Southwest® flights from Philadelphia to St. Louis from $129

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Low fares from Philadelphia to St. Louis

$

Philadelphia (PHL)to

St. Louis (STL)
Depart: 12/17/2026

One-way

Basic

From
$129
Seen: 19 hrs ago

Philadelphia (PHL)to

St. Louis (STL)
Depart: 10/06/2026

One-way

Basic

From
$129
Seen: 22 hrs ago

Philadelphia (PHL)to

St. Louis (STL)
Depart: 10/27/2026

One-way

Basic

From
$129
Seen: 15 hrs ago

Philadelphia (PHL)to

St. Louis (STL)
Depart: 11/16/2026

One-way

Basic

From
$129
Seen: 10 hrs ago

Philadelphia (PHL)to

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

One-way

Basic

From
$129
Seen: 8 hrs ago

Philadelphia (PHL)to

St. Louis (STL)
Depart: 11/12/2026

One-way

Basic

From
$129
Seen: 20 hrs ago

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Explore flights from Philadelphia to St. Louis

Sep 2026
From$294*
Seen: 3 hrs ago
One Way/Basic
Oct 2026
From$129*
Seen: 17 hrs ago
One Way/Basic
Nov 2026
From$129*
Seen: 21 hrs ago
One Way/Basic
cmp-daily-histogram-bars-legend-min-price-aria-label $129
cmp-daily-histogram-bars-legend-max-price-aria-label $330
Displaying fares for September-2026
  • PHL–STL: cmp-view-offers-disclaimer. Find Offers
    10

    Thu

    SEP

  • PHL–STL, 09/11/2026: From $329
    11

    Fri

  • PHL–STL, 09/12/2026: From $294
    12

    Sat

  • PHL–STL: cmp-view-offers-disclaimer. Find Offers
    13

    Sun

  • PHL–STL, 09/14/2026: From $329
    14

    Mon

  • PHL–STL, 09/15/2026: From $294
    15

    Tue

  • PHL–STL, 09/16/2026: From $294
    16

    Wed

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

    Thu

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

    Fri

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

    Sat

  • PHL–STL, 09/20/2026: From $329
    20

    Sun

  • PHL–STL, 09/21/2026: From $329
    21

    Mon

  • PHL–STL: cmp-view-offers-disclaimer. Find Offers
    22

    Tue

  • PHL–STL, 09/23/2026: From $294
    23

    Wed

  • PHL–STL, 09/24/2026: From $311
    24

    Thu

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

    Fri

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

    Sat

  • PHL–STL: cmp-view-offers-disclaimer. Find Offers
    27

    Sun

  • PHL–STL, 09/28/2026: From $330
    28

    Mon

  • PHL–STL, 09/29/2026: From $294
    29

    Tue

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

    Wed

  • PHL–STL, 10/01/2026: From $194
    01

    Thu

    OCT

  • PHL–STL, 10/02/2026: From $150
    02

    Fri

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

    Sat

  • PHL–STL, 10/04/2026: From $214
    04

    Sun

  • PHL–STL: cmp-view-offers-disclaimer. Find Offers
    05

    Mon

  • PHL–STL, 10/06/2026: From $129
    06

    Tue

  • PHL–STL: cmp-view-offers-disclaimer. Find Offers
    07

    Wed

  • PHL–STL, 10/08/2026: From $150
    08

    Thu

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

    Fri

    • Range$129-$330

    *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:
    Philadelphia International Airport
    Arriving at:
    Lambert-St Louis Int'l Airport
    Average flight time:
    2 hours 27 minutes
    Distance:
    814 miles

    Route Information

    147† Weekly flights
    • 2‡ Nonstop flights per day Monday through Friday
    • 1‡ Nonstop flight on Saturday
    • 3‡ Nonstop flights on Sunday

    † 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

    The average flight time from Philadelphia to St. Louis is 2 hours 27 minutes.
    There are 147 weekly flights from Philadelphia to St. Louis on Southwest Airlines.
    Yes, Southwest flies nonstop from Philadelphia to St. Louis 2 times per day from Monday through Friday.
    Yes, Southwest flies nonstop from Philadelphia to St. Louis once per day on Saturdays and 3 times per day on Sundays.
    To find the lowest fares by day and time to fly Philadelphia 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 Philadelphia 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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