Earn point on your loyalty program!arrow arc left

Cheap flights from St Louis (STL) to Denver (DEN)

Know your dates, get live prices in seconds
airplane logo

pin logo

calendar
Departure
calendar backward
Return
airplane logo
1 Adults (11+)
0 Children (2~11)
0 Infants (0~2)
Save up to 31%
Book Flight + Hotel at the same time

How to find the cheapest flight from St Louis (STL) to Denver (DEN)

How to find the cheapest flight from St Louis (STL) to Denver (DEN)
Some placeholder content for the first accordion panel. This panel is shown by default, thanks to the .show class.
How to find the cheapest flight from St Louis (STL) to Denver (DEN)
Some placeholder content for the first accordion panel. This panel is shown by default, thanks to the .show class.
How to find the cheapest flight from St Louis (STL) to Denver (DEN)
Some placeholder content for the first accordion panel. This panel is shown by default, thanks to the .show class.

Cheap flights from St Louis to Denver in September , October 2026

30 Sep - 28 Oct $ 92.00
STL
St Louis
Frontier Airlines
DIRECT
DEN
Denver
DEN
Denver
Frontier Airlines
DIRECT
STL
St Louis
Pick dates
16 Sep - 07 Oct $ 203.00
STL
St Louis
Frontier Airlines
1 STOPS
DEN
Denver
DEN
Denver
Frontier Airlines
DIRECT
STL
St Louis
Pick dates
13 Sep - 10 Oct $ 487.00
STL
St Louis
Frontier Airlines
DIRECT
DEN
Denver
DEN
Denver
Frontier Airlines
DIRECT
STL
St Louis
Pick dates

Last minute flights from St Louis to Denver

23 Sep - 30 Sep $ 162.00
STL
St Louis
Frontier Airlines
1 STOPS
DEN
Denver
DEN
Denver
Frontier Airlines
DIRECT
STL
St Louis
Pick dates
16 Sep - 30 Sep $ 203.00
STL
St Louis
Frontier Airlines
1 STOPS
DEN
Denver
DEN
Denver
Frontier Airlines
DIRECT
STL
St Louis
Pick dates
13 Sep - 30 Sep $ 397.00
STL
St Louis
Frontier Airlines
DIRECT
DEN
Denver
DEN
Denver
Frontier Airlines
DIRECT
STL
St Louis
Pick dates

One-way flights to Denver from St Louis

8:10 PM - 8:10 PM
Frontier Airlines
0 Stops
2h 29m
STL - DEN
$ 46
Kiwi
Pick dates
2:29 PM - 7:38 PM
Frontier Airlines
1 Stops
7h 34m
STL - DEN
$ 157
Kiwi
Pick dates
1:02 PM - 1:02 PM
Frontier Airlines
0 Stops
2h 24m
STL - DEN
$ 351
Kiwi
Pick dates

How to find the cheapest flight from St Louis (STL) to Denver (DEN)

Related info for your journey
Some placeholder content for the first accordion panel. This panel is shown by default, thanks to the .show class.
How to find the cheapest flight from St Louis (STL) to Denver (DEN)
Some placeholder content for the first accordion panel. This panel is shown by default, thanks to the .show class.
How to find the cheapest flight from St Louis (STL) to Denver (DEN)
Some placeholder content for the first accordion panel. This panel is shown by default, thanks to the .show class.