Flights from St. Louis to Denver

Our cheapest offers for flights from St. Louis to Denver

Here you can compare cheap flights from St. Louis (STL) to Denver (DEN) for one-way or return trips. The following offers were searched for and found on idealo during the last few days. Or start your own flight search to Denver. Prices and availability may change at any time.

Outbound Return Airlines Shop Baggage Price
Best option
St. Louis
Denver
Outbound
10/18/25
direct
F94567
02h 28min
Return
11/17/25
direct
F93302
02h 07min
Frontier Airlines ?
$137
St. Louis
Denver
Outbound
10/18/25
direct
F94567
02h 28min
Return
11/17/25
direct
F93302
02h 07min
Frontier Airlines
$148
St. Louis
Denver
Outbound
09/04/25
direct
F94567
02h 28min
Return
09/28/25
direct
F93302
02h 07min
Frontier Airlines
$152
St. Louis
Denver
Outbound
10/18/25
direct
F94567
02h 28min
Return
11/17/25
direct
F93302
02h 07min
Frontier Airlines
$154
St. Louis
Denver
Outbound
09/04/25
direct
F94567
02h 28min
Return
09/28/25
direct
F93302
02h 07min
Frontier Airlines
$181
St. Louis
Denver
Outbound
09/04/25
direct
F94567
02h 28min
Return
09/28/25
direct
UA1422
02h 06min
Frontier Airlines ?
$226
St. Louis
Denver
Outbound
10/18/25
direct
UA2132
02h 21min
Return
11/17/25
direct
UA1422
02h 00min
United Airlines ?
$232
St. Louis
Denver
Outbound
10/18/25
1 Stopover (DFW)
AA1363, AA0577
06h 45min
Return
11/17/25
1 Stopover (CLT)
AA3299, AA2475
07h 16min
American Airlines ?
$233
St. Louis
Denver
Outbound
10/18/25
direct
UA5979
02h 38min
Return
11/17/25
direct
UA1422
02h 00min
United Airlines ?
$239
St. Louis
Denver
Outbound
07/25/25
direct
F94567
02h 27min
Return
08/17/25
1 Stopover (MCO)
F91734, F91631
22h 49min
Frontier Airlines
$243
Prices based on recent searches, subject to last-minute changes
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Tips and tricks to help you find cheap flights from St. Louis to Denver

Favorite airline: Frontier Airlines
100 % of bookings on this flight route are made with Frontier Airlines, United Airlines and Delta.
Frontier Airlines
55 %
United Airlines
36 %
Delta
9 %
Direct flights are cheaper
Direct flights on this route are $162.00 cheaper on average than flights with a stopover.
non stop flight
1 stop
02h 28min
08h 30min
117 USD
279 USD
The favorite connection is non-stop
Non-stop flights are especially popular on this route. 88 % of travelers will book a direct flight.
Route
bookings
Direct flights
02h 28min, from 117 USD
88 %
1 stopover Detroit Metropolitan Wayne County Airport, MI
08h 30min, from 279 USD
12 %

Important flight information

Flight information: St. Louis - Denver

Roundtrip from 136,68 USD
Flight duration min. 02:20 / max. 11:15
Return flight duration min. 01:50/ max. 07:30
Distance 1237 km
Flights per week 123
Departure airport Airport St. Louis - Lambert International Airport (STL)
Arrival airport Airport Denver International Airport, CO (DEN)
Destination country Flights to United States
Alternative routes to United States
Alternative flights to Denver
Flight destinations with a similar price
Flight destinations with a similar price