
Popular airlines from St. Louis to Westport
- Alaska Airlines
Alaska Airlines
- United
United
- American Airlines
American Airlines
- Delta
Delta
- Southwest Airlines
Southwest Airlines
- Frontier Airlines
Frontier Airlines
- Sun Country Airlines
Sun Country Airlines
- Plan, book, fly with confidence
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Cheap Flights from St. Louis to Westport (STL-SEA)
Prices were available within the past 7 days and start at $70 for one-way flights and $145 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Mon, Aug 25 - Thu, Sep 4
STL
St. Louis
SEA
Seattle
$145 Roundtrip, found 4 hours ago
$145
Roundtrip
found 4 hours ago

Mon, Sep 15 - Sat, Sep 20
STL
St. Louis
SEA
Seattle
$147 Roundtrip, found 15 hours ago
$147
Roundtrip
found 15 hours ago

Sun, Aug 31 - Thu, Sep 4
STL
St. Louis
SEA
Seattle
$150 Roundtrip, just found
$150
Roundtrip
just found

Thu, Nov 6 - Tue, Nov 11
STL
St. Louis
SEA
Seattle
$155 Roundtrip, just found
$155
Roundtrip
just found

Sun, Aug 31 - Wed, Sep 10
STL
St. Louis
SEA
Seattle
$243 Roundtrip, found 4 hours ago
$243
Roundtrip
found 4 hours ago

Sun, Aug 31 - Thu, Sep 4
STL
St. Louis
SEA
Seattle
$243 Roundtrip, just found
$243
Roundtrip
just found
Find the cheapest month to fly from St. Louis (STL) to Seattle (SEA)
September is typically the cheapest month to fly
From $138 - $211 per traveler.
Graph displaying average flight prices per month
*Available to One Key members.