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

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Low fares from St. Louis to Philadelphia

$

St. Louis (STL)to

Philadelphia (PHL)
Depart: 10/03/2026

One-way

Basic

From
$129
Seen: 23 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 09/10/2026

One-way

Basic

From
$129
Seen: 18 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 10/13/2026

One-way

Basic

From
$129
Seen: 8 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 09/14/2026

One-way

Basic

From
$129
Seen: 11 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 11/09/2026

One-way

Basic

From
$129
Seen: 9 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 10/19/2026

One-way

Basic

From
$129
Seen: 10 hrs ago

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Explore flights from St. Louis to Philadelphia

Aug 2026
From$284*
Seen: 11 hrs ago
One Way/Basic
Sep 2026
From$129*
Seen: 20 hrs ago
One Way/Basic
Oct 2026
From$129*
Seen: 1 hour ago
One Way/Basic
cmp-daily-histogram-bars-legend-min-price-aria-label $129
cmp-daily-histogram-bars-legend-max-price-aria-label $327
Displaying fares for August-2026
  • STL–PHL, 08/22/2026: From $284
    22

    Sat

    AUG

  • STL–PHL, 08/23/2026: From $327
    23

    Sun

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

    Mon

  • STL–PHL, 08/25/2026: From $284
    25

    Tue

  • STL–PHL, 08/26/2026: From $284
    26

    Wed

  • STL–PHL, 08/27/2026: From $319
    27

    Thu

  • STL–PHL: cmp-view-offers-disclaimer. Find Offers
    28

    Fri

  • STL–PHL, 08/29/2026: From $284
    29

    Sat

  • STL–PHL, 08/30/2026: From $319
    30

    Sun

  • STL–PHL, 08/31/2026: From $319
    31

    Mon

  • STL–PHL, 09/01/2026: From $284
    01

    Tue

    SEP

  • STL–PHL, 09/02/2026: From $284
    02

    Wed

  • STL–PHL, 09/03/2026: From $319
    03

    Thu

  • STL–PHL, 09/04/2026: From $301
    04

    Fri

  • STL–PHL, 09/05/2026: From $220
    05

    Sat

  • STL–PHL, 09/06/2026: From $220
    06

    Sun

  • STL–PHL, 09/07/2026: From $301
    07

    Mon

  • STL–PHL, 09/08/2026: From $284
    08

    Tue

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

    Wed

  • STL–PHL, 09/10/2026: From $129
    10

    Thu

  • STL–PHL, 09/11/2026: From $140
    11

    Fri

  • STL–PHL: cmp-view-offers-disclaimer. Find Offers
    12

    Sat

  • STL–PHL, 09/13/2026: From $204
    13

    Sun

  • STL–PHL, 09/14/2026: From $129
    14

    Mon

  • STL–PHL, 09/15/2026: From $129
    15

    Tue

  • STL–PHL, 09/16/2026: From $129
    16

    Wed

  • STL–PHL, 09/17/2026: From $154
    17

    Thu

  • STL–PHL, 09/18/2026: From $140
    18

    Fri

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

    Sat

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

    Sun

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

    Mon

    • Range$129-$327

    *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:
    Lambert-St Louis Int'l Airport
    Arriving at:
    Philadelphia International Airport
    Average flight time:
    2 hours 7 minutes
    Distance:
    814 miles

    Route Information

    141† 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 St. Louis to Philadelphia is 2 hours 7 minutes.
    There are 141 weekly flights from St. Louis to Philadelphia on Southwest Airlines.
    Yes, Southwest flies nonstop from St. Louis to Philadelphia 2 times per day from Monday through Friday.
    Yes, Southwest flies nonstop from St. Louis to Philadelphia once per day on Saturdays and 3 times per day on Sundays.
    To find the lowest fares by day and time to fly St. Louis to Philadelphia with Southwest, check out our Low Fare Calendar.
    You can rent a car at Philadelphia International Airport book yours with your flight.
    Yes! Flights from St. Louis to Philadelphia—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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