$55 Cheap Flights from St. Louis (STL) to Phoenix (PHX)

View $55 flight on Fri, Dec 12, 2025Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Phoenix Sky Harbor Intl. Airport (PHX)

Today's featured flight deals from St. Louis Lambert Intl. Airport (STL) to Phoenix Sky Harbor Intl. Airport (PHX)

Nonstop
Carry-on included
Lower price than typical

Cheap Flights from St. Louis to Phoenix (STL-PHX)

Prices were available within the past 7 days and start at $55 for one-way flights and $106 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Mon, Oct 27 - Mon, Nov 3
STL
St. Louis
PHX
Phoenix
$106 Roundtrip, just found
$106
Roundtrip
just found
Select Frontier Airlines flight, departing Mon, Oct 27 from St. Louis to Phoenix, returning Mon, Nov 3, priced at $106 just found
Frontier Airlines
Mon, Nov 10 - Fri, Nov 14
STL
St. Louis
PHX
Phoenix
$117 Roundtrip, found 2 hours ago
$117
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Mon, Nov 10 from St. Louis to Phoenix, returning Fri, Nov 14, priced at $117 found 2 hours ago
Southwest Airlines
Wed, Nov 12 - Mon, Nov 17
STL
St. Louis
PHX
Phoenix
$120 Roundtrip, found 13 hours ago
$120
Roundtrip
found 13 hours ago
Select Southwest Airlines flight, departing Wed, Nov 12 from St. Louis to Phoenix, returning Mon, Nov 17, priced at $120 found 13 hours ago
Frontier Airlines
Fri, Nov 14 - Mon, Nov 17
STL
St. Louis
PHX
Phoenix
$123 Roundtrip, found 2 hours ago
$123
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Fri, Nov 14 from St. Louis to Phoenix, returning Mon, Nov 17, priced at $123 found 2 hours ago
Frontier Airlines
Fri, Dec 5 - Sat, Dec 6
STL
St. Louis
PHX
Phoenix
$125 Roundtrip, found 1 hour ago
$125
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Fri, Dec 5 from St. Louis to Phoenix, returning Sat, Dec 6, priced at $125 found 1 hour ago
Frontier Airlines
Fri, Oct 24 - Mon, Oct 27
STL
St. Louis
PHX
Phoenix
$129 Roundtrip, found 5 hours ago
$129
Roundtrip
found 5 hours ago
Select Frontier Airlines flight, departing Fri, Oct 24 from St. Louis to Phoenix, returning Mon, Oct 27, priced at $129 found 5 hours ago
Frontier Airlines
Mon, Oct 27 - Mon, Nov 3
STL
St. Louis
PHX
Phoenix
$133 Roundtrip, just found
$133
Roundtrip
just found
Select Frontier Airlines flight, departing Mon, Oct 27 from St. Louis to Phoenix, returning Mon, Nov 3, priced at $133 just found
American Airlines
Sat, Nov 15 - Tue, Nov 18
STL
St. Louis
PHX
Phoenix
$139 Roundtrip, found 2 hours ago
$139
Roundtrip
found 2 hours ago
Select American Airlines flight, departing Sat, Nov 15 from St. Louis to Phoenix, returning Tue, Nov 18, priced at $139 found 2 hours ago
Delta
Fri, Nov 14 - Tue, Nov 18
STL
St. Louis
PHX
Phoenix
$237 Roundtrip, found 14 hours ago
$237
Roundtrip
found 14 hours ago
Select Delta flight, departing Fri, Nov 14 from St. Louis to Phoenix, returning Tue, Nov 18, priced at $237 found 14 hours ago
Alaska Airlines
Mon, Dec 8 - Tue, Dec 9
STL
St. Louis
PHX
Phoenix
$291 Roundtrip, found 1 hour ago
$291
Roundtrip
found 1 hour ago
Select Alaska Airlines flight, departing Mon, Dec 8 from St. Louis to Phoenix, returning Tue, Dec 9, priced at $291 found 1 hour ago

Find the cheapest month to fly from St. Louis (STL) to Phoenix (PHX)

January is typically the cheapest month to fly

From $118 - $340 per traveler.

Alternative airports near Phoenix

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Sky Harbor Intl. PHX. Cheapest and Closest option available. Average driving time to city center is 10 minutes. Flights from $144
PHX
Sky Harbor Intl.
CheapestClosest
Average driving time to city center10 min
Flights from $144
Flights from St. Louis (STL) to Phoenix (PHX)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Sky Harbor Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Hawaiian Airlines, Southwest Airlines, United
Roundtrip price
$106
Distance
1259 mi
Average flight time
1 hour 27 mins

St. Louis to Phoenix Flights

The cheapest times to fly from St. Louis to Phoenix

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from St. Louis to Phoenix are during the month of October. You can find some of the cheapest flights from St. Louis to Phoenix with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from St. Louis to Phoenix

Sunday is one of the best days to book for cheap flights from St. Louis to Phoenix: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from St. Louis to Phoenix

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from St. Louis to Phoenix in 2025. You can also book with separate airlines for your outbound and return journeys, from $55 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap St. Louis to Phoenix flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your St. Louis to Phoenix airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX) cost?
Grab a cheap one-way flight from $55 or cheap return flight from $106 from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight deals on this route.
What is the cheapest month to fly from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX)?
Traveling in October is a great way to save, as it's the cheapest month for flights between STL and PHX. You'll typically find the lowest fares during off-peak months.
Which airlines fly direct from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX)?
When jetting out of Lambert-St. Louis Intl. Airport (STL), you can get on a nonstop flight to Sky Harbor Intl. Airport (PHX) with Southwest Airlines.
What is the cheapest airline that flies from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX)?
The cheapest airline to offer flights between Lambert-St. Louis Intl. Airport (STL) and Sky Harbor Intl. Airport (PHX) can change depending on when you want to travel. American Airlines and Southwest Airlines are just some good options offering well-priced fares. Use Expedia's filters to compare airlines in one place and find the right STL to PHX flight for your budget.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX)?
When jetting out of Lambert-St. Louis Intl. Airport (STL), you'll have your pick from an average of 6 daily nonstop flights to Sky Harbor Intl. Airport (PHX).
What are the most popular departure times for flights from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX)?
Flights between STL and PHX tend to be busiest at 2 PM. For a more relaxed trip and potentially cheaper prices, choose a departure outside the usual busy windows.
What day of the week has the most flights from STL to PHX?
Depart on a Friday if you're after the best choice of flights from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX).
What is the earliest flight from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX)?
Lambert-St. Louis Intl. Airport (STL)'s first flight to Sky Harbor Intl. Airport (PHX) leaves at approximately 6:00AM UTC-6. With a travel time of 3h 40m, you'll touch down at around 8:40AM UTC-7.
How long does it take to fly from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX)?
Flights from STL to PHX have an average travel time of 3 hours and 32 minutes. The total distance between the two airports is 1,250 mi.
What airline has the least delays from STL to PHX?
Consider booking with Frontier Airlines if you'd like to go straight from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX) without any holdups. This carrier has the strongest track record for punctuality, with an on-time score of 100%. Want to get notified of any changes? You can check your flight status using the Expedia App.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX)?
To avoid potential delays on the Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX) route, travel before 3 PM. Flights after this time have a 22% higher chance of cancellation.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for Phoenix from Lambert-St. Louis Intl. Airport (STL)?
If you're on a direct flight from Lambert-St. Louis Intl. Airport (STL) to Phoenix, Sky Harbor Intl. Airport (PHX) is the only airport you can touch down at.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX) last-minute?
Holding off until right before your break to book your flight from STL to PHX generally means paying more. While you might find some last-minute offers, they're not always guaranteed. Be flexible with your itinerary for the best chance of landing a bargain.
Is it cheaper to book a STL to PHX flight and hotel package?
Compared with arranging hotels and flights separately, booking a STL to PHX flight and hotel package with Expedia could result in significant savings. Better yet, having everything in one easy place takes the hassle out of planning your trip. Just pick your flights and choose from our wide range of stays, then customize your trip with extras like tours and car rentals.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Sky Harbor Intl. Airport (PHX)?
If you booked your STL to PHX flight within the last 24 hours, you may be able to modify or cancel it without fees. Depending on the airline and the type of fare you have, additional charges may apply for changes after that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you want more information.

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*Available to One Key members.