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Cheap flights from Phoenix Sky Harbor Intl Airport to St. Louis from $49

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Phoenix Sky Harbor Intl Airport to St. Louis departing on 11/28. 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 Phoenix Sky Harbor Intl Airport to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
5:35 am - 5:22 pmPHX-STL
10h 47m1 stop
Frontier Logo
9:54 pm - 8:19 amSTL-PHX
11h 25m1 stop
$146Frontier
Find Deal
Sun, Nov 16 - Thu, Nov 20
Frontier Logo
3:44 pm - 7:41 pmPHX-STL
2h 57mnonstop
Frontier Logo
5:11 pm - 10:50 pmSTL-PHX
30h 39m1 stop
$153Frontier
Find Deal
Fri, Feb 20 - Sun, Feb 22
Frontier Logo
7:00 am - 10:14 amPHX-STL
26h 14m1 stop
Frontier Logo
1:16 pm - 12:44 amSTL-PHX
12h 28m2 stops
$158Frontier
Find Deal
Tue, Dec 2 - Thu, Dec 4
Frontier Logo
4:32 pm - 11:07 amPHX-STL
17h 35m2 stops
Frontier Logo
7:43 pm - 12:44 amSTL-PHX
6h 01m1 stop
$165Frontier
Find Deal
Wed, Dec 3 - Sat, Dec 6
American Airlines Logo
9:44 am - 1:51 pmPHX-STL
3h 07mnonstop
American Airlines Logo
7:38 am - 10:09 amSTL-PHX
3h 31mnonstop
$174American Airlines
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Thu, Dec 4 - Sat, Dec 6
United Airlines Logo
7:00 am - 12:39 pmPHX-STL
4h 39m1 stop
United Airlines Logo
5:27 pm - 10:57 pmSTL-PHX
6h 30m1 stop
$212United Airlines
Find Deal
Tue, Dec 9 - Tue, Dec 9
American Airlines Logo
7:55 pm - 11:51 pmPHX-STL
2h 56mnonstop
American Airlines Logo
2:29 pm - 5:05 pmSTL-PHX
3h 36mnonstop
$213American Airlines
Find Deal
Sat, Nov 15 - Tue, Nov 18
Delta Logo
12:59 am - 9:10 amPHX-STL
7h 11m1 stop
Delta Logo
6:30 am - 1:12 pmSTL-PHX
7h 42m1 stop
$217Delta
Find Deal
Mon, Dec 8 - Tue, Dec 16
United Airlines Logo
10:10 am - 4:28 pmPHX-STL
5h 18m1 stop
United Airlines Logo
1:35 pm - 5:51 pmSTL-PHX
5h 16m1 stop
$244United Airlines
Find Deal
Wed, Dec 3 - Thu, Dec 4
Southwest Logo
6:30 am - 10:20 amPHX-STL
2h 50mnonstop
Southwest Logo
5:25 pm - 7:50 pmSTL-PHX
3h 25mnonstop
$262Southwest
Find Deal
Thu, Nov 13 - Mon, Nov 17

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

Our best Frontier deals on Phoenix Sky Harbor Intl Airport to St. Louis flight tickets
Frontier
Nov 16
PHX5:35 amPhoenix Sky Harbor Intl
10h 47m
1 stop
STL5:22 pmLambert-St Louis
Nov 20
STL9:54 pmLambert-St Louis
11h 25m
1 stop
PHX8:19 amPhoenix Sky Harbor Intl
$146
Find similar
Frontier
Feb 20
PHX3:44 pmPhoenix Sky Harbor Intl
2h 57m
STL7:41 pmLambert-St Louis
Feb 22
STL5:11 pmLambert-St Louis
30h 39m
1 stop
PHX10:50 pmPhoenix Sky Harbor Intl
$153
Find similar
Frontier
Dec 2
PHX7:00 amPhoenix Sky Harbor Intl
26h 14m
1 stop
STL10:14 amLambert-St Louis
Dec 4
STL1:16 pmLambert-St Louis
12h 28m
2 stops
PHX12:44 amPhoenix Sky Harbor Intl
$158
Find similar

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

Our best Southwest deals on Phoenix Sky Harbor Intl Airport to St. Louis flight tickets
Southwest
Nov 13
PHX6:30 amPhoenix Sky Harbor Intl
2h 50m
STL10:20 amLambert-St Louis
Nov 17
STL5:25 pmLambert-St Louis
3h 25m
PHX7:50 pmPhoenix Sky Harbor Intl
$262
Find similar
Southwest
Nov 7
PHX6:20 pmPhoenix Sky Harbor Intl
2h 50m
STL10:10 pmLambert-St Louis
Nov 15
STL5:50 pmLambert-St Louis
3h 25m
PHX8:15 pmPhoenix Sky Harbor Intl
$279
Find similar
Southwest
Nov 6
PHX6:30 amPhoenix Sky Harbor Intl
2h 50m
STL10:20 amLambert-St Louis
Nov 8
STL5:25 amLambert-St Louis
3h 30m
PHX7:55 amPhoenix Sky Harbor Intl
$328
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Phoenix Sky Harbor Intl Airport 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, momondo users made 832,500 searches. Data last updated November 3, 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

Fly to

Route

Depart

Return

Price

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Sun 11/16

5:35 am-5:22 pm

1 stop10h 47m

Lambert-St Louis

Thu 11/20

9:54 pm-8:19 am

1 stop11h 25m

$146

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Fri 2/20

3:44 pm-7:41 pm

Nonstop2h 57m

Lambert-St Louis

Sun 2/22

5:11 pm-10:50 pm

1 stop30h 39m

$153

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Tue 12/2

7:00 am-10:14 am

1 stop26h 14m

Lambert-St Louis

Thu 12/4

1:16 pm-12:44 am

2 stops12h 28m

$158

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Wed 12/3

4:32 pm-11:07 am

2 stops17h 35m

Lambert-St Louis

Sat 12/6

7:43 pm-12:44 am

1 stop6h 01m

$165

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Thu 12/4

9:44 am-1:51 pm

Nonstop3h 07m

Lambert-St Louis

Sat 12/6

7:38 am-10:09 am

Nonstop3h 31m

$174

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Tue 12/9

7:00 am-12:39 pm

1 stop4h 39m

Lambert-St Louis

Tue 12/9

5:27 pm-10:57 pm

1 stop6h 30m

$212

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Sat 11/15

7:55 pm-11:51 pm

Nonstop2h 56m

Lambert-St Louis

Tue 11/18

2:29 pm-5:05 pm

Nonstop3h 36m

$213

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Mon 12/8

12:59 am-9:10 am

1 stop7h 11m

Lambert-St Louis

Tue 12/16

6:30 am-1:12 pm

1 stop7h 42m

$217

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Wed 12/3

10:10 am-4:28 pm

1 stop5h 18m

Lambert-St Louis

Thu 12/4

1:35 pm-5:51 pm

1 stop5h 16m

$244

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Thu 11/13

6:30 am-10:20 am

Nonstop2h 50m

Lambert-St Louis

Mon 11/17

5:25 pm-7:50 pm

Nonstop3h 25m

$262

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 St. Louis from

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

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 St. Louis?

In general, November is the cheapest month to fly from Phoenix Sky Harbor Intl Airport to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $337. The month of October is another great option to travel to St. Louis, with average flight prices from Phoenix Sky Harbor Intl Airport averaging around $338.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Tuesday when prices can be found for as low as $374. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $449. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Phoenix Sky Harbor Intl Airport in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $397 when looking at flights departing in the afternoon. At noon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $413 per ticket.

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

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

How far in advance should I book a flight to St. Louis?

You are more likely to see cheaper flights to St. Louis from Phoenix Sky Harbor Intl Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $391 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Phoenix Sky Harbor Intl Airport for as low as $342 on momondo.

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

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

Can stopping save me money on Phoenix Sky Harbor Intl Airport to St. Louis flights?

No. A direct flight is the cheapest option for a flight between Phoenix Sky Harbor Intl Airport to St. Louis.

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

As of November 2025, prices for Phoenix Sky Harbor Intl Airport to St. Louis flights are approximately 30% more expensive when compared to flights at the same time last year.

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

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

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

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

Best Price Found

$143

Fastest flight time

2h 45m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Phoenix Sky Harbor Intl Airport in the past 72 hours is $143. The best round-trip flight deal from Phoenix Sky Harbor Intl Airport to St. Louis found on momondo in the last 72 hours is $229.
The fastest flight from Phoenix Sky Harbor Intl Airport to St. Louis takes 2h 45m
Direct flights go from Phoenix Sky Harbor Intl Airport to St. Louis every day.
There is 1 airport near St. Louis: Lambert-St Louis (STL)
Search flight deals

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

    The straight-line distance from Phoenix Sky Harbor Intl to Lambert-St Louis is 1265.4 mi. 2h 50m is a normal flight duration for this route.

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

    Prices for flights from Phoenix Sky Harbor Intl Airport to Lambert-St Louis Airport refresh daily.

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

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

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Phoenix Sky Harbor Intl Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

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

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

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

Compare and see reviews for airlines that fly from Phoenix Sky Harbor Intl Airport to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $113Free CancellationRating
5.8
3,118 reviews
Search Frontier flights
United AirlinesPriceFrom $198Free CancellationRating
7.4
8,997 reviews
Search United Airlines flights
American AirlinesPriceFrom $253Free CancellationRating
7.2
11,034 reviews
Search American Airlines flights
DeltaPriceFrom $259Free CancellationRating
7.9
8,001 reviews
Search Delta flights
SouthwestPriceFrom $276Free CancellationRating
8.0
4,240 reviews
Search Southwest flights

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

    Across 26 Southwest flights from Phoenix Sky Harbor Intl Airport to St. Louis this week, the average price was $406, with the best Southwest deals starting from $276 round-trip. 4,240 users have rated Southwest on momondo, with an average score of 8.0/10.

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

    $253 is the best American Airlines flight deal from Phoenix Sky Harbor Intl Airport to St. Louis found on momondo over the last 72 hours. The average American Airlines ticket price found was closer to $401, however, with flight time and availability significantly affecting the price. American Airlines (7.2/10 from 11,034 user reviews) flies into St. Louis from Phoenix Sky Harbor Intl Airport 10 times in an average week so prices can vary.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Fairview Heights
Florissant
Maryland Heights
O'Fallon
Wentzville
Fenton
Collinsville
St. Peters
Alton
Farmington
Festus
Glencoe
Edwardsville
Clayton
Eureka
Litchfield
Shrewsbury

Why use momondo?

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

Finding the right flight to St. Louis from Phoenix is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to St. Louis quick and easy, saving you time and money.

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

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

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

momondo helps you find the best flight between Phoenix and St. Louis by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

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

If you are not ready to book a flight from Phoenix to St. Louis now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to St. Louis and let you know when they change.

An easier way to manage your St. Louis trip

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