$43+ Cheap flights from St. Louis to Denver (STL - DEN)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/6. Fares are subject to change and may not be available on all flights or dates of travel.
STL — DEN
Nov 16 — Nov 231
Round-trip
1 adult, Economy
We work with more than 300 partners to bring you better travel deals
Find cheap flights from St. Louis to Denver 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 Lambert-St Louis to Denver Intl are usually found in January or November, booked 18 days in advance, depart on a Saturday or Wednesday and return on a Saturday
Cheap flight deals from St. Louis to Denver
Cheapest
Best
Last-minute
One-way
Cheapest flights from St. Louis to DenverExplore the most affordable flight options available from St. Louis to Denver. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 17, 2026.
Explore the most affordable flight options available from St. Louis to Denver. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 17, 2026.
This Cheapflightsfares deal was found by Cheapflights users on 10/12. 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.
Thu 11/512:14 pm -
1 stop10h 20m
Mon 11/94:09 pm -
Nonstop2h 05m
Deal found 10/12![Frontier logo]()
$138
This Super.com deal was found by Cheapflights users on 10/12. 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 11/67:59 pm -
Nonstop2h 31m
Mon 11/910:41 am -
1 stop6h 01m
Deal found 10/12![Frontier logo]()
$139
This Kiwi.com deal was found by Cheapflights users on 10/13. 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.
Wed 12/27:58 pm -
Nonstop2h 31m
Mon 12/78:40 pm -
2 stops37h 37m
Deal found 10/13![Frontier logo]()
$140
This Kiwi.com deal was found by Cheapflights users on 10/13. 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.
Thu 11/1911:40 am -
Nonstop2h 32m
Wed 11/257:55 am -
Nonstop2h 08m
Deal found 10/13![Frontier logo]()
$141
This Kiwi.com deal was found by Cheapflights users on 10/15. 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.
Mon 11/231:20 pm -
1 stop10h 22m
Fri 11/277:55 am -
Nonstop2h 08m
Deal found 10/15![Frontier logo]()
$142
This Cheapflightsfares deal was found by Cheapflights users on 10/16. 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.
Fri 11/137:59 pm -
Nonstop2h 31m
Mon 11/166:40 am -
1 stop15h 36m
Deal found 10/16![Frontier logo]()
$144
This Cheapflightsfares deal was found by Cheapflights users on 10/12. 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 11/97:59 pm -
Nonstop2h 31m
Mon 11/164:09 pm -
Nonstop2h 05m
Deal found 10/12![Frontier logo]()
$146
This Kiwi.com deal was found by Cheapflights users on 10/15. 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 11/137:59 pm -
Nonstop2h 31m
Sun 11/156:30 am -
1 stop27h 49m
Deal found 10/15![Frontier logo]()
$149
This Frontier deal was found by Cheapflights users on 10/12. 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 11/184:18 pm -
Nonstop2h 30m
Mon 11/239:26 pm -
1 stop9h 28m
Deal found 10/12![Frontier logo]()
$150
Best flights from St. Louis to DenverDiscover carefully curated flight deals from St. Louis to Denver that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 17, 2026.
Discover carefully curated flight deals from St. Louis to Denver that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 17, 2026.
This Southwest deal was found by Cheapflights users on 10/12. 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.
Thu 11/129:45 pm -
Nonstop2h 30m
Mon 11/168:10 am -
Nonstop2h 00m
Deal found 10/12![Southwest logo]()
$177
This United Airlines deal was found by Cheapflights users on 10/13. 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.
Wed 11/48:50 am -
Nonstop2h 31m
Tue 11/109:35 am -
Nonstop2h 03m
Deal found 10/13![United Airlines logo]()
$277
This Southwest deal was found by Cheapflights users on 10/12. 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.
Thu 12/242:35 pm -
Nonstop2h 20m
Tue 12/297:50 pm -
Nonstop2h 00m
Deal found 10/12![Southwest logo]()
$177
This United Airlines deal was found by Cheapflights users on 10/15. 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.
Fri 11/61:40 pm -
Nonstop2h 29m
Sun 11/89:35 am -
Nonstop2h 03m
Deal found 10/15![United Airlines logo]()
$284
This Southwest deal was found by Cheapflights users on 10/16. 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.
Sat 11/142:55 pm -
Nonstop2h 25m
Sun 11/158:10 am -
Nonstop2h 05m
Deal found 10/16![Southwest logo]()
$284
This United Airlines deal was found by Cheapflights users on 10/16. 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.
Fri 11/208:50 am -
Nonstop2h 31m
Sun 11/225:54 pm -
Nonstop2h 07m
Deal found 10/16![United Airlines logo]()
$341
This United Airlines deal was found by Cheapflights users on 10/14. 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.
Thu 12/248:48 am -
Nonstop2h 37m
Tue 12/291:55 pm -
Nonstop2h 05m
Deal found 10/14![United Airlines logo]()
$351
This Southwest deal was found by Cheapflights users on 10/16. 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.
Wed 11/259:50 pm -
Nonstop2h 30m
Sun 11/298:55 pm -
Nonstop2h 00m
Deal found 10/16![Southwest logo]()
$374
This United Airlines deal was found by Cheapflights users on 10/15. 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.
Sat 11/78:50 am -
Nonstop2h 31m
Sun 11/89:35 am -
Nonstop2h 03m
Deal found 10/15![United Airlines logo]()
$384
This United Airlines deal was found by Cheapflights users on 10/13. 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.
Thu 11/268:50 am -
Nonstop2h 31m
Sun 11/298:25 pm -
Nonstop2h 07m
Deal found 10/13![United Airlines logo]()
$407
Last-minute flights from St. Louis to DenverDiscover last-minute flight deals from St. Louis to Denver. Data last updated October 17, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Denver. Data last updated October 17, 2026 and is based on user searches.
This Cheapflightsfares deal was found by Cheapflights users on 10/12. 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.
Wed 11/44:18 pm -
Nonstop2h 30m
Sat 11/710:40 am -
1 stop11h 36m
Deal found 10/12![Frontier logo]()
$138
This Kiwi.com deal was found by Cheapflights users on 10/13. 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.
Wed 11/46:44 pm -
2 stops18h 24m
Fri 11/64:09 pm -
Nonstop2h 05m
Deal found 10/13![Frontier logo]()
$152
This Orbitz deal was found by Cheapflights users on 10/13. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/64:26 pm -
1 stop28h 34m
Mon 11/94:09 pm -
Nonstop2h 05m
Deal found 10/13![Frontier logo]()
$140
This Cheapflightsfares deal was found by Cheapflights users on 10/16. 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.
Wed 11/114:18 pm -
Nonstop2h 30m
Fri 11/136:40 am -
1 stop15h 36m
Deal found 10/16![Frontier logo]()
$148
This Cheapflightsfares deal was found by Cheapflights users on 10/15. 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.
Fri 11/137:59 pm -
Nonstop2h 31m
Mon 11/166:40 am -
1 stop15h 36m
Deal found 10/15![Frontier logo]()
$144
This Kiwi.com deal was found by Cheapflights users on 10/15. 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 11/137:59 pm -
Nonstop2h 31m
Sun 11/156:30 am -
1 stop27h 49m
Deal found 10/15![Frontier logo]()
$149
This Frontier deal was found by Cheapflights users on 10/12. 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 11/184:18 pm -
Nonstop2h 30m
Sun 11/2211:59 pm -
1 stop11h 26m
Deal found 10/12![Frontier logo]()
$150
This Kiwi.com deal was found by Cheapflights users on 10/13. 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.
Thu 11/1911:40 am -
Nonstop2h 32m
Wed 11/257:55 am -
Nonstop2h 08m
Deal found 10/13![Frontier logo]()
$141
This Kiwi.com deal was found by Cheapflights users on 10/15. 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.
Mon 11/231:20 pm -
1 stop10h 22m
Fri 11/277:55 am -
Nonstop2h 08m
Deal found 10/15![Frontier logo]()
$142
One-way flights from St. Louis to DenverSearch for one-way flight options from St. Louis to Denver. Find affordable one-way fares based on user searches. Data last updated October 17, 2026.
Search for one-way flight options from St. Louis to Denver. Find affordable one-way fares based on user searches. Data last updated October 17, 2026.
This Super.com deal was found by Cheapflights users on 10/14. 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 11/67:59 pm -
Nonstop2h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/14![Frontier logo]()
$43
This Super.com deal was found by Cheapflights users on 10/12. 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 11/27:59 pm -
Nonstop2h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/12![Frontier logo]()
$44
This Kiwi.com deal was found by Cheapflights users on 10/15. 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.
Wed 12/167:54 pm -
Nonstop2h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/15![Frontier logo]()
$46
This Kiwi.com deal was found by Cheapflights users on 10/12. 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 12/117:54 pm -
Nonstop2h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/12![Frontier logo]()
$48
This Kiwi.com deal was found by Cheapflights users on 10/13. 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.
Wed 1/137:02 pm -
Nonstop2h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/13![Frontier logo]()
$52
This Kiwi.com deal was found by Cheapflights users on 10/14. 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.
Wed 11/114:18 pm -
Nonstop2h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/14![Frontier logo]()
$53
This Frontier deal was found by Cheapflights users on 10/13. 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.
Mon 11/167:59 pm -
Nonstop2h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/13![Frontier logo]()
$54
This Cheapflightsfares deal was found by Cheapflights users on 10/16. 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 12/214:21 pm -
Nonstop2h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/16![Frontier logo]()
$71
This Kiwi.com deal was found by Cheapflights users on 10/12. 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.
Wed 12/912:02 pm -
1 stop8h 53m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/12![Frontier logo]()
$74
This Kiwi.com deal was found by Cheapflights users on 10/16. 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.
Thu 11/1911:29 am -
1 stop22h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/16![Frontier logo]()
$76
This Super.com deal was found by Cheapflights users on 10/13. 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 12/193:52 pm -
1 stop9h 17m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/13![Frontier logo]()
$78
Find flight deals from St. Louis to Denver
Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Denver (DEN). 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 October 17, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $138 (Cheapflightsfares) |
One-way from | $43 (Super.com) |
Popular in | June |
Cheapest in | January |
Average price | $255 |
Good round-trip deal | $311 or less |
Good one-way deal | $191 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from St. Louis to Denver 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 7,457,451 searches. Data last updated October 17, 2026.
Use the filters below to find and compare flights from St. Louis to Denver that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
Quickest round-trip
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Tue 11/10
8:20 pm-9:45 pm
Nonstop2h 25m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$89
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Wed 11/11
2:20 pm-8:29 pm
1 stop7h 09m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$99
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Thu 12/10
6:03 am-10:07 am
1 stop5h 04m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$99
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Fri 1/29
1:55 pm-5:30 pm
1 stop4h 35m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$99
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Sat 1/30
6:55 am-1:55 pm
2 stops8h 00m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$104
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Sat 11/14
8:45 am-2:30 pm
2 stops6h 45m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$104
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Thu 11/19
1:40 pm-3:09 pm
Nonstop2h 29m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$126
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Fri 1/1
6:20 am-10:00 am
1 stop4h 40m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$126
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Wed 11/18
2:25 pm-7:30 pm
1 stop6h 05m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$136
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Thu 11/12
1:40 pm-3:09 pm
Nonstop2h 29m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$139
Showing 1-10 of 22 resultsSorted by cheapest first
Compare providers for flights from St. Louis to Denver
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 St. Louis to Denver in October.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*3 stars | |
| Price Accuracy2 stars | Trust Score*1 star | |
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on St. Louis-Denver flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Denver flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Denver flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on St. Louis-Denver 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 St. Louis-Denver 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 St. Louis to Denver
Have a flexible travel schedule? Discover the best time to fly to Denver from St. Louis with our price prediction graph.
STL-DEN
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 St. Louis to Denver
Prices
Airlines
How far ahead should I book a flight from St. Louis to Denver?
Booking 17 days in advance of your planned departure date is, on average, the best time to get cheap flights from St. Louis to Denver. The general trend is that the closer you book to the departure date, the more expensive your flight will be.
What is the cheapest month to book a flight from St. Louis to Denver?
Currently, January is the cheapest month in which you can book a flight from St. Louis to Denver (average of $213). Flying from St. Louis to Denver in June is currently the most expensive (average of $346). 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 STL to DEN?
Find hourly flight availability from St. Louis to Denver. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 17, 2026.
It’s optimal to fly from St. Louis to Denver in the evening. By choosing this option you can save up to 46% on the cost of your flight, compared to a flight in the morning.
What is the cheapest day to fly from St. Louis to Denver?
Use this chart to determine the cheapest time to fly round-trip from St. Louis to Denver. Price data was last updated on October 10, 2026.
Travelers seeking maximum savings on their St. Louis to Denver flight should consider departing on Saturday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
The best insider tips for St. Louis to Denver 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 St. Louis to Denver trip
Our travel experts
Reviews of airlines servicing Denver
Get insights into the airlines that provide service to Denver. 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 Denver. Reviews last updated October 17, 2026.
Get a feel of what it's like to fly with Southwest,United Airlines, andFrontier from St. Louis to Denver by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Entertainment
7.4
Crew
8.6
Comfort
8.0
Boarding
8.1
Overall
7.9
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.4
Crew
8.6
Comfort
8.0
Boarding
8.1
Overall
7.9
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.4
Crew
8.6
Comfort
8.0
Boarding
8.1
Overall
7.9
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.4
Crew
8.6
Comfort
8.0
Boarding
8.1
Overall
7.9
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Related info for your journey
Find useful and relevant information for your journey from St. Louis to Denver. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Traveling to a place near Denver?
Book flights to Denver if you plan to visit one of these locationsThornton
Westminster
Lakewood
Centennial
Broomfield
Black Hawk
Englewood
Golden
Wheat Ridge
Silverthorne
Central City
Fort Morgan
Greeley
Frisco
Winter Park
Limon
Manitou Springs
Glendale
Cripple Creek
Evergreen
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
Complete your trip
Denver flight routes
Flights by cabin class
Other flight options
Other flights from St. Louis
Popular flights
Alternative routes for St. Louis to Denver
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Denver by adding a car rental and/or hotel reservation to your travel itinerary.
Other flights to Denver
Explore flights to Denver departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on October 17, 2026.
Search flights from St. Louis to Denver by cabin class
Find flights from St. Louis to Denver, based on your preferred cabin class, be it economy, premium economy, business, or first class.
St. Louis and Denver flights
Browse other St. Louis and Denver flight options. Last updated on October 17, 2026.
Other flights from St. Louis
Browse through other flights departing from St. Louis. Flights are based on user searches made on Cheapflights and were last updated on October 17, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Top 3 airlines flying from St. Louis to Denver
Discover the top 3 airlines that operate flights from St. Louis to Denver. 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 7,457,451 searches. Data last updated October 17, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$58 | Average$186 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$186 | Average$341 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$196 | Average$358 | FlexibilityNo cancel fee | On-time63% |