$65+ 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 7/22. Fares are subject to change and may not be available on all flights or dates of travel.
STL — DEN
Jul 28 — Aug 41
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 September, booked 35 days in advance, depart on a Saturday or Wednesday and return on a Friday
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 June 28, 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 June 28, 2026.
This Cheapflightsfares deal was found by Cheapflights users on 6/27. 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.
Tue 7/218:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 7/284:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/27![Frontier logo]()
$162
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 8/48:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 8/114:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/24![Frontier logo]()
$167
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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 8/88:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Mon 8/104:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/24![Frontier logo]()
$168
This Frontier deal was found by Cheapflights users on 6/23. 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 8/68:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Wed 8/124:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/23![Frontier logo]()
$170
This Frontier deal was found by Cheapflights users on 6/25. 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.
Sat 8/18:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Wed 8/54:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/25![Frontier logo]()
$171
This Cheapflightsfares deal was found by Cheapflights users on 6/26. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/58:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Sat 8/84:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/26![Frontier logo]()
$177
This Kiwi.com deal was found by Cheapflights users on 6/24. 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.
Sat 7/188:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 7/216:30 am
DEN
- STL
1 stop10h 07m
Frontier
Deal found 6/24![Frontier logo]()
$180
This Kiwi.com deal was found by Cheapflights users on 6/25. 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.
Sat 10/178:10 pm
STL
- DEN
Nonstop2h 39m
Frontier
Tue 10/206:30 am
DEN
- STL
1 stop26h 10m
Frontier
Deal found 6/25![Frontier logo]()
$181
This Super.com deal was found by Cheapflights users on 6/24. 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.
Tue 8/48:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Sat 8/84:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/24![Frontier logo]()
$183
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 June 28, 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 June 28, 2026.
This United Airlines deal was found by Cheapflights users on 6/23. 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 8/199:30 am
STL
- DEN
1 stop6h 01m
United Airlines
Tue 8/251:27 pm
DEN
- STL
Nonstop2h 07m
United Airlines
Deal found 6/23![United Airlines logo]()
$215
This Southwest deal was found by Cheapflights users on 6/24. 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.
Sun 9/138:45 pm
STL
- DEN
Nonstop2h 15m
Southwest
Sat 9/197:35 am
DEN
- STL
Nonstop2h 00m
Southwest
Deal found 6/24![Southwest logo]()
$286
This Delta deal was found by Cheapflights users on 6/26. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/93:42 pm
STL
- DEN
1 stop7h 35m
Delta
Sat 10/1012:59 am
DEN
- STL
1 stop6h 13m
Delta
Deal found 6/26![Delta logo]()
$387
This United Airlines deal was found by Cheapflights users on 6/28. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/112:59 pm
STL
- DEN
1 stop6h 20m
United Airlines
Tue 9/85:32 pm
DEN
- STL
Nonstop2h 06m
United Airlines
Deal found 6/28![United Airlines logo]()
$215
This United Airlines deal was found by Cheapflights users on 6/24. 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.
Tue 9/224:40 pm
STL
- DEN
Nonstop2h 30m
United Airlines
Wed 9/232:50 pm
DEN
- STL
1 stop7h 09m
United Airlines
Deal found 6/24![United Airlines logo]()
$295
This Southwest deal was found by Cheapflights users on 6/25. 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 7/317:10 pm
STL
- DEN
1 stop4h 50m
Southwest
Tue 8/411:15 am
DEN
- STL
2 stops5h 40m
Southwest
Deal found 6/25![Southwest logo]()
$365
This Southwest deal was found by Cheapflights users on 6/26. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/2410:35 pm
STL
- DEN
Nonstop2h 20m
Southwest
Sun 7/268:45 pm
DEN
- STL
Nonstop2h 10m
Southwest
Deal found 6/26![Southwest logo]()
$367
This United Airlines deal was found by Cheapflights users on 6/24. 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.
Tue 9/225:10 am
STL
- DEN
Nonstop2h 33m
United Airlines
Mon 9/288:28 pm
DEN
- STL
Nonstop2h 16m
United Airlines
Deal found 6/24![United Airlines logo]()
$339
This United Airlines deal was found by Cheapflights users on 6/23. 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 11/261:39 pm
STL
- DEN
Nonstop2h 30m
United Airlines
Mon 11/305:33 pm
DEN
- STL
Nonstop2h 01m
United Airlines
Deal found 6/23![United Airlines logo]()
$340
This Southwest deal was found by Cheapflights users on 6/27. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/222:10 pm
STL
- DEN
1 stop3h 50m
Southwest
Sat 7/2510:10 am
DEN
- STL
2 stops6h 50m
Southwest
Deal found 6/27![Southwest logo]()
$380
This Southwest deal was found by Cheapflights users on 6/24. 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.
Mon 8/108:30 am
STL
- DEN
1 stop3h 30m
Southwest
Fri 8/143:15 pm
DEN
- STL
2 stops5h 50m
Southwest
Deal found 6/24![Southwest logo]()
$381
This United Airlines deal was found by Cheapflights users on 6/25. 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 8/239:00 am
STL
- DEN
Nonstop2h 31m
United Airlines
Tue 8/251:27 pm
DEN
- STL
Nonstop2h 07m
United Airlines
Deal found 6/25![United Airlines logo]()
$366
Last-minute flights from St. Louis to DenverDiscover last-minute flight deals from St. Louis to Denver. Data last updated June 28, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Denver. Data last updated June 28, 2026 and is based on user searches.
This Super.com deal was found by Cheapflights users on 6/25. 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.
Tue 7/148:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Fri 7/174:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/25![Frontier logo]()
$194
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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.
Tue 7/148:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 7/213:10 pm
DEN
- STL
1 stop7h 49m
Frontier
Deal found 6/24![Frontier logo]()
$195
This Super.com deal was found by Cheapflights users on 6/25. 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 7/158:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Wed 7/294:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/25![Frontier logo]()
$168
This Kiwi.com deal was found by Cheapflights users on 6/24. 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.
Sat 7/188:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 7/216:30 am
DEN
- STL
1 stop10h 07m
Frontier
Deal found 6/24![Frontier logo]()
$180
This Cheapflightsfares deal was found by Cheapflights users on 6/27. 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.
Tue 7/218:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 7/284:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/27![Frontier logo]()
$162
This Super.com deal was found by Cheapflights users on 6/27. 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.
Wed 7/228:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Sat 7/254:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/27![Frontier logo]()
$191
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 7/228:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Sun 8/94:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/24![Frontier logo]()
$192
This Kiwi.com deal was found by Cheapflights users on 6/25. 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 7/244:57 pm
STL
- DEN
1 stop17h 06m
Frontier
Tue 7/284:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/25![Frontier logo]()
$196
This Kiwi.com deal was found by Cheapflights users on 6/26. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/288:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Sat 8/111:59 pm
DEN
- STL
1 stop16h 38m
Frontier
Deal found 6/26![Frontier logo]()
$190
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 June 28, 2026.
Search for one-way flight options from St. Louis to Denver. Find affordable one-way fares based on user searches. Data last updated June 28, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/26. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/228:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 6/26![Frontier logo]()
$65
This Super.com deal was found by Cheapflights users on 6/27. 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 7/258:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 6/27![Frontier logo]()
$96
This United Airlines deal was found by Cheapflights users on 6/25. 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.
Tue 8/254:40 pm
STL
- DEN
Nonstop2h 30m
United Airlines
Deal found 6/25![United Airlines logo]()
$103
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 9/2210:35 am
STL
- DEN
1 stop12h 58m
Frontier
Deal found 6/24![Frontier logo]()
$104
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 8/178:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 6/24![Frontier logo]()
$109
This Cheapflightsfares deal was found by Cheapflights users on 6/25. 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 8/18:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 6/25![Frontier logo]()
$111
This Frontier deal was found by Cheapflights users on 6/24. 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 9/218:10 pm
STL
- DEN
Nonstop2h 39m
Frontier
Deal found 6/24![Frontier logo]()
$112
This Delta deal was found by Cheapflights users on 6/25. 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 7/216:21 am
STL
- DEN
1 stop6h 44m
Delta
Deal found 6/25![Delta logo]()
$113
This Kiwi.com deal was found by Cheapflights users on 6/27. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/274:57 pm
STL
- DEN
1 stop17h 06m
Frontier
Deal found 6/27![Frontier logo]()
$117
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 9/2510:35 am
STL
- DEN
1 stop23h 56m
Frontier
Deal found 6/24![Frontier logo]()
$120
This Kiwi.com deal was found by Cheapflights users on 6/28. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/244:57 pm
STL
- DEN
1 stop17h 06m
Frontier
Deal found 6/28![Frontier logo]()
$121
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 June 28, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $162 (Cheapflightsfares) |
One-way from | $65 (Kiwi.com) |
Popular in | June |
Cheapest in | October |
Average price | $338 |
Good round-trip deal | $297 or less |
Good one-way deal | $184 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 June 28, 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 - DEN
STLDEN
Lambert-St Louis
Wed 8/19
9:30 am-2:31 pm
1 stop6h 01m
Denver Intl
Tue 8/25
1:27 pm-4:34 pm
Nonstop2h 07m
$215
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Tue 9/1
12:59 pm-6:19 pm
1 stop6h 20m
Denver Intl
Tue 9/8
5:32 pm-8:38 pm
Nonstop2h 06m
$215
Quickest round-trip
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Sun 9/13
8:45 pm-10:00 pm
Nonstop2h 15m
Denver Intl
Sat 9/19
7:35 am-10:35 am
Nonstop2h 00m
$286
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Tue 9/22
4:40 pm-6:10 pm
Nonstop2h 30m
Denver Intl
Wed 9/23
2:50 pm-10:59 pm
1 stop7h 09m
$295
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Tue 9/22
5:10 am-6:43 am
Nonstop2h 33m
Denver Intl
Mon 9/28
8:28 pm-11:44 pm
Nonstop2h 16m
$339
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Thu 11/26
1:39 pm-3:09 pm
Nonstop2h 30m
Denver Intl
Mon 11/30
5:33 pm-8:34 pm
Nonstop2h 01m
$340
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Fri 7/31
7:10 pm-11:00 pm
1 stop4h 50m
Denver Intl
Tue 8/4
11:15 am-5:55 pm
2 stops5h 40m
$365
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Sun 8/23
9:00 am-10:31 am
Nonstop2h 31m
Denver Intl
Tue 8/25
1:27 pm-4:34 pm
Nonstop2h 07m
$366
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Fri 7/24
10:35 pm-11:55 pm
Nonstop2h 20m
Denver Intl
Sun 7/26
8:45 pm-11:55 pm
Nonstop2h 10m
$367
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Wed 7/22
2:10 pm-5:00 pm
1 stop3h 50m
Denver Intl
Sat 7/25
10:10 am-6:00 pm
2 stops6h 50m
$380
Showing 1-10 of 20 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 June.
| 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*1 star | |
| Price Accuracy2 stars | Trust Score*3 stars | |
| 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
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Airlines
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 $173). Flying from St. Louis to Denver in June is currently the most expensive (average of $342). 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 June 28, 2026.
It’s optimal to fly from St. Louis to Denver in the evening. By choosing this option you can save up to 52% 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 June 27, 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 June 28, 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.
Comfort
8.0
Overall
7.9
Food
7.0
Entertainment
7.5
Boarding
8.1
Crew
8.6
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Overall
7.9
Food
7.0
Entertainment
7.5
Boarding
8.1
Crew
8.6
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Overall
7.9
Food
7.0
Entertainment
7.5
Boarding
8.1
Crew
8.6
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Overall
7.9
Food
7.0
Entertainment
7.5
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
Black Hawk
Westminster
Centennial
Lakewood
Broomfield
Golden
Greeley
Lone Tree
Wheat Ridge
Silverthorne
Central City
Fort Morgan
Cripple Creek
Winter Park
Manitou Springs
Frisco
Englewood
Glendale
Evergreen
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St. Louis and Denver flights
Browse other St. Louis and Denver flight options. Last updated on June 28, 2026.
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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 June 28, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$56 | Average$149 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$166 | Average$332 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$167 | Average$331 | FlexibilityNo cancel fee | On-time69% |