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$50+ Cheap flights from Sky Harbor Intl (PHX) to St. Louis (STL)

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 10/17. Fares are subject to change and may not be available on all flights or dates of travel.
PHX — STL
Oct 17 — Oct 241
Fri 10/17
Fri 10/24
1 adult, Economy
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Cheapflights Tip: The best prices from Phoenix Sky Harbor Intl to Lambert-St Louis are usually found in August or September, booked 87 days in advance, depart on a Tuesday or Wednesday and return on a Wednesday

Cheap flight deals from Sky Harbor Intl to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Sky Harbor Intl (PHX) to St. Louis (STL). 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 September 17, 2025.

Round-trip from

$211
(Kiwi.com)

One-way from

$50
(Priceline)

Popular in

January

Cheapest in

August

Average price

$345

Good round-trip deal

$302 or less

Good one-way deal

$193 or less
From Phoenix Sky Harbor Intl to Lambert-St Louis
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One-way flight from Phoenix Sky Harbor Intl to Lambert-St Louis
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Highest demand for flights based on searches. 7% potential increase in price ($29 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from Phoenix Sky Harbor Intl to Lambert-St Louis.
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Price to beat on a one-way flight from Phoenix Sky Harbor Intl to Lambert-St Louis.
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Find flight deals from Sky Harbor Intl to St. Louis

Cheapest flights from Sky Harbor Intl to St. Louis
Explore the most affordable flight options available from Sky Harbor Intl to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 17, 2025.

This Kiwi.com deal was found by Cheapflights users on 9/15. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/228:20 pmPHX - STL
1 stop10h 46mFrontier
Wed 9/247:55 pmSTL - PHX
2 stops20h 10mFrontier
Deal found 9/15$211
This Booking.com deal was found by Cheapflights users on 9/17. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/205:07 pmPHX - STL
1 stop13h 59mFrontier
Tue 9/237:55 pmSTL - PHX
1 stop27h 58mFrontier
Deal found 9/17$212
This Kiwi.com deal was found by Cheapflights users on 9/16. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/258:20 pmPHX - STL
1 stop10h 46mFrontier
Tue 9/307:55 pmSTL - PHX
2 stops18h 02mFrontier
Deal found 9/16$213
This Booking.com deal was found by Cheapflights users on 9/17. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/216:00 amPHX - STL
1 stop7h 04mFrontier
Mon 9/227:55 pmSTL - PHX
1 stop27h 58mFrontier
Deal found 9/17$215
This Kiwi.com deal was found by Cheapflights users on 9/17. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/157:30 pmPHX - STL
1 stop11h 37mFrontier
Thu 10/2310:17 amSTL - PHX
2 stops14h 38mFrontier
Deal found 9/17$216
This Kiwi.com deal was found by Cheapflights users on 9/15. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/98:58 pmPHX - STL
1 stop12h 45mFrontier
Tue 10/217:52 pmSTL - PHX
2 stops25h 13mFrontier
Deal found 9/15$217
This American Airlines deal was found by Cheapflights users on 9/15. 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.
Mon 10/136:50 pmPHX - STL
Nonstop3h 07mAmerican Airlines
Mon 10/206:21 pmSTL - PHX
Nonstop3h 21mAmerican Airlines
Deal found 9/15$219
This Kiwi.com deal was found by Cheapflights users on 9/15. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/66:00 amPHX - STL
1 stop7h 04mFrontier
Thu 10/911:32 amSTL - PHX
2 stops37h 55mFrontier
Deal found 9/15$220
This Booking.com deal was found by Cheapflights users on 9/16. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/171:02 pmPHX - STL
1 stop22h 51mFrontier
Tue 9/237:55 pmSTL - PHX
1 stop27h 58mFrontier
Deal found 9/16$224
This CheapOair deal was found by Cheapflights users on 9/16. 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.
Tue 9/308:00 amPHX - STL
1 stop23h 06mFrontier
Wed 10/87:52 pmSTL - PHX
2 stops20h 20mFrontier
Deal found 9/16$226
This American Airlines deal was found by Cheapflights users on 9/15. 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.
Fri 10/1712:18 amPHX - STL
1 stop5h 51mAmerican Airlines
Sat 10/257:31 amSTL - PHX
Nonstop3h 34mAmerican Airlines
Deal found 9/15$228
This CheapOair deal was found by Cheapflights users on 9/15. 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.
Mon 10/134:10 pmPHX - STL
2 stops14h 57mFrontier
Mon 10/207:52 pmSTL - PHX
2 stops42h 07mFrontier
Deal found 9/15$229

Cheapflights Fare Finder

 
Customize your flight search to find flights from Sky Harbor Intl to St. Louis 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 September 17, 2025.
Use the filters below to find and compare flights from Phoenix Sky Harbor Intl Airport to St. Louis that are best for you.

Fly from

Sky Harbor Intl

Fly to

St. Louis

Route

Depart

Return

Price

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Sat 12/13

3:20 pm-11:28 pm

1 stop7h 08m

Lambert-St Louis

Mon 12/15

2:20 pm-6:53 pm

1 stop5h 33m

$237

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Fri 10/17

12:40 am-8:51 am

1 stop6h 11m

Lambert-St Louis

Sat 10/25

4:45 pm-11:04 pm

1 stop8h 19m

$237

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Wed 10/15

3:25 pm-8:27 pm

Nonstop3h 02m

Lambert-St Louis

Sun 10/19

7:31 am-9:05 am

Nonstop3h 34m

$238

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Sun 9/28

6:00 am-9:06 am

1 stop25h 06m

Lambert-St Louis

Wed 10/1

7:55 pm-11:29 pm

2 stops29h 34m

$242

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Mon 10/20

6:55 pm-11:50 pm

Nonstop2h 55m

Lambert-St Louis

Thu 10/23

5:15 am-6:35 am

Nonstop3h 20m

$244

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Mon 10/13

9:59 pm-9:07 am

1 stop9h 08m

Lambert-St Louis

Thu 10/16

10:17 am-11:50 pm

2 stops15h 33m

$248

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Fri 9/26

6:00 am-1:53 pm

1 stop5h 53m

Lambert-St Louis

Sat 9/27

7:55 pm-1:47 pm

2 stops19h 52m

$256

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Mon 11/24

6:22 pm-12:46 am

1 stop5h 24m

Lambert-St Louis

Wed 12/3

7:56 pm-12:44 am

1 stop5h 48m

$277

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Thu 10/30

6:50 pm-11:57 pm

Nonstop3h 07m

Lambert-St Louis

Sun 11/2

5:00 am-10:30 am

1 stop6h 30m

$283

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Mon 10/13

12:40 am-8:51 am

1 stop6h 11m

Lambert-St Louis

Tue 10/21

6:50 am-12:15 pm

1 stop7h 25m

$288

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/16

Showing 1-10 of 18 results
1
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The best insider tips for Phoenix Sky Harbor Intl Airport to St. Louis flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your Phoenix Sky Harbor Intl Airport to St. Louis trip
Airports
PHX

PHX offers short security lines, typically under 10 minutes, ensuring a quick start to your journey to STL.

Read more about PHXby Brandon Schultz
STL

Use the MetroLink light rail from STL for a convenient, economical ride to downtown St. Louis in about 40 minutes.

Read more about STLby Taryn White
Our travel experts
Brandon Schultz

Brandon Schultz

Expert on PHX

Brandon Schultz

Brandon Schultz

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more
Taryn White

Taryn White

Expert on STL

Taryn White

Taryn White

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Read more

Best time to book a flight from Sky Harbor Intl to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Sky Harbor Intl 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 Phoenix Sky Harbor Intl Airport to St. Louis

How far ahead should I book a flight from Phoenix Sky Harbor Intl Airport to St. Louis?

Use this chart to determine the optimal time to book a round-trip flight from Sky Harbor Intl to St. Louis. Price data was last updated on September 12, 2025.

To ensure you get the cheapest price possible for a flight from Phoenix Sky Harbor Intl Airport to St. Louis, you should look to book at least 87 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Phoenix Sky Harbor Intl Airport to St. Louis?

Currently, August is the cheapest month in which you can book a flight from Phoenix Sky Harbor Intl Airport to St. Louis (average of $311). Flying from Phoenix Sky Harbor Intl Airport to St. Louis in March is currently the most expensive (average of $356). 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 PHX to STL?

Find hourly flight availability from Sky Harbor Intl to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 17, 2025.

A simple way to save on the total cost of your ticket is to fly from Phoenix Sky Harbor Intl Airport to St. Louis in the evening. If you’re flexible enough to do this you can expect to save up to 9% on your trip compared to booking a flight at noon.

What is the cheapest day to fly from Phoenix Sky Harbor Intl Airport to St. Louis?

Use this chart to determine the cheapest time to fly round-trip from Sky Harbor Intl to St. Louis. Price data was last updated on September 14, 2025.

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

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. 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 St. Louis. Reviews last updated September 17, 2025.
See what other customers who have flown with Southwest, Delta, and United Airlines from Phoenix Sky Harbor Intl Airport to St. Louis have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,242 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Southwest
8.0
Very good
4,242 reviews
Southwest
8.0
Very good
4,242 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Delta
8.0
Very good
7,961 reviews
Southwest
8.0
Very good
4,242 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
United Airlines
7.4
Good
8,926 reviews
Southwest
8.0
Very good
4,242 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
American Airlines
7.2
Good
10,000 reviews
Southwest
8.0
Very good
4,242 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Frontier
5.8
Fair
3,173 reviews
Southwest
8.0
Very good
4,242 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines

Related info for your journey

Find useful and relevant information for your journey from Sky Harbor Intl to St. Louis. 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 into for flights to St. Louis from Phoenix Sky Harbor Intl?

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

  • How long is the flight from Phoenix Sky Harbor Intl Airport to St. Louis?

    Departing from Phoenix Sky Harbor Intl Airport to St. Louis will take you 3h 02m. The distance between Phoenix Sky Harbor Intl Airport and St. Louis is about 1258 mi. Both multi-stop and nonstop flights can be found to your destination and back.

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

    Currently priced at $118, Frontier will fly you from Phoenix Sky Harbor Intl Airport to St. Louis and back. In addition to Frontier, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from United Airlines and Delta - these airlines can fly you to your destination from $198 and $236, respectively. You may be able to fly from Phoenix Sky Harbor Intl Airport to St. Louis for 70% less than the average price by searching for these airlines.

  • What are the most reliable airlines from Phoenix Sky Harbor Intl Airport to St. Louis?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Phoenix Sky Harbor Intl Airport to St. Louis on time: Southwest (81%), Alaska Airlines (80%), American Airlines (79%).

  • What are the cheapest flights from Phoenix Sky Harbor Intl Airport to St. Louis?

    While on average a flight from Phoenix Sky Harbor Intl Airport to St. Louis is generally $287, our data shows the cheapest flight currently is $148. When looking at the most popular route, (Phoenix Sky Harbor Intl - Lambert-St Louis), you can expect to pay $149 for that flight.

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

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

  • How can I find direct flights from Sky Harbor Intl to St. Louis?

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

  • Can I find deals for business class flights from Sky Harbor Intl to St. Louis?

    Yes. Cheapflights offers flight deals from Sky Harbor Intl to St. Louis 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 Phoenix Sky Harbor Intl Airport to St. Louis?

    Currently, August is the cheapest month in which you can book a flight from Phoenix Sky Harbor Intl Airport to St. Louis (average of $311). Flying from Phoenix Sky Harbor Intl Airport to St. Louis in March is currently the most expensive (average of $356). 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

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

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Alternative routes for Sky Harbor Intl to St. Louis

See prices for flight routes from nearby airports that may be better suited for you.
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Top 5 airlines flying from Sky Harbor Intl to St. Louis

Discover the top 5 airlines that operate flights from Sky Harbor Intl to St. Louis. 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 September 17, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$118Average$228FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$198Average$395FlexibilityNo cancel feeOn-time69%
DeltaCheapest$236Average$352FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$275Average$406FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$278Average$411FlexibilityNo cancel feeOn-time63%

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