Southwest® flights from St. Louis to Phoenix from $128

Promo Code

Low fares from St. Louis to Phoenix

$

St. Louis (STL)to

Phoenix (PHX)
Depart: 04/04/2026

One-way

Basic

From
$128
Seen: 5 hrs ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 04/18/2026

One-way

Basic

From
$128
Seen: 3 hrs ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 03/07/2026

One-way

Basic

From
$128
Seen: 1 hour ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 02/21/2026

One-way

Basic

From
$128
Seen: 5 hrs ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 04/11/2026

One-way

Basic

From
$128
Seen: 3 hrs ago

St. Louis (STL)to

Phoenix (PHX)
Depart: 02/28/2026

One-way

Basic

From
$128
Seen: 3 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

*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