Southwest® flights from St. Louis to Philadelphia from $139

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Low fares from St. Louis to Philadelphia

$

St. Louis (STL)to

Philadelphia (PHL)
Depart: 10/30/2026

One-way

Basic

From
$139
Seen: 21 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 09/05/2026

One-way

Basic

From
$139
Seen: 19 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 09/14/2026

One-way

Basic

From
$155
Seen: 22 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 08/31/2026

One-way

Basic

From
$155
Seen: 20 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 10/19/2026

One-way

Basic

From
$155
Seen: 14 hrs ago

St. Louis (STL)to

Philadelphia (PHL)
Depart: 08/26/2026

One-way

Basic

From
$155
Seen: 15 hrs ago

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Explore flights from St. Louis to Philadelphia

Aug 2026
From$155*
Seen: 21 hrs ago
One Way/Basic
Sep 2026
From$139*
Seen: 19 hrs ago
One Way/Basic
Oct 2026
From$139*
Seen: 21 hrs ago
One Way/Basic
cmp-daily-histogram-bars-legend-min-price-aria-label $155
cmp-daily-histogram-bars-legend-max-price-aria-label $319
Displaying fares for August-2026
  • STL–PHL, 08/02/2026: From $319
    02

    Sun

    AUG

  • STL–PHL, 08/03/2026: From $319
    03

    Mon

  • STL–PHL, 08/04/2026: From $284
    04

    Tue

  • STL–PHL, 08/05/2026: From $284
    05

    Wed

  • STL–PHL, 08/06/2026: From $319
    06

    Thu

  • STL–PHL, 08/07/2026: From $319
    07

    Fri

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

    Sat

  • STL–PHL, 08/09/2026: From $319
    09

    Sun

  • STL–PHL, 08/10/2026: From $319
    10

    Mon

  • STL–PHL, 08/11/2026: From $284
    11

    Tue

  • STL–PHL, 08/12/2026: From $284
    12

    Wed

  • STL–PHL, 08/13/2026: From $319
    13

    Thu

  • STL–PHL, 08/14/2026: From $319
    14

    Fri

  • STL–PHL, 08/15/2026: From $284
    15

    Sat

  • STL–PHL, 08/16/2026: From $301
    16

    Sun

  • STL–PHL, 08/17/2026: From $301
    17

    Mon

  • STL–PHL, 08/18/2026: From $284
    18

    Tue

  • STL–PHL, 08/19/2026: From $284
    19

    Wed

  • STL–PHL, 08/20/2026: From $301
    20

    Thu

  • STL–PHL, 08/21/2026: From $301
    21

    Fri

  • STL–PHL, 08/22/2026: From $155
    22

    Sat

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

    Sun

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

    Mon

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

    Tue

  • STL–PHL, 08/26/2026: From $155
    26

    Wed

  • STL–PHL, 08/27/2026: From $165
    27

    Thu

  • STL–PHL, 08/28/2026: From $169
    28

    Fri

  • STL–PHL, 08/29/2026: From $155
    29

    Sat

  • STL–PHL, 08/30/2026: From $199
    30

    Sun

  • STL–PHL, 08/31/2026: From $155
    31

    Mon

  • STL–PHL: cmp-view-offers-disclaimer. Find Offers
    01

    Tue

    SEP

    • Range$155-$319

    *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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