$86+ Cheap flights from St. Louis to Denver (STL - DEN)
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 10/9. Fares are subject to change and may not be available on all flights or dates of travel.
STL — DEN
Sep 9 — Sep 161
Round-trip
1 adult, Economy
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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 October or November, booked 35 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 August 10, 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 August 10, 2026.
This Cheapflightsfares deal was found by Cheapflights users on 8/5. 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 8/277:58 pm -
Nonstop2h 27m
Thu 9/34:00 pm -
Nonstop2h 13m
Deal found 8/5![Frontier logo]()
$137
This Cheapflightsfares deal was found by Cheapflights users on 8/7. 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 9/168:10 pm -
Nonstop2h 29m
Thu 9/246:38 pm -
1 stop15h 39m
Deal found 8/7![Frontier logo]()
$139
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 9/168:10 pm -
Nonstop2h 29m
Tue 9/227:10 pm -
1 stop17h 00m
Deal found 8/6![Frontier logo]()
$140
This Frontier deal was found by Cheapflights users on 8/6. 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 9/168:10 pm -
Nonstop2h 29m
Sat 9/269:19 pm -
1 stop11h 16m
Deal found 8/6![Frontier logo]()
$141
This Kiwi.com deal was found by Cheapflights users on 8/5. 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 10/308:10 pm -
Nonstop2h 39m
Mon 11/24:12 pm -
Nonstop2h 03m
Deal found 8/5![Frontier logo]()
$142
This Cheapflightsfares deal was found by Cheapflights users on 8/7. 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 9/258:10 pm -
Nonstop2h 29m
Wed 9/304:12 pm -
Nonstop2h 05m
Deal found 8/7![Frontier logo]()
$143
This Cheapflightsfares deal was found by Cheapflights users on 8/5. 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 9/118:10 pm -
Nonstop2h 29m
Mon 9/149:43 am -
1 stop24h 49m
Deal found 8/5![Frontier logo]()
$144
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/118:10 pm -
Nonstop2h 29m
Tue 10/67:10 pm -
1 stop17h 00m
Deal found 8/8![Frontier logo]()
$145
This Frontier deal was found by Cheapflights users on 8/8. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/131:02 pm -
Nonstop2h 24m
Sat 10/34:12 pm -
Nonstop2h 05m
Deal found 8/8![Frontier logo]()
$146
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/112:29 pm -
1 stop7h 55m
Sat 10/34:12 pm -
Nonstop2h 05m
Deal found 8/8![Frontier logo]()
$147
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/112:29 pm -
1 stop7h 55m
Mon 10/54:12 pm -
Nonstop2h 05m
Deal found 8/8![Frontier logo]()
$148
This Kiwi.com deal was found by Cheapflights users on 8/5. 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 10/52:29 pm -
1 stop18h 35m
Mon 10/124:12 pm -
Nonstop2h 03m
Deal found 8/5![Frontier logo]()
$149
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 August 10, 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 August 10, 2026.
This Southwest deal was found by Cheapflights users on 8/4. 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.
Tue 1/511:20 am -
Nonstop2h 25m
Sat 1/96:45 am -
Nonstop2h 05m
Deal found 8/4![Southwest logo]()
$213
This Delta deal was found by Cheapflights users on 8/4. 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.
Tue 1/56:59 pm -
1 stop6h 24m
Sat 1/95:40 am -
1 stop6h 43m
Deal found 8/4![Delta logo]()
$233
This United Airlines deal was found by Cheapflights users on 8/8. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/54:40 pm -
Nonstop2h 30m
Sat 9/128:25 pm -
Nonstop2h 15m
Deal found 8/8![United Airlines logo]()
$282
This Southwest deal was found by Cheapflights users on 8/5. 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.
Tue 10/276:10 pm -
Nonstop2h 20m
Wed 10/281:30 pm -
1 stop3h 15m
Deal found 8/5![Southwest logo]()
$219
This Southwest deal was found by Cheapflights users on 8/6. 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 9/52:15 pm -
1 stop3h 40m
Sat 9/127:15 am -
2 stops7h 15m
Deal found 8/6![Southwest logo]()
$225
This Southwest deal was found by Cheapflights users on 8/7. 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 10/101:50 pm -
1 stop4h 30m
Sat 10/1712:30 pm -
2 stops6h 50m
Deal found 8/7![Southwest logo]()
$238
This United Airlines deal was found by Cheapflights users on 8/7. 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 11/114:39 pm -
Nonstop2h 31m
Sat 11/141:55 pm -
Nonstop2h 02m
Deal found 8/7![United Airlines logo]()
$293
This United Airlines deal was found by Cheapflights users on 8/4. 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 8/261:36 pm -
Nonstop2h 24m
Sat 8/291:27 pm -
Nonstop2h 07m
Deal found 8/4![United Airlines logo]()
$293
This Southwest deal was found by Cheapflights users on 8/5. 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.
Fri 9/48:45 pm -
Nonstop2h 20m
Tue 9/83:40 pm -
Nonstop2h 05m
Deal found 8/5![Southwest logo]()
$315
This United Airlines deal was found by Cheapflights users on 8/5. 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.
Sun 10/45:10 am -
Nonstop2h 33m
Wed 10/75:30 pm -
Nonstop2h 06m
Deal found 8/5![United Airlines logo]()
$375
This Southwest deal was found by Cheapflights users on 8/8. 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.
Fri 9/256:05 pm -
Nonstop2h 15m
Mon 9/288:05 pm -
Nonstop2h 10m
Deal found 8/8![Southwest logo]()
$377
Last-minute flights from St. Louis to DenverDiscover last-minute flight deals from St. Louis to Denver. Data last updated August 10, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Denver. Data last updated August 10, 2026 and is based on user searches.
This Cheapflightsfares deal was found by Cheapflights users on 8/5. 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 8/277:58 pm -
Nonstop2h 27m
Thu 9/34:00 pm -
Nonstop2h 13m
Deal found 8/5![Frontier logo]()
$137
This Cheapflightsfares deal was found by Cheapflights users on 8/5. 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 9/118:10 pm -
Nonstop2h 29m
Mon 9/149:43 am -
1 stop24h 49m
Deal found 8/5![Frontier logo]()
$144
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/118:10 pm -
Nonstop2h 29m
Tue 10/67:10 pm -
1 stop17h 00m
Deal found 8/8![Frontier logo]()
$145
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/112:29 pm -
1 stop7h 55m
Sat 10/34:12 pm -
Nonstop2h 05m
Deal found 8/8![Frontier logo]()
$147
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/112:29 pm -
1 stop7h 55m
Mon 10/54:12 pm -
Nonstop2h 05m
Deal found 8/8![Frontier logo]()
$148
This Frontier deal was found by Cheapflights users on 8/8. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/131:02 pm -
Nonstop2h 24m
Mon 10/54:12 pm -
Nonstop2h 05m
Deal found 8/8![Frontier logo]()
$146
This Cheapflightsfares deal was found by Cheapflights users on 8/7. 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 9/1612:17 pm -
1 stop12h 27m
Wed 9/234:12 pm -
Nonstop2h 05m
Deal found 8/7![Frontier logo]()
$139
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 9/168:10 pm -
Nonstop2h 29m
Tue 9/227:10 pm -
1 stop17h 00m
Deal found 8/6![Frontier logo]()
$140
This Frontier deal was found by Cheapflights users on 8/6. 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 9/168:10 pm -
Nonstop2h 29m
Sat 9/269:19 pm -
1 stop11h 16m
Deal found 8/6![Frontier logo]()
$141
This Cheapflightsfares deal was found by Cheapflights users on 8/7. 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 9/258:10 pm -
Nonstop2h 29m
Wed 9/304:12 pm -
Nonstop2h 05m
Deal found 8/7![Frontier logo]()
$143
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 August 10, 2026.
Search for one-way flight options from St. Louis to Denver. Find affordable one-way fares based on user searches. Data last updated August 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 8/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/910:35 am -
1 stop12h 58m
Deal found 8/9![Frontier logo]()
$86
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 10/22:29 pm -
1 stop18h 35m
Deal found 8/6![Frontier logo]()
$89
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 8/276:17 pm -
1 stop16h 02m
Deal found 8/6![Frontier logo]()
$94
This Kiwi.com deal was found by Cheapflights users on 8/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/1010:35 am -
1 stop12h 58m
Deal found 8/9![Frontier logo]()
$96
This Frontier deal was found by Cheapflights users on 8/7. 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 10/72:29 pm -
1 stop7h 34m
Deal found 8/7![Frontier logo]()
$97
This Kiwi.com deal was found by Cheapflights users on 8/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/68:10 pm -
Nonstop2h 39m
Deal found 8/9![Frontier logo]()
$98
This Cheapflightsfares deal was found by Cheapflights users on 8/7. 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 9/188:10 pm -
Nonstop2h 29m
Deal found 8/7![Frontier logo]()
$99
This Super.com deal was found by Cheapflights users on 8/5. 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.
Wed 11/45:32 pm -
1 stop26h 08m
Deal found 8/5![Frontier logo]()
$101
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/1410:35 am -
1 stop12h 58m
Deal found 8/8![Frontier logo]()
$102
This Delta deal was found by Cheapflights users on 8/7. 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.
Sun 9/66:30 am -
1 stop7h 47m
Deal found 8/7![Delta logo]()
$104
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 August 10, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $137 (Cheapflightsfares) |
One-way from | $86 (Kiwi.com) |
Popular in | June |
Cheapest in | October |
Average price | $246 |
Good round-trip deal | $297 or less |
Good one-way deal | $189 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 2,558,603 searches. Data last updated August 10, 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
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Tue 1/5
11:20 am-12:45 pm
Nonstop2h 25m
Denver Intl
Sat 1/9
6:45 am-9:50 am
Nonstop2h 05m
$213
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Tue 10/27
6:10 pm-7:30 pm
Nonstop2h 20m
Denver Intl
Wed 10/28
1:30 pm-5:45 pm
1 stop3h 15m
$219
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Sat 9/5
2:15 pm-4:55 pm
1 stop3h 40m
Denver Intl
Sat 9/12
7:15 am-3:30 pm
2 stops7h 15m
$225
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Tue 1/5
6:59 pm-12:23 am
1 stop6h 24m
Denver Intl
Sat 1/9
5:40 am-1:23 pm
1 stop6h 43m
$233
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Sat 10/10
1:50 pm-5:20 pm
1 stop4h 30m
Denver Intl
Sat 10/17
12:30 pm-8:20 pm
2 stops6h 50m
$238
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Sat 9/5
4:40 pm-6:10 pm
Nonstop2h 30m
Denver Intl
Sat 9/12
8:25 pm-11:40 pm
Nonstop2h 15m
$282
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Wed 11/11
4:39 pm-6:10 pm
Nonstop2h 31m
Denver Intl
Sat 11/14
1:55 pm-4:57 pm
Nonstop2h 02m
$293
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Wed 8/26
1:36 pm-3:00 pm
Nonstop2h 24m
Denver Intl
Sat 8/29
1:27 pm-4:34 pm
Nonstop2h 07m
$293
Quickest round-trip
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Fri 9/4
8:45 pm-10:05 pm
Nonstop2h 20m
Denver Intl
Tue 9/8
3:40 pm-6:45 pm
Nonstop2h 05m
$315
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Sun 10/4
5:10 am-6:43 am
Nonstop2h 33m
Denver Intl
Wed 10/7
5:30 pm-8:36 pm
Nonstop2h 06m
$375
Showing 1-10 of 21 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 August.
| 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 Accuracy2 stars | Trust Score*1 star | |
| Price Accuracy- | Trust Score*3 stars | |
| Price Accuracy1 star | 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
How far ahead should I book a flight from St. Louis to Denver?
Booking 34 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, October is the cheapest month in which you can book a flight from St. Louis to Denver (average of $184). 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 August 10, 2026.
It’s optimal to fly from St. Louis to Denver in the evening. By choosing this option you can save up to 50% 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 August 8, 2026.
Travelers seeking maximum savings on their St. Louis to Denver flight should consider departing on Tuesday 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
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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 August 10, 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
7.5
Overall
8.0
Comfort
8.0
Food
7.0
Boarding
8.1
Crew
8.6
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Overall
8.0
Comfort
8.0
Food
7.0
Boarding
8.1
Crew
8.6
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Overall
8.0
Comfort
8.0
Food
7.0
Boarding
8.1
Crew
8.6
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Overall
8.0
Comfort
8.0
Food
7.0
Boarding
8.1
Crew
8.6
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
Black Hawk
Lakewood
Centennial
Broomfield
Golden
Wheat Ridge
Silverthorne
Central City
Fort Morgan
Cripple Creek
Greeley
Winter Park
Limon
Manitou Springs
Frisco
Englewood
Glendale
Evergreen
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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 2,558,603 searches. Data last updated August 10, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$56 | Average$166 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$173 | Average$334 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$187 | Average$342 | FlexibilityNo cancel fee | On-time63% |