Flights to Casco Bay Islands from St. Louis - $145

View $145 flight on Tue, Sep 9, 2025Opens in a new window

Popular airlines from St. Louis to Casco Bay Islands

  • American Airlines

    American Airlines

  • Delta

    Delta

  • United

    United

  • Southwest Airlines

    Southwest Airlines

  • Frontier Airlines

    Frontier Airlines

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Cheap Flights from St. Louis to Casco Bay Islands (STL-PWM)

Prices were available within the past 7 days and start at $145 for one-way flights and $238 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Fri, Aug 15 - Sat, Aug 30
STL
St. Louis
PWM
Portland
$238 Roundtrip, found 8 hours ago
$238
Roundtrip
found 8 hours ago
Select Frontier Airlines flight, departing Fri, Aug 15 from St. Louis to Portland, returning Sat, Aug 30, priced at $238 found 8 hours ago
United
Wed, Sep 3 - Sat, Sep 6
STL
St. Louis
PWM
Portland
$285 Roundtrip, found 3 days ago
$285
Roundtrip
found 3 days ago
Select United flight, departing Wed, Sep 3 from St. Louis to Portland, returning Sat, Sep 6, priced at $285 found 3 days ago
United
Sat, Oct 11 - Sat, Oct 18
STL
St. Louis
PWM
Portland
$287 Roundtrip, found 3 days ago
$287
Roundtrip
found 3 days ago
Select United flight, departing Sat, Oct 11 from St. Louis to Portland, returning Sat, Oct 18, priced at $287 found 3 days ago
American Airlines
Sat, Sep 6 - Thu, Sep 11
STL
St. Louis
PWM
Portland
$289 Roundtrip, found 3 days ago
$289
Roundtrip
found 3 days ago
Select American Airlines flight, departing Sat, Sep 6 from St. Louis to Portland, returning Thu, Sep 11, priced at $289 found 3 days ago
Southwest Airlines
Tue, Nov 4 - Sat, Nov 8
STL
St. Louis
PWM
Portland
$290 Roundtrip, found 3 days ago
$290
Roundtrip
found 3 days ago
Select Southwest Airlines flight, departing Tue, Nov 4 from St. Louis to Portland, returning Sat, Nov 8, priced at $290 found 3 days ago
Delta
Sat, Oct 4 - Wed, Oct 8
STL
St. Louis
PWM
Portland
$297 Roundtrip, just found
$297
Roundtrip
just found
Select Delta flight, departing Sat, Oct 4 from St. Louis to Portland, returning Wed, Oct 8, priced at $297 just found

Find the cheapest month to fly from St. Louis (STL) to Portland (PWM)

September is typically the cheapest month to fly

From $197 - $416 per traveler.

Graph displaying average flight prices per month

Alternative airports

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

Select flight to Portland Intl. Jetport PWM. Cheapest option available. Flights from $372
PWM
Portland Intl. Jetport
Cheapest
Flights from $372
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