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Cheap flights from St. Louis to Phoenix from $43

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Phoenix departing on 10/10. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from St. Louis to Phoenix

Cheap round-trip flights

Frontier Logo
10:59 pm - 12:21 amSTL-PHX
3h 22mnonstop
Frontier Logo
2:27 pm - 7:26 pmPHX-STL
2h 59mnonstop
$73Frontier
Find Deal
Fri, Oct 24 - Mon, Oct 27
Frontier Logo
10:59 pm - 12:21 amSTL-PHX
3h 22mnonstop
Frontier Logo
2:27 pm - 7:26 pmPHX-STL
2h 59mnonstop
$76Frontier
Find Deal
Fri, Oct 10 - Mon, Oct 13
Frontier Logo
1:54 pm - 4:16 pmSTL-PHX
3h 22mnonstop
Frontier Logo
8:00 am - 11:59 amPHX-STL
2h 59mnonstop
$78Frontier
Find Deal
Fri, Nov 7 - Mon, Nov 10
Frontier Logo
7:52 pm - 11:29 pmSTL-PHX
5h 37m1 stop
Frontier Logo
2:27 pm - 7:26 pmPHX-STL
2h 59mnonstop
$110Frontier
Find Deal
Thu, Oct 9 - Mon, Oct 13
Frontier Logo
10:59 pm - 12:21 amSTL-PHX
3h 22mnonstop
Frontier Logo
9:59 pm - 9:07 amPHX-STL
9h 08m1 stop
$139Frontier
Find Deal
Fri, Oct 10 - Mon, Oct 13
Frontier Logo
7:55 pm - 10:01 amSTL-PHX
16h 06m1 stop
Frontier Logo
6:18 pm - 9:06 amPHX-STL
12h 48m1 stop
$143Frontier
Find Deal
Sat, Sep 6 - Fri, Sep 12
Frontier Logo
7:55 pm - 9:53 pmSTL-PHX
27h 58m1 stop
Frontier Logo
6:18 pm - 9:07 amPHX-STL
12h 49m1 stop
$144Frontier
Find Deal
Fri, Oct 3 - Mon, Oct 6
American Airlines Logo
2:29 pm - 5:05 pmSTL-PHX
3h 36mnonstop
American Airlines Logo
9:36 am - 1:40 pmPHX-STL
3h 04mnonstop
$161American Airlines
Find Deal
Wed, Nov 5 - Sat, Nov 8
Southwest Logo
8:45 pm - 10:05 pmSTL-PHX
3h 20mnonstop
Southwest Logo
7:35 pm - 12:30 amPHX-STL
2h 55mnonstop
$209Southwest
Find Deal
Tue, Oct 7 - Tue, Oct 28
American Airlines Logo
2:29 pm - 5:05 pmSTL-PHX
3h 36mnonstop
American Airlines Logo
7:54 pm - 11:50 pmPHX-STL
2h 56mnonstop
$211American Airlines
Find Deal
Thu, Nov 6 - Tue, Nov 11

Frontier flights from St. Louis to Phoenix Sky Harbor Intl Airport

Our best Frontier deals on St. Louis to Phoenix Sky Harbor Intl Airport flight tickets
Frontier
Oct 24
STL10:59 pmLambert-St Louis
3h 22m
PHX12:21 amPhoenix Sky Harbor Intl
Oct 27
PHX2:27 pmPhoenix Sky Harbor Intl
2h 59m
STL7:26 pmLambert-St Louis
$73
Find similar
Frontier
Oct 10
STL10:59 pmLambert-St Louis
3h 22m
PHX12:21 amPhoenix Sky Harbor Intl
Oct 13
PHX2:27 pmPhoenix Sky Harbor Intl
2h 59m
STL7:26 pmLambert-St Louis
$76
Find similar
Frontier
Nov 7
STL1:54 pmLambert-St Louis
3h 22m
PHX4:16 pmPhoenix Sky Harbor Intl
Nov 10
PHX8:00 amPhoenix Sky Harbor Intl
2h 59m
STL11:59 amLambert-St Louis
$78
Find similar

American Airlines flights from St. Louis to Phoenix Sky Harbor Intl Airport

Our best American Airlines deals on St. Louis to Phoenix Sky Harbor Intl Airport flight tickets
American Airlines
Nov 5
STL2:29 pmLambert-St Louis
3h 36m
PHX5:05 pmPhoenix Sky Harbor Intl
Nov 8
PHX9:36 amPhoenix Sky Harbor Intl
3h 04m
STL1:40 pmLambert-St Louis
$161
Find similar
American Airlines
Nov 6
STL2:29 pmLambert-St Louis
3h 36m
PHX5:05 pmPhoenix Sky Harbor Intl
Nov 11
PHX7:54 pmPhoenix Sky Harbor Intl
2h 56m
STL11:50 pmLambert-St Louis
$211
Find similar
American Airlines
Aug 26
STL7:53 amLambert-St Louis
3h 15m
PHX9:08 amPhoenix Sky Harbor Intl
Sep 4
PHX12:59 pmPhoenix Sky Harbor Intl
3h 01m
STL6:00 pmLambert-St Louis
$322
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Phoenix Sky Harbor Intl Airport 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, momondo users made 832,500 searches. Data last updated August 16, 2025.
Use the filters below to find and compare flights from St. Louis to Phoenix Sky Harbor Intl Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Fri 10/24

10:59 pm-12:21 am

Nonstop3h 22m

Phoenix Sky Harbor Intl

Mon 10/27

2:27 pm-7:26 pm

Nonstop2h 59m

$73

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Fri 10/10

10:59 pm-12:21 am

Nonstop3h 22m

Phoenix Sky Harbor Intl

Mon 10/13

2:27 pm-7:26 pm

Nonstop2h 59m

$76

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Fri 11/7

1:54 pm-4:16 pm

Nonstop3h 22m

Phoenix Sky Harbor Intl

Mon 11/10

8:00 am-11:59 am

Nonstop2h 59m

$78

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Thu 10/9

7:52 pm-11:29 pm

1 stop5h 37m

Phoenix Sky Harbor Intl

Mon 10/13

2:27 pm-7:26 pm

Nonstop2h 59m

$110

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Fri 10/10

10:59 pm-12:21 am

Nonstop3h 22m

Phoenix Sky Harbor Intl

Mon 10/13

9:59 pm-9:07 am

1 stop9h 08m

$139

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Sat 9/6

7:55 pm-10:01 am

1 stop16h 06m

Phoenix Sky Harbor Intl

Fri 9/12

6:18 pm-9:06 am

1 stop12h 48m

$143

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Fri 10/3

7:55 pm-9:53 pm

1 stop27h 58m

Phoenix Sky Harbor Intl

Mon 10/6

6:18 pm-9:07 am

1 stop12h 49m

$144

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Wed 11/5

2:29 pm-5:05 pm

Nonstop3h 36m

Phoenix Sky Harbor Intl

Sat 11/8

9:36 am-1:40 pm

Nonstop3h 04m

$161

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Tue 10/7

8:45 pm-10:05 pm

Nonstop3h 20m

Phoenix Sky Harbor Intl

Tue 10/28

7:35 pm-12:30 am

Nonstop2h 55m

$209

St. LouisPhoenix

STL - PHX

STLPHX

Lambert-St Louis

Thu 11/6

2:29 pm-5:05 pm

Nonstop3h 36m

Phoenix Sky Harbor Intl

Tue 11/11

7:54 pm-11:50 pm

Nonstop2h 56m

$211

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Phoenix from

How to get the cheapest flight ticket from St. Louis to Phoenix Sky Harbor Intl Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Phoenix Sky Harbor Intl Airport?

In general, September is the cheapest month to fly from St. Louis to Phoenix Sky Harbor Intl Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $317. If you are unable to visit Phoenix Sky Harbor Intl Airport during the month of September, then departing from St. Louis during the month August is also very affordable. Most momondo users find prices during this month for around $335.

What is the cheapest day to depart on your flight to Phoenix Sky Harbor Intl Airport?

On average, the least expensive day to fly to Phoenix Sky Harbor Intl Airport from St. Louis is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as $392. However, this price may fluctuate depending on the airline, the season, and holidays. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $491. These prices are subject to change though, so be sure to set up a Price Alert for flights to Phoenix Sky Harbor Intl Airport.

What is the cheapest time of day to depart on your flight to Phoenix Sky Harbor Intl Airport?

At noon is the cheapest time of day to fly from St. Louis to Phoenix Sky Harbor Intl Airport when you can find flight prices for as low as $399. Flying to Phoenix Sky Harbor Intl Airport at noon is an ideal time because this is during off-peak travel hours. Try not to purchase tickets in the morning because they tend to be around $449. Of course, these prices can vary depending on the time of year and what airport you fly to.

What is the cheapest Lambert-St Louis to Phoenix Sky Harbor Intl flight route?

Fly from Lambert-St Louis to Phoenix Sky Harbor Intl for the best Lambert-St Louis - Phoenix Sky Harbor Intl flight prices

How far in advance should I book a flight to Phoenix Sky Harbor Intl Airport?

You are more likely to see cheaper flights to Phoenix Sky Harbor Intl Airport from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Phoenix Sky Harbor Intl Airport for around $391 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Phoenix Sky Harbor Intl Airport from St. Louis for as low as $352 on momondo.

What cabin class options are available on Lambert-St Louis to Phoenix Sky Harbor Intl flights?

There are 3 cabin classes available to choose from on Lambert-St Louis to Phoenix Sky Harbor Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have St. Louis to Phoenix Sky Harbor Intl Airport flight prices changed over time?

As of August 2025, prices for St. Louis to Phoenix Sky Harbor Intl Airport flights are approximately 7% cheaper when compared to flights at the same time last year.

When to book flights from St. Louis to Phoenix Sky Harbor Intl Airport

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Phoenix Sky Harbor Intl Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap St. Louis to Phoenix Sky Harbor Intl Airport (STL to PHX) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Phoenix Sky Harbor Intl Airport

Best Price Found

$43

Fastest flight time

3h 15m

Direct flights

Every day
The best one-way flight to Phoenix Sky Harbor Intl Airport from St. Louis in the past 72 hours is $43. The best round-trip flight deal from St. Louis to Phoenix Sky Harbor Intl Airport found on momondo in the last 72 hours is $73.
The fastest flight from St. Louis to Phoenix Sky Harbor Intl Airport takes 3h 15m
Direct flights go from St. Louis to Phoenix Sky Harbor Intl Airport every day.
Search flight deals

  • How far is Lambert-St Louis to Phoenix Sky Harbor Intl by plane?

    Phoenix Sky Harbor Intl is 1265.4 mi away from Lambert-St Louis. Typically, this will take 3h 20m by plane in normal conditions.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Phoenix Sky Harbor Intl Airport?

    Prices for flights from Lambert-St Louis Airport to Phoenix Sky Harbor Intl Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to Phoenix Sky Harbor Intl Airport?

  • How old do you have to be to fly from Lambert-St Louis Airport to Phoenix Sky Harbor Intl Airport?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Lambert-St Louis Airport to Phoenix Sky Harbor Intl Airport.

  • What documentation or ID do you need to fly to Phoenix Sky Harbor Intl Airport?

    The travel and health documents you'll need for your trip to Phoenix Sky Harbor Intl Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Phoenix Sky Harbor Intl Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from St. Louis to Phoenix Sky Harbor Intl Airport?

  • What is the most popular airline from St. Louis to Phoenix Sky Harbor Intl Airport?

Best airlines flying from St. Louis to Phoenix Sky Harbor Intl Airport

Compare and see reviews for airlines that fly from St. Louis to Phoenix Sky Harbor Intl Airport with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $108Free CancellationRating
5.8
3,211 reviews
Search Frontier flights
Spirit AirlinesPriceFrom $154Free CancellationRating
6.3
8,042 reviews
Search Spirit Airlines flights
United AirlinesPriceFrom $223Free CancellationRating
7.4
8,916 reviews
Search United Airlines flights
American AirlinesPriceFrom $231Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
DeltaPriceFrom $236Free CancellationRating
8.0
7,985 reviews
Search Delta flights
SouthwestPriceFrom $276Free CancellationRating
8.0
4,246 reviews
Search Southwest flights

  • Southwest Flights From St. Louis to Phoenix Sky Harbor Intl Airport

    Southwest operates around 25 flights from St. Louis to Phoenix Sky Harbor Intl Airport every week. The average price of these flights found in the last 72 hours has been $434, but momondo users have found Southwest deals from St. Louis to Phoenix Sky Harbor Intl Airport from as low as $276 round-trip. Southwest has been scored 8.0/10 in 4,246 reviews.

  • American Airlines Flights From St. Louis to Phoenix Sky Harbor Intl Airport

    American Airlines (7.2/10 from 10,000 reviews) operates around 9 flights from St. Louis to Phoenix Sky Harbor Intl Airport in any given week. The average American Airlines airfare for this route is around $409, with deals from around $231 rare but found on momondo. Referenced prices are for round-trip St. Louis to Phoenix Sky Harbor Intl Airport flight searches in the last 72 hours.

Traveling to a place near Phoenix?

Book flights to Phoenix if you plan to visit one of these locations
Scottsdale
Mesa
Tempe
Glendale
Chandler
Gilbert
Peoria
Surprise
Casa Grande
Buckeye
Wickenburg
Apache Junction
Goodyear
Payson
Paradise Valley
Avondale
Camp Verde
Fountain Hills
Cave Creek
Litchfield Park

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Phoenix?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from St. Louis to Phoenix. momondo saves you time and could save you money on your trip.

Can I find flights from St. Louis to Phoenix with flexible booking policies on momondo?

momondo does allow users to show only those flights to Phoenix from St. Louis which offer a flexible booking policy as well as other useful filters and features.

How can momondo help me find flights from St. Louis to Phoenix?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Phoenix from St. Louis.

I’m not ready to book a flight from St. Louis to Phoenix right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Phoenix, momondo offers a useful price alert feature which will track prices for flights to Phoenix from St. Louis and alert you when they change.

An easier way to manage your Phoenix Sky Harbor Intl Airport trip

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