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Find low faresSouthwest® flights from Seattle/Tacoma to St. Louis from $89
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1 Passenger
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Low fares from Seattle/Tacoma to St. Louis
$
Seattle/Tacoma (SEA)to
St. Louis (STL)
Depart: 04/23/2026
One-way
Basic
From
$89
Seen: 7 hrs ago
Seattle/Tacoma (SEA)to
St. Louis (STL)
Depart: 02/25/2026
One-way
Basic
From
$105
Seen: 14 hrs ago
Seattle/Tacoma (SEA)to
St. Louis (STL)
Depart: 04/28/2026
One-way
Basic
From
$124
Seen: 22 hrs ago
Seattle/Tacoma (SEA)to
St. Louis (STL)
Depart: 04/23/2026
One-way
Choice
From
$129
Seen: 7 hrs ago
Seattle/Tacoma (SEA)to
St. Louis (STL)
Depart: 04/18/2026
One-way
Basic
From
$140
Seen: 16 hrs ago
Seattle/Tacoma (SEA)to
St. Louis (STL)
Depart: 02/25/2026
One-way
Choice
From
$145
Seen: 14 hrs ago
Explore flights from Seattle/Tacoma to St. Louis
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Flight Details
Departing from:
Seattle/Tacoma International Airport
Arriving at:
Lambert-St Louis Int'l Airport
Distance:
1709 miles
Route Information
145† Weekly flights
† Weekly flights based on DOT published scheduled average flights Monday through Sunday between 9/1/2025 and 9/30/2025. Note: route may not operate every day of the week.
‡ Nonstop flights based on DOT published scheduled average flights Monday through Sunday between 9/1/2025 and 9/30/2025.
Questions we hear the most
There are 145 weekly flights from Seattle/Tacoma to St. Louis on Southwest Airlines.
To find the lowest fares by day and time to fly Seattle/Tacoma to St. Louis with Southwest, check out our Low Fare Calendar.
You can rent a car at Lambert-St Louis Int'l Airport book yours with your flight.
Yes! Flights from Seattle/Tacoma to St. Louis—or from here or there to anywhere—can be changed with no change fees. Fare difference may apply.
Check the status of your upcoming Southwest flight.
Check out the Southwest Airlines® Help Center for answers about everything Southwest.