$50 Cheap Flights from St. Louis (STL) to Phoenix (PHX)

View $50 flight on Mon, Dec 8, 2025Opens in a new window

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

    notification illustration

    Be in the know

    Get alerts if flight prices drop or rise*
    deals illustration

    Book smarter

    Save up to 30% on select hotels after you book a flight*
    trophy illustration

    Earn twice

    Earn your airline miles on top of our OneKeyCash
    Learn about One Key

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 $50 for one-way flights and $96 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Mon, Dec 8 - Mon, Dec 15
STL
St. Louis
PHX
Phoenix
$96 Roundtrip, found 5 hours ago
$96
Roundtrip
found 5 hours ago
Select Frontier Airlines flight, departing Mon, Dec 8 from St. Louis to Phoenix, returning Mon, Dec 15, priced at $96 found 5 hours ago
Frontier Airlines
Fri, Nov 28 - Fri, Dec 5
STL
St. Louis
PHX
Phoenix
$106 Roundtrip, found 1 hour ago
$106
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Fri, Nov 28 from St. Louis to Phoenix, returning Fri, Dec 5, priced at $106 found 1 hour ago
Frontier Airlines
Mon, Nov 3 - Mon, Nov 10
STL
St. Louis
PHX
Phoenix
$110 Roundtrip, found 2 hours ago
$110
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Mon, Nov 3 from St. Louis to Phoenix, returning Mon, Nov 10, priced at $110 found 2 hours ago
Frontier Airlines
Mon, Nov 10 - Mon, Nov 17
STL
St. Louis
PHX
Phoenix
$115 Roundtrip, found 2 hours ago
$115
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Mon, Nov 10 from St. Louis to Phoenix, returning Mon, Nov 17, priced at $115 found 2 hours ago
Frontier Airlines
Fri, Nov 28 - Sat, Dec 6
STL
St. Louis
PHX
Phoenix
$120 Roundtrip, found 3 hours ago
$120
Roundtrip
found 3 hours ago
Select Frontier Airlines flight, departing Fri, Nov 28 from St. Louis to Phoenix, returning Sat, Dec 6, priced at $120 found 3 hours ago
Southwest Airlines
Wed, Nov 19 - Fri, Nov 28
STL
St. Louis
PHX
Phoenix
$125 Roundtrip, found 1 hour ago
$125
Roundtrip
found 1 hour ago
Select Southwest Airlines flight, departing Wed, Nov 19 from St. Louis to Phoenix, returning Fri, Nov 28, priced at $125 found 1 hour ago
Frontier Airlines
Sat, Dec 6 - Mon, Dec 15
STL
St. Louis
PHX
Phoenix
$125 Roundtrip, found 1 hour ago
$125
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Sat, Dec 6 from St. Louis to Phoenix, returning Mon, Dec 15, priced at $125 found 1 hour ago
American Airlines
Sat, Dec 6 - Wed, Dec 10
STL
St. Louis
PHX
Phoenix
$139 Roundtrip, found 1 hour ago
$139
Roundtrip
found 1 hour ago
Select American Airlines flight, departing Sat, Dec 6 from St. Louis to Phoenix, returning Wed, Dec 10, priced at $139 found 1 hour ago
Delta
Sat, Dec 6 - Wed, Dec 10
STL
St. Louis
PHX
Phoenix
$217 Roundtrip, found 1 hour ago
$217
Roundtrip
found 1 hour ago
Select Delta flight, departing Sat, Dec 6 from St. Louis to Phoenix, returning Wed, Dec 10, priced at $217 found 1 hour ago
Alaska Airlines
Wed, Nov 12 - Fri, Nov 21
STL
St. Louis
PHX
Phoenix
$302 Roundtrip, found 1 hour ago
$302
Roundtrip
found 1 hour ago
Select Alaska Airlines flight, departing Wed, Nov 12 from St. Louis to Phoenix, returning Fri, Nov 21, priced at $302 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 $149
PHX
Sky Harbor Intl.
CheapestClosest
Average driving time to city center10 min
Flights from $149

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 $50 or cheap return flight from $96 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 December 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.

Travel information

Origin airport
Lambert-St. Louis Intl.
Destination airport
Sky Harbor Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Roundtrip price
$96
Distance
1259 mi
Average flight time
1 hour 20 mins

Book with confidence

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 December. 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 $50 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.

 

St. Louis to Phoenix Flights

Explore a world of travel with Expedia

*Available to One Key members.