HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
St. Louis

$71+ 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 10/8. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — STL
черв. 15 — черв. 221
нд 6/15
нд 6/22
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Denver to St. Louis with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

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 Saturday or Friday and return on a Wednesday

Cheap 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 червень 10, 2025.

Round-trip from

$129
(Frontier)

One-way from

$71
(Kiwi.com)

Popular in

June

Cheapest in

January

Average price

$277

Good round-trip deal

$186 or less

Good one-way deal

$131 or less
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. 6% potential increase in price ($14 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 June 2025
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

Find 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 червень 10, 2025.

This Frontier deal was found by Cheapflights users on 6/10. 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.
пт 9/126:00 amDEN - STL
Nonstop2h 07mFrontier
чт 9/187:52 pmSTL - DEN
Nonstop2h 28mFrontier
Deal found 6/10$129
This Southwest deal was found by Cheapflights users on 6/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
чт 8/147:45 amDEN - STL
Nonstop2h 05mSouthwest
нд 8/176:00 amSTL - DEN
Nonstop2h 15mSouthwest
Deal found 6/8$177
This American Airlines deal was found by Cheapflights users on 6/9. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
сб 8/237:22 amDEN - STL
1 stop7h 27mAmerican Airlines
ср 8/2710:08 amSTL - DEN
1 stop4h 47mAmerican Airlines
Deal found 6/9$182
This Delta deal was found by Cheapflights users on 6/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
пт 9/1212:59 amDEN - STL
1 stop7h 41mDelta
вт 9/162:15 pmSTL - DEN
1 stop5h 55mDelta
Deal found 6/10$197
This United Airlines deal was found by Cheapflights users on 6/10. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
вт 7/88:40 pmDEN - STL
Nonstop2h 19mUnited Airlines
вт 7/155:31 pmSTL - DEN
1 stop6h 51mUnited Airlines
Deal found 6/10$289

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 червень 10, 2025.
Use the filters below to find and compare flights from Denver to St. Louis that are best for you.

Fly from

Denver

Fly to

St. Louis

Route

Depart

Return

Price

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

пт 9/12

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

чт 9/18

7:52 pm-9:20 pm

Nonstop2h 28m

$129

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

чт 8/14

7:45 am-10:50 am

Nonstop2h 05m

Lambert-St Louis

нд 8/17

6:00 am-7:15 am

Nonstop2h 15m

$177

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

сб 8/23

7:22 am-3:49 pm

1 stop7h 27m

Lambert-St Louis

ср 8/27

10:08 am-1:55 pm

1 stop4h 47m

$182

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

пт 9/12

12:55 am-9:35 am

1 stop7h 40m

Lambert-St Louis

пн 9/22

5:40 pm-10:15 pm

1 stop5h 35m

$197

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

вт 7/8

8:40 pm-11:59 pm

Nonstop2h 19m

Lambert-St Louis

вт 7/15

5:15 am-6:52 am

Nonstop2h 37m

$279

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

ср 10/8

12:59 am-10:07 am

1 stop8h 08m

$71

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

вт 8/5

8:40 pm-11:59 pm

Nonstop2h 19m

$79

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

ср 10/15

11:59 pm-8:08 am

1 stop7h 09m

$88

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

ср 7/9

6:00 am-2:36 pm

1 stop7h 36m

$99

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

нд 10/12

6:25 am-12:00 pm

1 stop4h 35m

$129

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/10

Showing 1-10 of 12 results
1
2

The best insider tips for Denver to St. Louis flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your Denver to St. Louis trip
Airports
DEN

For a quick security experience at DEN, use the South checkpoint, which is open 24 hours. Reserve a time online for general screening.

Read more about DENby Emily Zemler
STL

Use the MetroLink from STL for a 40-minute ride to downtown St. Louis. It's economical and avoids traffic, ideal for light luggage.

Read more about STLby Taryn White
Our travel experts
Taryn White

Taryn White

Expert on STL

Taryn White

Taryn White

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 Zemler

Emily Zemler

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

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 June 9, 2025.

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, August is the cheapest month in which you can book a flight from Denver to St. Louis (average of $311). Flying from Denver to St. Louis in March is currently the most expensive (average of $356). 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 червень 10, 2025.

It’s optimal to fly from Denver to St. Louis in the evening. By choosing this option you can save up to 35% 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 June 8, 2025.

Travelers seeking maximum savings on their Denver to St. Louis flight should consider departing on Friday evenings 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.

Weekly flight availability from Denver to St. Louis

Explore weekly flight availability from Denver to St. Louis. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated червень 10, 2025.

The most flights from DEN to STL are scheduled on a Monday (16 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (7 on average).

Rainfall in St. Louis by month

Plan your trip to St. Louis by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in St. Louis ranges from 2.2 - 4.7 inches per month. May is typically the wettest month, when rainfall can reach 4.7 in. February is typically the driest time to visit St. Louis when rainfall is around 2.2 in.

Temperature in St. Louis by month

Plan your trip to St. Louis by taking into account the average temperature totals by month.

If weather is an important factor for your trip to St. Louis, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 32.0 F).

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 червень 10, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Southwest and Delta from Denver to St. Louis by reading reviews from past customers. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,289 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,951 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,784 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

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 2h 00m on average. When it comes time to book airfare, you have a few options: there are 13 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, 26 users have taken a look at flights from Denver Intl to Lambert-St Louis.

  • 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 $129 on this airline. Additional options worth looking into are Southwest and American Airlines, starting at $177 and $182 round-trip. Frontier is currently priced 39% 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 $71. Users have also found prices from $79 and $88 on United Airlines and American 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 (85%), Air Canada (71%), United Airlines (66%).

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

    While on average a flight from Denver to St. Louis is generally $241, our data shows the cheapest flight currently is $74. When looking at the most popular route, (Denver Intl - Lambert-St Louis), you can expect to pay $146 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, August is the cheapest month in which you can book a flight from Denver to St. Louis (average of $311). Flying from Denver to St. Louis in March is currently the most expensive (average of $356). 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 Denver?

Book flights to Denver if you plan to visit one of these locations
O'Fallon
Maryland Heights
Fairview Heights
Collinsville
Eureka
St. Peters
Glencoe
Festus
Alton
Farmington

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Denver to St. Louis

See prices for flight routes from nearby airports that may be better suited for you.
Denver to Kansas City flights
Denver to Springfield flights
Colorado Springs to St. Louis flights
Durango to St. Louis flights
Montrose to Kansas City flights
Denver to Joplin flights
Colorado Springs to Springfield flights
Grand Junction to Kansas City flights
Aspen to Kansas City flights
Colorado Springs to Kansas City flights
Montrose to St. Louis flights
Denver to Columbia flights
Montrose to Springfield flights
Vail to St. Louis flights
Hayden to Kansas City flights
Grand Junction to Springfield flights
Aspen to St. Louis flights
Grand Junction to Joplin flights
Grand Junction to St. Louis flights
Durango to Kansas City flights
Colorado Springs to Joplin flights
Vail to Kansas City flights
Hayden to St. Louis flights
Montrose to Joplin flights
Durango to Springfield flights
Gunnison to St. Louis flights
Denver to Branson flights
Colorado Springs to Columbia flights

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 червень 10, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$45Average$146FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$150Average$316FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$177Average$301FlexibilityNo cancel feeOn-time63%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.
Site
Privacy Preferences©2025 Cheapflights