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$56+ Cheap flights from St. Louis (STL) to Phoenix

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/11. Fares are subject to change and may not be available on all flights or dates of travel.
STL — PHX
Aug 5 — Aug 121
Tue 8/5
Tue 8/12
1 adult, Economy
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Cheapflights Tip: The best prices from Lambert-St Louis to Phoenix are usually found in August or September, booked 76 days in advance, depart on a Wednesday or Tuesday and return on a Tuesday

Cheap flight deals from St. Louis to Phoenix

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Phoenix (PH1). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated July 31, 2025.

Round-trip from

$211
(American Airlines)

One-way from

$56
(Booking.com)

Popular in

March

Cheapest in

August

Average price

$341
From Lambert-St Louis to Phoenix
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One-way flight from Lambert-St Louis to Phoenix
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Highest demand for flights based on searches. 11% potential increase in price ($48 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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Find flight deals from St. Louis to Phoenix

Cheapest flights from St. Louis to Phoenix
Explore the most affordable flight options available from St. Louis to Phoenix. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/172:30 pmSTL - PHX
1 stop9h 07mSpirit Airlines
Sun 8/2410:42 pmPHX - STL
1 stop12h 50mSpirit Airlines
Deal found 7/29$209
This American Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/267:53 amSTL - PHX
Nonstop3h 15mAmerican Airlines
Mon 9/17:11 pmPHX - STL
Nonstop3h 05mAmerican Airlines
Deal found 7/31$211
This CheapOair deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1112:05 pmSTL - PHX
1 stop11h 59mMultiple Airlines
Tue 9/2312:47 pmPHX - STL
1 stop18h 19mMultiple Airlines
Deal found 7/29$214
This Southwest deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/2710:20 amSTL - PHX
1 stop6h 00mSouthwest
Wed 9/35:40 pmPHX - STL
Nonstop2h 55mSouthwest
Deal found 7/30$221
This Justfly.com deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/71:54 pmSTL - PHX
Nonstop3h 22mFrontier
Mon 11/108:00 amPHX - STL
Nonstop2h 59mFrontier
Deal found 7/29$224
This Delta deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/284:45 pmSTL - PHX
1 stop8h 19mDelta
Fri 10/3112:40 amPHX - STL
1 stop6h 11mDelta
Deal found 7/31$237

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Phoenix that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated July 31, 2025.
Use the filters below to find and compare flights from St. Louis to Phoenix that are best for you.

Fly from

St. Louis

Fly to

Phoenix

Route

Depart

Return

Price

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Sun 8/17

2:30 pm-9:37 pm

1 stop9h 07m

Phoenix Sky Harbor Intl

Sun 8/24

10:42 pm-1:32 pm

1 stop12h 50m

$209

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Tue 8/26

7:53 am-9:08 am

Nonstop3h 15m

Phoenix Sky Harbor Intl

Mon 9/1

7:11 pm-12:16 am

Nonstop3h 05m

$211

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Thu 9/11

12:05 pm-10:04 pm

1 stop11h 59m

Phoenix Sky Harbor Intl

Tue 9/23

12:47 pm-9:06 am

1 stop18h 19m

$214

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Wed 8/27

10:20 am-2:20 pm

1 stop6h 00m

Phoenix Sky Harbor Intl

Wed 9/3

5:40 pm-10:35 pm

Nonstop2h 55m

$221

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Tue 10/28

4:45 pm-11:04 pm

1 stop8h 19m

Phoenix Sky Harbor Intl

Fri 10/31

12:40 am-8:51 am

1 stop6h 11m

$237

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Sun 10/12

2:19 pm-10:00 pm

1 stop9h 41m

Phoenix Sky Harbor Intl

Mon 10/20

8:00 am-12:59 pm

Nonstop2h 59m

$252

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Thu 9/11

12:05 pm-10:04 pm

1 stop11h 59m

$56

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Tue 9/30

9:35 am-10:50 am

Nonstop3h 15m

$81

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Fri 10/10

2:54 pm-4:16 pm

Nonstop3h 22m

$99

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Fri 8/22

2:30 pm-11:20 pm

1 stop10h 50m

$103

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/29

Showing 1-10 of 15 results
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Best time to book a flight from St. Louis to Phoenix

Have a flexible travel schedule? Discover the best time to fly to Phoenix from St. Louis with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to Phoenix

How far ahead should I book a flight from St. Louis to Phoenix?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Phoenix. Price data was last updated on July 25, 2025.

The best time to book flights from St. Louis to Phoenix is 76 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from St. Louis to Phoenix?

Currently, January is the cheapest month in which you can book a flight from St. Louis to Phoenix (average of $258). Flying from St. Louis to Phoenix in March is currently the most expensive (average of $337). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from STL to PHX?

Find hourly flight availability from St. Louis to Phoenix. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 31, 2025.

When flying from St. Louis to Phoenix, the time of day you fly usually plays a role in the price. Save by searching for a flight at noon, which can drop the price by up to 11% versus a flight in the morning.

What is the cheapest day to fly from St. Louis to Phoenix?

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Phoenix. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their St. Louis to Phoenix flight should consider departing on Wednesday evenings when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Reviews of airlines servicing Phoenix

Get insights into the airlines that provide service to Phoenix. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Phoenix. Reviews last updated July 31, 2025.
Peruse reviews from past customers who have flown with Alaska Airlines, Southwest, and Delta from St. Louis to Phoenix to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Southwest
8.0
Very good
4,246 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Delta
8.0
Very good
7,981 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
United Airlines
7.4
Good
8,900 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Phoenix. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from St. Louis to Phoenix?

    Located just 12.7 mi from the city center, Lambert-St Louis is the airport most travelers will use when flying to Phoenix from St. Louis. Booking flights from Lambert-St Louis (STL) to Phoenix should be relatively easy as there are 5 daily outbound flights to Phoenix from 6 different airlines.

  • What are the cheapest airlines flying from St. Louis to Phoenix round-trip?

    Currently priced at $211, American Airlines will fly you from St. Louis to Phoenix and back. In addition to American Airlines, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Southwest and Spirit Airlines - these airlines can fly you to your destination from $221 and $222, respectively. These flights start at 44% lower than the current average price 3 months from now.

  • What are the cheapest airlines to fly from St. Louis to Phoenix one-way?

    For one-way options, check prices for Spirit Airlines. According to our data, you can fly for as low as $56. Users have also found prices from $81 and $99 on Southwest and Frontier, respectively.

  • What are the most reliable airlines from St. Louis to Phoenix?

    No one likes to see their flight delayed. When booking a flight from St. Louis to Phoenix consider choosing SkyWest Airlines (74%), Southwest (73%) or American Airlines (56%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from St. Louis to Phoenix?

    While on average a flight from St. Louis to Phoenix is generally $309, our data shows the cheapest flight currently is $92. When looking at the most popular route, (Lambert-St Louis - Phoenix Sky Harbor Intl), you can expect to pay $183 for that flight.

  • Can I find deals for flights from St. Louis to Phoenix that include hotel bookings?

    Yes. In addition to deals on St. Louis to Phoenix flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Phoenix?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Phoenix.

  • Can I find deals for business class flights from St. Louis to Phoenix?

    Yes. Cheapflights offers flight deals from St. Louis to Phoenix by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from St. Louis to Phoenix?

    Currently, January is the cheapest month in which you can book a flight from St. Louis to Phoenix (average of $258). Flying from St. Louis to Phoenix in March is currently the most expensive (average of $337). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

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Top 6 airlines flying from St. Louis to Phoenix

Discover the top 6 airlines that operate flights from St. Louis to Phoenix. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated July 31, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$108Average$210FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$154Average$200FlexibilityNo cancel feeOn-time65%
American AirlinesCheapest$205Average$401FlexibilityNo cancel feeOn-time71%
DeltaCheapest$216Average$356FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$263Average$383FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$277Average$437FlexibilityNo cancel feeOn-time63%

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