Flights from St. Louis, MO to Denver, CO

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Best Deals on Flights From St. Louis, MO (STL) to Denver, CO (DEN)

Try alternate month or interact with individual days below in order to find offers.
Apr 2026
No results for this month.
May 2026
from$19*
Last seen: 12 hours ago
One-way/Economy
Jun 2026
from$19*
Last seen: 16 hours ago
One-way/Economy
$19
$168
Displaying fares for April-2026
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    • Range$19-$168

    *Prices found by others in the previous 48 hours for round-trip flights. Prices shown may also require membership in our travel club, Discount Den.

    Flights Deals from St. Louis, MO to Denver, CO on Frontier

    $
    Flights Deals from St. Louis, MO to Denver, CO on Frontier
    From
    To
    St. Louis, MO (STL)Denver, CO (DEN)One-way
    /
    Discount Den Basic Fare    		Departing Aug 19, 2026

    From

    $19

    Last seen: 1 hour ago

    *Prices found by others in the previous 48 hours for one-way flights. Prices shown may also require membership in our travel club, Discount Den®.

    St. Louis, MO Denver, CO

    Barclays Badge

    Earn 50,000 Miles after qualifying activity. Plus $0 Intro Annual Fee, then $99.
    Terms Apply.