$33 Cheap flight deals from Denver (DEN) to O'Fallon (STL)

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This Weekend's Flight Deals from Denver to O'Fallon

This weekend's flight prices found within the past 7 days, for the period specified. Prices and availability are subject to change. Additional terms apply.

Sun, Aug 16 - Mon, Aug 24
DEN
Denver Intl.
STL
Lambert-St. Louis Intl.
$320 Roundtrip, found 1 day ago
$320
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Sun, Aug 16 from Denver Intl. to Lambert-St. Louis Intl., returning Mon, Aug 24, priced at $320 found 1 day ago

Airfares from $33 One Way, $76 Round Trip from Denver to O'Fallon

Prices starting at $76 for return flights and $33 for one-way flights to O'Fallon were the cheapest prices found within the past 7 days, for the period specified. Prices and availability are subject to change. Additional terms apply.

Fri, Oct 30 - Sun, Nov 1
DEN
Denver
STL
St. Louis
$76 Roundtrip, found 9 hours ago
$76
Roundtrip
found 9 hours ago
Select Frontier Airlines flight, departing Fri, Oct 30 from Denver to St. Louis, returning Sun, Nov 1, priced at $76 found 9 hours ago
Fri, Sep 11 - Wed, Sep 16
DEN
Denver
STL
St. Louis
$78 Roundtrip, found 8 hours ago
$78
Roundtrip
found 8 hours ago
Select Frontier Airlines flight, departing Fri, Sep 11 from Denver to St. Louis, returning Wed, Sep 16, priced at $78 found 8 hours ago
Wed, Oct 14 - Tue, Oct 20
DEN
Denver
STL
St. Louis
$88 Roundtrip, found 8 hours ago
$88
Roundtrip
found 8 hours ago
Select Frontier Airlines flight, departing Wed, Oct 14 from Denver to St. Louis, returning Tue, Oct 20, priced at $88 found 8 hours ago
Fri, Oct 9 - Tue, Oct 20
DEN
Denver
STL
St. Louis
$90 Roundtrip, found 4 hours ago
$90
Roundtrip
found 4 hours ago
Select Frontier Airlines flight, departing Fri, Oct 9 from Denver to St. Louis, returning Tue, Oct 20, priced at $90 found 4 hours ago
Wed, Sep 9 - Wed, Sep 16
DEN
Denver
STL
St. Louis
$207 Roundtrip, found 6 hours ago
$207
Roundtrip
found 6 hours ago
Select United flight, departing Wed, Sep 9 from Denver to St. Louis, returning Wed, Sep 16, priced at $207 found 6 hours ago

O'Fallon economy flight packages

Price found within the past 48 hours. Click for updated prices.
The Wildwood Hotel
3.5-star property

The Wildwood Hotel

9.2/10 Wonderful! (1,672 reviews)

Oct 1 - Oct 4

3 night stay

Denver (DEN) to St. Louis (STL)

Southwest Airlines • Coach

St. Louis (STL) to Denver (DEN)

Frontier Airlines • Coach
Save 100% on your flight
Price was $804, price is now $512 per person
$512
per person
found 20 hours ago

The Cheshire
4.0-star property

The Cheshire

8.8/10 Excellent! (1,006 reviews)

Oct 1 - Oct 4

3 night stay

Denver (DEN) to St. Louis (STL)

Southwest Airlines • Coach

St. Louis (STL) to Denver (DEN)

Frontier Airlines • Coach
Price was $736, price is now $558 per person
$558
per person
found 20 hours ago
When checking in, the staff woman was less than friendly. There seemed to be a situation with another upset guest that may have caused the unpleasant nature. Once we entered the room, we noticed right away a musty smell. The AC did not seem to be working correctly. Though it never got hot, it also never got any cooler. The furniture had visible stains and a few of the pillow cases had staining as well. The pillows themselves are downed pillows and once you lay on them, they flatten out thin. We requested a few extra pillows that were supposed to be brought to our room which never arrived. We requested more towels which were also supposed to be brought to our room which also never arrived. Breakfast on morning one for us which was Sunday was great, however it was apparent that the fruit and pastries were being reused daily and by our check out morning on Tuesday they were no good. The pool area was decent. You have to reserve the canopy so it was unusable to us. Overall, our stay was okay. I wouldn’t say it was awful but I wouldn’t say it was great either. We don’t intend on staying in the future.

Reviewed on Aug 9, 2026

The Knight Center at Washington University
2.5-star property

The Knight Center at Washington University

9.4/10 Exceptional! (646 reviews)

Oct 1 - Oct 4

3 night stay

Denver (DEN) to St. Louis (STL)

Southwest Airlines • Coach

St. Louis (STL) to Denver (DEN)

Frontier Airlines • Coach
Price was $645, price is now $546 per person
$546
per person
found 20 hours ago
Very clean rooms, friendly staff, nice thick pillows. My only complaint is that the room temperature can only be adjusted from 70-68 degrees.

Reviewed on Aug 9, 2026

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More About Flying To O'Fallon from Denver

Route Information for Flights from Denver to O'Fallon

Origin Airport IATA Code
DEN
Destination Airport IATA Code
STL
Distance
Direct Flight Airlines
Earliest Flight Arrival
Latest Flight Arrival

Denver to O'Fallon

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Fare, taxes & fees: Fares include all taxes and fees, except baggage fees. Rates shown reflect fares found by other Orbitz users over the past 7 days. Due to rapidly changing airline prices & seat availability, these fares may no longer be available.

Refunds/changes/cancellations: Itinerary changes, if permitted for the fare, will have a $30 service fee charged by Orbitz. Additional airline charges may apply.

Other conditions: Schedules, fares and rules are subject to change without notice. Seats are limited and may not be available on all flights/dates or in all markets. Lower fares may be available. Fares will not be honored retroactively or in exchange for any wholly/partially unused ticket. Tickets are non-transferable and non-refundable. Fare rules are provided for the selected itinerary before booking.