Southwest® flights from Seattle/Tacoma to St. Louis from $109

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Low fares from Seattle/Tacoma to St. Louis

$

Seattle/Tacoma (SEA)to

St. Louis (STL)
Depart: 12/12/2026

One-way

Basic

From
$104
Seen: 4 hrs ago

Seattle/Tacoma (SEA)to

St. Louis (STL)
Depart: 11/11/2026

One-way

Basic

From
$109
Seen: 5 hrs ago

Seattle/Tacoma (SEA)to

St. Louis (STL)
Depart: 10/31/2026

One-way

Basic

From
$109
Seen: 3 hrs ago

Seattle/Tacoma (SEA)to

St. Louis (STL)
Depart: 11/02/2026

One-way

Basic

From
$114
Seen: 13 hrs ago

Seattle/Tacoma (SEA)to

St. Louis (STL)
Depart: 10/30/2026

One-way

Basic

From
$114
Seen: 17 hrs ago

Seattle/Tacoma (SEA)to

St. Louis (STL)
Depart: 10/29/2026

One-way

Basic

From
$114
Seen: 4 hrs ago

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Explore flights from Seattle/Tacoma to St. Louis

Sep 2026
From$251*
Seen: 17 hrs ago
One Way/Basic
Oct 2026
From$109*
Seen: 3 hrs ago
One Way/Basic
Nov 2026
From$109*
Seen: 5 hrs ago
One Way/Basic
cmp-daily-histogram-bars-legend-min-price-aria-label $219
cmp-daily-histogram-bars-legend-max-price-aria-label $307
Displaying fares for September-2026
  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    11

    Fri

    SEP

  • SEA–STL, 09/12/2026: From $251
    12

    Sat

  • SEA–STL, 09/13/2026: From $258
    13

    Sun

  • SEA–STL, 09/14/2026: From $307
    14

    Mon

  • SEA–STL, 09/15/2026: From $271
    15

    Tue

  • SEA–STL, 09/16/2026: From $261
    16

    Wed

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    17

    Thu

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    18

    Fri

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    19

    Sat

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    20

    Sun

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    21

    Mon

  • SEA–STL, 09/22/2026: From $261
    22

    Tue

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    23

    Wed

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    24

    Thu

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    25

    Fri

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    26

    Sat

  • SEA–STL, 09/27/2026: From $279
    27

    Sun

  • SEA–STL, 09/28/2026: From $279
    28

    Mon

  • SEA–STL, 09/29/2026: From $261
    29

    Tue

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    30

    Wed

  • SEA–STL, 10/01/2026: From $289
    01

    Thu

    OCT

  • SEA–STL, 10/02/2026: From $234
    02

    Fri

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    03

    Sat

  • SEA–STL, 10/04/2026: From $279
    04

    Sun

  • SEA–STL, 10/05/2026: From $224
    05

    Mon

  • SEA–STL, 10/06/2026: From $234
    06

    Tue

  • SEA–STL, 10/07/2026: From $219
    07

    Wed

  • SEA–STL, 10/08/2026: From $260
    08

    Thu

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    09

    Fri

  • SEA–STL: cmp-view-offers-disclaimer. Find Offers
    10

    Sat

    • Range$219-$307

    *Fares displayed have been collected within the last 24 hours and may no longer be available at time of booking. Additional fees and charges for optional products and services may apply. Modifying this information may result in a different fare. To find the most updated fare, please visit Southwest.com. Fares listed are Basic, which are subject to additional terms and conditions.

    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.

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