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

Promo Code

Low fares from St. Louis to Phoenix

$

St. Louis (STL)to

Phoenix (PHX)
Depart: 09/29/2026

One-way

Basic

From
$139
Seen: 8 hrs ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 10/17/2026

One-way

Basic

From
$139
Seen: 7 hrs ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 10/10/2026

One-way

Basic

From
$139
Seen: 5 hrs ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 09/23/2026

One-way

Basic

From
$139
Seen: 5 hrs ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 09/26/2026

One-way

Basic

From
$139
Seen: 2 hrs ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 11/07/2026

One-way

Basic

From
$139
Seen: 4 hrs ago

Looking for more low-fare flights?

Check out the Low Fare Calendar to find a fare that works for you. Just choose the month you want to depart and return, and we’ll show you the best fares available.

Find low fares

Explore flights from St. Louis to Phoenix

Aug 2026
From$139*
Seen: 5 hrs ago
One Way/Basic
Sep 2026
From$139*
Seen: 9 hrs ago
One Way/Basic
Oct 2026
From$139*
Seen: 18 hrs ago
One Way/Basic
cmp-daily-histogram-bars-legend-min-price-aria-label $139
cmp-daily-histogram-bars-legend-max-price-aria-label $327
Displaying fares for August-2026
  • STL–PHX, 08/02/2026: From $327
    02

    Sun

    AUG

  • STL–PHX, 08/03/2026: From $327
    03

    Mon

  • STL–PHX, 08/04/2026: From $281
    04

    Tue

  • STL–PHX, 08/05/2026: From $281
    05

    Wed

  • STL–PHX, 08/06/2026: From $327
    06

    Thu

  • STL–PHX, 08/07/2026: From $327
    07

    Fri

  • STL–PHX, 08/08/2026: From $281
    08

    Sat

  • STL–PHX, 08/09/2026: From $327
    09

    Sun

  • STL–PHX, 08/10/2026: From $327
    10

    Mon

  • STL–PHX, 08/11/2026: From $281
    11

    Tue

  • STL–PHX, 08/12/2026: From $281
    12

    Wed

  • STL–PHX, 08/13/2026: From $327
    13

    Thu

  • STL–PHX, 08/14/2026: From $327
    14

    Fri

  • STL–PHX, 08/15/2026: From $281
    15

    Sat

  • STL–PHX, 08/16/2026: From $315
    16

    Sun

  • STL–PHX, 08/17/2026: From $315
    17

    Mon

  • STL–PHX, 08/18/2026: From $281
    18

    Tue

  • STL–PHX, 08/19/2026: From $281
    19

    Wed

  • STL–PHX, 08/20/2026: From $315
    20

    Thu

  • STL–PHX, 08/21/2026: From $315
    21

    Fri

  • STL–PHX, 08/22/2026: From $281
    22

    Sat

  • STL–PHX, 08/23/2026: From $265
    23

    Sun

  • STL–PHX, 08/24/2026: From $202
    24

    Mon

  • STL–PHX, 08/25/2026: From $202
    25

    Tue

  • STL–PHX, 08/26/2026: From $139
    26

    Wed

  • STL–PHX, 08/27/2026: From $149
    27

    Thu

  • STL–PHX, 08/28/2026: From $199
    28

    Fri

  • STL–PHX, 08/29/2026: From $139
    29

    Sat

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

    Sun

  • STL–PHX, 08/31/2026: From $149
    31

    Mon

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

    Tue

    SEP

    • Range$139-$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:
    Sky Harbor International Airport
    Average flight time:
    3 hours 19 minutes
    Distance:
    1262 miles

    Route Information

    156† Weekly flights
    • 4‡ Nonstop flights per day Monday through Friday
    • 4‡ Nonstop flights on Saturday
    • 4‡ 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 Phoenix is 3 hours 19 minutes.
    There are 156 weekly flights from St. Louis to Phoenix on Southwest Airlines.
    Yes, Southwest flies nonstop from St. Louis to Phoenix 4 times per day from Monday through Friday.
    Yes, Southwest flies nonstop from St. Louis to Phoenix 4 times per day on Saturdays and Sundays.
    To find the lowest fares by day and time to fly St. Louis to Phoenix with Southwest, check out our Low Fare Calendar.
    You can rent a car at Sky Harbor International Airport book yours with your flight.
    Yes! Flights from St. Louis to Phoenix—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.

    Explore Flights from Other Popular Origins

    Popular Flights from St. Louis