Flights to O'Fallon from Phoenix - $79

View $79 flight on Thu, Aug 21, 2025Opens in a new window

Popular airlines from Phoenix to O'Fallon

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Cheap Flights from Phoenix to O'Fallon (PHX-STL)

Prices were available within the past 7 days and start at $79 for one-way flights and $157 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Spirit Airlines
Wed, Aug 6 - Mon, Aug 11
PHX
Phoenix
STL
St. Louis
$157 Roundtrip, found 3 hours ago
$157
Roundtrip
found 3 hours ago
Select Spirit Airlines flight, departing Wed, Aug 6 from Phoenix to St. Louis, returning Mon, Aug 11, priced at $157 found 3 hours ago
Spirit Airlines
Wed, Jul 16 - Fri, Jul 18
PHX
Phoenix
STL
St. Louis
$158 Roundtrip, found 1 day ago
$158
Roundtrip
found 1 day ago
Select Spirit Airlines flight, departing Wed, Jul 16 from Phoenix to St. Louis, returning Fri, Jul 18, priced at $158 found 1 day ago
Frontier Airlines
Sun, Aug 10 - Wed, Aug 13
PHX
Phoenix
STL
St. Louis
$165 Roundtrip, found 3 days ago
$165
Roundtrip
found 3 days ago
Select Frontier Airlines flight, departing Sun, Aug 10 from Phoenix to St. Louis, returning Wed, Aug 13, priced at $165 found 3 days ago
Southwest Airlines
Wed, Aug 13 - Fri, Aug 15
PHX
Phoenix
STL
St. Louis
$177 Roundtrip, found 2 days ago
$177
Roundtrip
found 2 days ago
Select Southwest Airlines flight, departing Wed, Aug 13 from Phoenix to St. Louis, returning Fri, Aug 15, priced at $177 found 2 days ago
United
Wed, Aug 20 - Fri, Aug 22
PHX
Phoenix
STL
St. Louis
$189 Roundtrip, found 3 days ago
$189
Roundtrip
found 3 days ago
Select United flight, departing Wed, Aug 20 from Phoenix to St. Louis, returning Fri, Aug 22, priced at $189 found 3 days ago
Delta
Wed, Aug 20 - Fri, Aug 22
PHX
Phoenix
STL
St. Louis
$199 Roundtrip, found 3 days ago
$199
Roundtrip
found 3 days ago
Select Delta flight, departing Wed, Aug 20 from Phoenix to St. Louis, returning Fri, Aug 22, priced at $199 found 3 days ago

Find the cheapest month to fly from Phoenix (PHX) to St. Louis (STL)

September is typically the cheapest month to fly

From $118 - $365 per traveler.

Graph displaying average flight prices per month

Alternative airports near O'Fallon

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Lambert-St. Louis Intl. STL. Cheapest option available. Average driving time to city center is 36 minutes. Flights from $233
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center36 min
Flights from $233
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