL
Nonstop2h 14m
Frontier
Wed 3/1811:32 am
STL
-
DEN
1 stop12h 32m
Frontier
Deal found 3/2$113

Find flight deals from Denver to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Denver (DEN) 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 March 3, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$87
(Super.com)

One-way from

$43
(Kiwi.com)

Popular in

June

Cheapest in

January

Average price

$287

Good round-trip deal

$235 or less

Good one-way deal

$148 or less
Provider with most accurate pricing for Denver Intl-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Denver Intl-Lambert-St Louis flights.
Search Deals
From Denver Intl to Lambert-St Louis
Search Deals
One-way flight from Denver Intl to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 7% potential increase in price ($19 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($6 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
Search Deals
Price to beat on a round-trip flight from Denver Intl to Lambert-St Louis.
Search Deals
Price to beat on a one-way flight from Denver Intl to Lambert-St Louis.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Denver 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 2,558,603 searches. Data last updated March 3, 2026.
Use the filters below to find and compare flights from Denver to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Tue 3/31

5:45 pm-8:54 pm

Nonstop2h 09m

Lambert-St Louis

Tue 4/7

8:54 am-10:27 am

Nonstop2h 33m

$177

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Wed 4/29

3:20 pm-9:13 pm

1 stop4h 53m

Lambert-St Louis

Wed 5/6

5:59 pm-7:32 pm

Nonstop2h 33m

$211

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Mon 5/4

6:27 pm-12:25 am

1 stop4h 58m

Lambert-St Louis

Wed 5/6

6:00 am-1:32 pm

1 stop8h 32m

$265

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Mon 5/4

5:34 pm-8:43 pm

Nonstop2h 09m

Lambert-St Louis

Wed 5/6

7:09 pm-11:50 pm

1 stop5h 41m

$287

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Thu 4/2

5:45 pm-8:54 pm

Nonstop2h 09m

Lambert-St Louis

Mon 4/6

6:05 pm-7:39 pm

Nonstop2h 34m

$295

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Fri 4/3

5:45 pm-8:54 pm

Nonstop2h 09m

Lambert-St Louis

Tue 4/7

4:30 pm-6:04 pm

Nonstop2h 34m

$297

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Fri 4/3

4:00 pm-12:21 am

1 stop7h 21m

Lambert-St Louis

Sun 4/5

6:29 am-10:32 am

1 stop5h 03m

$302

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Sun 3/29

7:45 am-10:50 am

Nonstop2h 05m

Lambert-St Louis

Tue 3/31

12:10 pm-1:30 pm

Nonstop2h 20m

$307

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Thu 4/9

5:45 pm-8:54 pm

Nonstop2h 09m

Lambert-St Louis

Mon 4/13

6:05 pm-7:39 pm

Nonstop2h 34m

$322

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Thu 5/21

6:20 am-9:25 am

Nonstop2h 05m

Lambert-St Louis

Mon 5/25

8:25 am-9:45 am

Nonstop2h 20m

$327

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/3

Showing 1-10 of 21 resultsSorted by cheapest first
1
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Compare providers for flights from Denver to St. Louis

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Denver to St. Louis in March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
JustAirTicketPrice Accuracy-Trust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy1 starTrust Score*2 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Denver-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Denver-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Denver-St. Louis flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Denver-St. Louis flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Denver-St. Louis flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Denver to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Denver 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 Denver to St. Louis

How far ahead should I book a flight from Denver to St. Louis?

Use this chart to determine the optimal time to book a round-trip flight from Denver to St. Louis. Price data was last updated on February 27, 2026.

The price you pay for your flight from Denver to St. Louis may vary depending on when you book. For the best chance of a lower fare, look to book 74 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Denver to St. Louis?

Currently, February is the cheapest month in which you can book a flight from Denver to St. Louis (average of $42). Flying from Denver to St. Louis in July is currently the most expensive (average of $134). 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 DEN to STL?

Find hourly flight availability from Denver 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 March 3, 2026.

It’s optimal to fly from Denver to St. Louis in the morning. By choosing this option you can save up to 13% on the cost of your flight, compared to a flight at noon.

What is the cheapest day to fly from Denver to St. Louis?

Use this chart to determine the cheapest time to fly round-trip from Denver to St. Louis. Price data was last updated on February 21, 2026.

Travelers seeking maximum savings on their Denver to St. Louis flight should consider departing on Friday mornings when fares are most often at their lowest. Monday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

The best insider tips for Denver to St. Louis flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Denver to St. Louis trip
Our travel experts
Taryn White

Taryn White

Expert on STL

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Read more
Emily Zemler

Emily Zemler

Expert on DEN

Emily is a freelance writer and book author based in London covering entertainment and travel. Her work has appeared in Los Angeles Times, Observer, and Conde Nast Traveler She has ventured to more than 40 countries and all seven continents, always in search of a great art museum. She has written extensively about hotels, luxury travel, and aviation.

Read more

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 March 3, 2026.
Get a feel of what it's like to fly with Southwest, United Airlines, and Frontier from Denver to St. Louis by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,301 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Food

7.0

Overall

8.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Feb 2026

DEN - BDL

Weird they cancelled a direct and rerouted me on a connecting flight to get in 10 hours later. What was the point? Crew and flight were great, but not sure what's going on with Southwest.
Southwest
8.0
Very good
4,301 reviews
Southwest
8.0
Very good
4,301 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Food

7.0

Overall

8.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Feb 2026

DEN - BDL

Weird they cancelled a direct and rerouted me on a connecting flight to get in 10 hours later. What was the point? Crew and flight were great, but not sure what's going on with Southwest.
United Airlines
7.4
Good
9,378 reviews
Southwest
8.0
Very good
4,301 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Food

7.0

Overall

8.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Feb 2026

DEN - BDL

Weird they cancelled a direct and rerouted me on a connecting flight to get in 10 hours later. What was the point? Crew and flight were great, but not sure what's going on with Southwest.
Frontier
5.7
Fair
3,041 reviews
Southwest
8.0
Very good
4,301 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Food

7.0

Overall

8.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Feb 2026

DEN - BDL

Weird they cancelled a direct and rerouted me on a connecting flight to get in 10 hours later. What was the point? Crew and flight were great, but not sure what's going on with Southwest.

Related info for your journey

Find useful and relevant information for your journey from Denver 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 airports do I use to fly from Denver to St. Louis?

    To fly from Denver to St. Louis, you need to book a flight from Denver Intl (DEN) to Lambert-St Louis (STL). Nonstop flights to Lambert-St Louis from Denver Intl take 1h 58m on average. When it comes time to book airfare, you have a few options: there are 3 outbound flights from Denver Intl to Lambert-St Louis offered by 3 different airlines.

  • How popular is this Denver to St. Louis flight route?

    Within the past month, 30 users have taken a look at flights from Denver Intl to Lambert-St Louis.

  • How long is the flight from Denver to St. Louis?

    A quick flight from Denver to St. Louis can take about 2h 09m. United Airlines provides one of the quickest options available for as low as $177. The distance from Denver to St. Louis is about 767 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the cheapest airlines flying from Denver to St. Louis round-trip?

    Our cheapest airline available from Denver to St. Louis is Frontier. Our recent data shows that you can find tickets from as low as $58 on this airline. Additional options worth looking into are United Airlines and Southwest, starting at $165 and $177 round-trip. Frontier is currently priced 76% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from Denver to St. Louis one-way?

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $29. Users have also found prices from $84 and $108 on Southwest and United Airlines, respectively.

  • What are the most reliable airlines from Denver to St. Louis?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Denver to St. Louis on time: Frontier (92%), Volaris (91%), Air Canada (87%).

  • What are the cheapest flights from Denver to St. Louis?

    While on average a flight from Denver to St. Louis is generally $246, our data shows the cheapest flight currently is $49. When looking at the most popular route, (Denver Intl - Lambert-St Louis), you can expect to pay $72 for that flight.

  • Can I find deals for flights from Denver to St. Louis that include hotel bookings?

    Yes. In addition to deals on Denver to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Denver to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Denver to St. Louis.

  • Can I find deals for business class flights from Denver to St. Louis?

    Yes. Cheapflights offers flight deals from Denver 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 Denver to St. Louis?

    Currently, February is the cheapest month in which you can book a flight from Denver to St. Louis (average of $42). Flying from Denver to St. Louis in July is currently the most expensive (average of $134). 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

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fenton
Swansea
Fairview Heights
Maryland Heights
Collinsville
Eureka
Wentzville
Glencoe
Chesterfield
Alton
Farmington
Festus

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Top 3 airlines flying from Denver to St. Louis

Discover the top 3 airlines that operate flights from Denver 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 2,558,603 searches. Data last updated March 3, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$58Average$166FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$165Average$316FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$177Average$316FlexibilityNo cancel feeOn-time63%

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