PHX - STL

$29 Find Cheap Flights from Phoenix to St. Louis

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Phoenix to St. Louis departing on 2/23. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to St. Louis

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Phoenix to St. Louis, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Phoenix to St. Louis, as well as popular online travel agencies
Travelers love KAYAK
41 299 237 searches in the past 7 days on KAYAK

Save 23% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Everything you should know

Cheapest round-trip
$58
Overall average: $375
Frontier
Mon 2/23Mon 3/2
PHX - STL • Non-stop
Cheapest one-way
$29
Typical prices: $161-$400
Frontier
Mon 2/23
PHX - STL • Non-stop
Our travelers' advice
AI-powered summary based on content written by travel experts. AI can make mistakes.
Southwest's two free checked bags benefit travelers.
Use MetroLink for easy downtown access from STL.
Expert advice
Expert advice
Expert advice
Expert advice
Video guide: How to find cheap flights to St. Louis
Watch video
Watch video
Watch video
Watch video
When to book
3 weeks
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 17% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
December
Cheapest • 10% price drop
July
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to St. Louis!
Flight Deals
Booking Insights
Expert advice
Flight Deals

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

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Phoenix to St. Louis that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Phoenix to St. Louis

Mon, Feb 23 - Mon, Mar 2
Frontier Logo
4:09 pm - 8:02 pm
PHX
-
STL
2h 53mnonstop
Frontier Logo
8:47 pm - 11:28 pm
STL
-
PHX
3h 41mnonstop
$58Frontier
Fri, Feb 20 - Mon, Feb 23
Frontier Logo
4:14 pm - 8:07 pm
PHX
-
STL
2h 53mnonstop
Frontier Logo
8:47 pm - 11:28 pm
STL
-
PHX
3h 41mnonstop
$78Frontier
Fri, Feb 20 - Mon, Feb 23
Frontier Logo
10:39 pm - 1:56 pm
PHX
-
STL
14h 17m
1 stop
Frontier Logo
8:47 pm - 11:28 pm
STL
-
PHX
3h 41mnonstop
$104Frontier
Mon, Feb 23 - Mon, Mar 2
Frontier Logo
4:09 pm - 8:02 pm
PHX
-
STL
2h 53mnonstop
Frontier Logo
10:11 pm - 6:54 pm
STL
-
PHX
21h 43m
1 stop
$119Frontier
Fri, Feb 20 - Mon, Feb 23
Frontier Logo
6:00 am - 1:09 pm
PHX
-
STL
6h 09m
1 stop
Frontier Logo
8:47 pm - 11:28 pm
STL
-
PHX
3h 41mnonstop
$126Frontier
Fri, Feb 6 - Sun, Feb 8
Frontier Logo
8:15 am - 12:08 pm
PHX
-
STL
2h 53mnonstop
Frontier Logo
1:03 pm - 3:44 pm
STL
-
PHX
3h 41mnonstop
$127Frontier
Wed, Feb 25 - Sat, Feb 28
Frontier Logo
9:52 am - 3:53 pm
PHX
-
STL
5h 01m
1 stop
Frontier Logo
2:51 pm - 11:59 pm
STL
-
PHX
10h 08m
1 stop
$128Frontier
Wed, Feb 25 - Sun, Mar 1
Frontier Logo
6:00 am - 3:53 pm
PHX
-
STL
8h 53m
1 stop
Frontier Logo
10:11 pm - 8:34 pm
STL
-
PHX
23h 23m
1 stop
$129Frontier
Wed, Feb 18 - Thu, Feb 26
Frontier Logo
8:04 pm - 9:26 pm
PHX
-
STL
24h 22m
1 stop
Frontier Logo
10:11 pm - 8:50 am
STL
-
PHX
11h 39m
1 stop
$131Frontier
Wed, Feb 11 - Fri, Feb 13
Frontier Logo
6:00 am - 1:58 pm
PHX
-
STL
6h 58m
1 stop
Frontier Logo
10:11 pm - 1:55 pm
STL
-
PHX
16h 44m
1 stop
$132Frontier
Booking Insights

KAYAK's insights & trends for Phoenix to St. Louis flights

Get data-powered insights and trends into flights from Phoenix to St. Louis to help you find the cheapest flights, the best time to fly and much more.

Find cheap flights to St. Louis
Find cheap flights to St. Louis

Planning a trip from Phoenix to St. Louis? KAYAK’s data-powered insights will help you find cheap flights. Learn the best time to fly, how early to book your ticket, and other tips to secure great prices.

What’s the cheapest day of the week to fly from Phoenix to St. Louis?

The average price of all round-trip flights from Phoenix Sky Harbor Intl Airport to St. Louis clicked on KAYAK for each day over the last 12 months.

Your flight ticket price will generally be cheaper if you fly to St. Louis on a Friday and more expensive on a Sunday. On your return trip to Phoenix, you should consider flying back on a Wednesday, and avoid Sundays for better deals.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Phoenix Sky Harbor Intl Airport to St. Louis, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Phoenix Sky Harbor Intl Airport to St. Louis is December, where tickets cost $333 (return) on average. On the other hand, the most expensive months are April and June, where the average cost of round-trip tickets is $420 and $397 respectively.

Can I save money by flying with a layover from Phoenix Sky Harbor Intl Airport to St. Louis?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of $337, prices are generally cheapest when you fly direct.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Phoenix Sky Harbor Intl Airport to St. Louis, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Phoenix Sky Harbor Intl Airport to St. Louis, you should book around 3 weeks before departure, which saves you about 17% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 4 weeks before departure.

Expert advice

Expert advice for your flight from Phoenix to St. Louis

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Blane Bachelor

Blane Bachelor

Expert on Southwest

Blane Bachelor is a journalist and editor specializing in travel and aviation who writes regularly for top global outlets. Born and raised in Florida, Blane has worked and lived in four countries, including the Netherlands, where she’s currently based with her family. Her favorite way to get to know a new destination is by running or riding a bike around town – or hearing a spooky ghost story about local history. She will always choose the window seat.

Harriet Baskas

Harriet Baskas

Expert on American Airlines

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Laura Ratliff

Laura Ratliff

Expert on PHX

Laura Ratliff is a New York-based writer and editor. She lives in downtown Brooklyn with her husband and their beloved dogs. Originally from Texas, she now considers New York City her home. She typically spends more than 200,000 miles on a plane each year and stays in plenty of hotels.

Yulia Denisyuk

Yulia Denisyuk

Expert on STL

Yulia is a freelance journalist who’s dispatched from 90+ countries. Her work focuses on cultures, adventure trips and air travel, appearing in NatGeo, NYT, CNTraveler, and more. For past assignments, she’s stayed with nomads in Mongolia and learned the art of Imigongo in Rwanda. She’s based in Chicago; in winter she often questions that decision.

Good to know

Low seasonDecember
Cheapest flight$29
Best time to beat the crowds with an average 10% drop in price.
Most popular time to fly with an average 6% increase in price.
Flight from Phoenix to St. Louis

When to book flights from Phoenix to St. Louis

Are your dates flexible? Find out the best times to travel from Phoenix to St. Louis based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking Phoenix to St. Louis flights

  • Where can passengers sleep at Lambert International Airport?

    Seating with armrests is available in several locations across the airport, most of which are in Terminal 2 and Concourse C. It is recommended by reviewers that you bring a sleeping bag, travel blanket, or additional layers of clothing with you if you want to sleep at this airport since it is believed to be very chilly.

  • Are there any kid-friendly amenities at Lambert International Airport?

    Near gate C3 at STL is a play area designated specifically for children. This is an educational play exhibit with a transportation-based theme that has a child-sized facsimile of a light rail train and a MetroLink train as well as a child-sized airplane and air traffic control tower.

  • How can I get to downtown St. Louis from STL airport?

    If you are traveling downtown, using Metrolink is an option that is not only speedy but also affordable and easy. The St. Louis International Airport (STL) is about 15 miles from the city's central business district. It takes around 19min to complete.

  • How do I get from downtown Phoenix to PHX airport?

    No rail can take passengers directly from downtown Phoenix to the terminal building at the Phoenix airport. To begin, you will need to ride a Valley Metro Rail train to the rail station at 44th Street and Washington and then transfer to the free PHX Sky Train® to go to Terminal 3 or 4. The entire amount of time spent traveling is around half an hour.

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

    In the last 3 days, the lowest price for a flight from Phoenix Sky Harbor Intl Airport to St. Louis was $29 for a one-way ticket and $58 for a round-trip.

  • Do I need a passport to fly between Phoenix and St. Louis?

    No, a passport isn't needed to fly from Phoenix to St. Louis. However, local authorities might ask for an official ID.

  • Which airports will I be using when flying from Phoenix to St. Louis?

    On your way to St. Louis, you’ll fly out from Phoenix Sky Harbor Intl. You’ll be landing at Lambert-St Louis.

  • Which airlines offer Wi-Fi service onboard planes from Phoenix to St. Louis?

    American Airlines, JetBlue, and Delta offer inflight Wi-Fi service on the Phoenix to St. Louis flight route.

  • Which aircraft models fly most regularly from Phoenix to St. Louis?

    The Boeing 737 MAX 8 is the aircraft model that flies most regularly on the Phoenix to St. Louis flight route.

  • Which airline alliances offer flights from Phoenix to St. Louis?

    SkyTeam, and oneworld are the airline alliances operating flights between Phoenix and St. Louis, with SkyTeam being the most commonly used for this route.

  • On which days can I fly direct from Phoenix to St. Louis?

    There are nonstop flights from Phoenix to St. Louis on a daily basis.

  • Which is the best airline for flights from Phoenix to St. Louis, Southwest or Delta?

    The two airlines most popular with KAYAK users for flights from Phoenix to St. Louis are Southwest and Delta. With an average price for the route of $398 and an overall rating of 8.0, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $367 and an overall rating of 7.9.

  • How does KAYAK find such low prices on flights from Phoenix to St. Louis?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Phoenix to St. Louis.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Phoenix to St. Louis?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Louis from Phoenix is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Phoenix to St. Louis?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Louis with an airline and back to Phoenix with another airline. Booking your flights between Phoenix and STL can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Phoenix to St. Louis?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Louis from Phoenix up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Phoenix Sky Harbor Intl Airport to St. Louis

  • Looking for a cheap flight? 25% of our users found flights on this route for $115 or less one-way and $224 or less round-trip.
  • Both within and outside of the terminals of Sky Harbor International Airport (PHX) are designated locations for pets to relieve themselves. The airport has eight locations for dogs to relieve themselves, drink water, and stretch their legs during layovers (mitts for cleaning up provided).
  • Is your journey to Phoenix taking longer than you thought, and do you need to keep your vehicle at Sky Harbor International Airport for a longer period than you first planned? The covered parking garage and the open parking lot are available to passengers who need to keep their automobiles at PHX for an extended period.
  • No matter which airline a customer is flying with, they are eligible to get a reduced rate to enter any of the lounges located in PHX. This is the greatest choice if you need to connect planes, if your trip was canceled, if you need to check in early in the morning, or if you want breakfast.
  • Phoenix Sky Harbor International Airport and Lambert International Airport (STL) provide services to assist guests who may have difficulties moving about the airport. Feel free to inquire about the assistance in renting a wheelchair and navigating the airport either before or after you go on your vacation. If you wish to use these services, you must give the airline plenty of notice in advance.
  • It is highly advised to pick up your rental automobile from Lambert International Airport as soon as you touch down. Passengers do not have to wait for a shuttle to a far-off place since there is a vehicle rental counter at the airport. Time is of the essence when it comes to renting an automobile.

Prefer to fly direct from Phoenix to St. Louis?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Phoenix Sky Harbor Intl to Lambert-St Louis.
Find which airlines fly direct from Phoenix Sky Harbor Intl Airport to Lambert-St Louis Airport, which days they fly and book direct flights.

Direct departures

Phoenix Sky Harbor Intl to Lambert-St Louis

Monday

American Airlines, Frontier, Southwest

American Airlines, Frontier, +1 more

Tuesday

American Airlines, Southwest

American Airlines, Southwest

Wednesday

American Airlines, Southwest

American Airlines, Southwest

Thursday

American Airlines, Southwest, Frontier

American Airlines, Southwest, +1 more

Friday

American Airlines, Frontier, Southwest

American Airlines, Frontier, +1 more

Saturday

American Airlines, Southwest

American Airlines, Southwest

Sunday

American Airlines, Frontier, Southwest

American Airlines, Frontier, +1 more

See more direct flights

Direct returns

Lambert-St Louis to Phoenix Sky Harbor Intl

Monday

American Airlines, Frontier, Southwest

American Airlines, Frontier, +1 more

Tuesday

American Airlines, Southwest

American Airlines, Southwest

Wednesday

American Airlines, Southwest

American Airlines, Southwest

Thursday

American Airlines, Southwest, Frontier

American Airlines, Southwest, +1 more

Friday

American Airlines, Frontier, Southwest

American Airlines, Frontier, +1 more

Saturday

American Airlines, Southwest

American Airlines, Southwest

Sunday

American Airlines, Frontier, Southwest

American Airlines, Frontier, +1 more

See more direct flights

Reviews of the top 4 airlines serving from Phoenix to St. Louis

 
See real verified KAYAK customer reviews for airlines flying from Phoenix to St. Louis. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Phoenix to St. Louis? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4266 reviews
8.6Crew
7.0Food
8.1Boarding
8.0Comfort
7.5Entertainment
Airline reviews

Great flight but super high price. Glad it was a business trip and not personal

10.0 ExcellentPieter, Jan 2026
LGB - DAL
Read more Southwest reviews

Great flight but super high price. Glad it was a business trip and not personal

On time. Friendly staff. Took to long to pre bord all the specialty groups. Cramped small plane

The seats were comfortable, and the boarding process was pretty smooth.

3 hour delay. Had to change plans and was still delayed.

The staff was very friendly, professional, and courteous. The overall flight was a great experience.

The crew canceled the complementary snack and drink in anticipation of turbulence that never materialized. I was counting on the drink (water) to take the the doses of medication - prescribed for my heart condition - that were due during the flight. Since no snack or meal was served on this flight, I cannot rate the food quality. Otherwise, this flight was excellent.

Departure was delayed more than 1/2 hour while we waited for luggage (only) transfer from another flight/plane. Once approved for takeoff, the flight was excellent.

We got exit row seats both flights. Everything was running on time

The flight crew was extremely rude and especially not helpful when our flight was delayed.

Pretty seamless, just a tad bit late in taking off and landing.

There was no wifi available on this flight. And there were no screens, no onboard entertainment, no entertainment options at all. It was like travelling in the 1990s again, except without even a main screen for options. Seats, as usual, were tight and uncomfortable.

Good seat comfort ORF to ATL. Bad seat ATL to SEA (terrible lumbar support, hard, ouch)..

Because I was moved to an exit row, the snacks in economy comfort, the selection of snacks was better.

I upgraded to first. Quick and easy boarding. Comfortable seat with power and a nice IPA.

Probably not the fault of Delta but there was delay after delay after delay and I ended up getting home 4 hours later then I should have at 1:30 in the morning

No in flight service, no explanation - FC got service, C+ did not, unsure about Economy. No turbulence to speak of, so I guess another way to cut cost, or promote health and well being of Delta employees? Also, boarding in MEM combined zones, and with overhead space already full on both flights after Zone 2/ Diamond, presents a huge challenge to find a space for a bag. Delta, other than point A to B, is no longer reasonable to fly - very poor experiences, not even taking into account the chastising at the gate and rude crews, across the board.

It would have been better if the flight wasn't delayed by 2.5 hours

Delta’s staff is unmatched. From the gate agents, to the pilots, to the flight attendants… all top of the industry.

Delta flight Delay for ,more that two hours i.e original flight was 6.30 PM and it starts at 8.45 PM, When we connect Delta team for meal vouchers as it is late arrival in designation,But we did not get it as per delta policy , which is not good for mid night arrival,

Inexperienced boarding crew allowed too many bags on to a full flight and delayed takeoff causing a missed connection and unplanned overnight stay. There was a hotel at the airport but Delta would not pay for it offering only to shuttle me to an area hotel. Never even offerred so much as an apology by anyone working for Delta.

Amazing I love American. I’ll never fly anyone else if I can help it.

Experience was good. We were delayed in leaving by 15 mins because the flight was waiting on a family that was late in getting to the gate. Food and drink options were as expected. I highly recommend checking in ahead of time using the airline’s app so that it’s quicker to get your luggage tags as soon as you arrive at the terminal. No more waiting in long lines!

The captain brought my 6 year old son into the cockpit and allowed him to ask questions, sit in the captain’s chair and talk about all the gears and levers. Made the trip very special for him.

Better service. No food options, but we did get drinks and a cookie.

it was fine, decent flight... dont get food besides cookies or pretzels so not sure why you ask about food. same for entertainment..

Liked that it was on time. Staff professional and friendly.

More choices on snacks. Built-in video screen to enjoy entertainment choices.

Loved the crew . Absolutely no complaints. Except for luggage lost

this plane was really old, had exit row seats and tray was in arm of seat so super uncomfortable to use. another seat they could t even use the tray it was broke. seat i. front of me had duct tape on it cause seat was ripped open... this plane should either be updated or retired.

We are too tired and frustrated to comment politely at this point

Good for a budget airline! It was easy to get on, staff was really nice. Can’t say anything about the food or entertainment because it wasn’t available, which is fine.

I am writing to express my disappointment with my recent Frontier Airlines flight. I was charged $99 at the gate because my bag was said to be too large, yet once onboard there was no available overhead bin space, and I was required to place the bag under the seat in front of me anyway. This made the charge feel unnecessary and unfair. Additionally, before the flight even took off, I was asked to move from the seat I paid for into a middle seat so another passenger and her cat could have my seat to themselves. I was not offered compensation or an explanation for being moved from a paid seat. Between the unexpected bag fee and being forced to give up my seat, this experience fell well below acceptable customer service standards. I would appreciate a review of this situation and appropriate compensation.

It was costly and difficult to check in. $85 to take a small suitcase with me, carry on or checked and $75 on the return trip, Plus $25 if I didn't check my self in check in $25, because I couldn't do it on the kiosk. Small very uncomfortable seats, waited on the runway for near an hour each way. It was my worst flight to date.

It was ok. It was expensive to check 2 bags ($75.00 per bag), and then it took a long time to wait for shuttle to take us from one terminal to the terminal where the plane was taking off at LAX. And all of this for a flight where we had to pay for any food or drink that was not water.

It didn’t happen. I booked it and then was told it wasn’t available and then forced to pay far higher prices for a worse option

A 630departure flight Delayed 6hours! They changed my gate, I moved to the new gate. Had our flight on the screen for 12noon departure. I go get above to eat, check screen again and the flight was gone, no notice no announcement, nothing!! They sent my bag on the flight I wasn’t on, got it back to me 3days later. Thank goodness they did refund my money but I will NEVER fly them again.

Due to weather, my flight was delayed, further delayed, then canceled. I eventually got through to a support person who helped me find a different route out of MSP, but to get to DIA, they didn't want to, but eventually did help with the connection ticket purchase. But even this replacement flight was delayed time and time again, and I would have missed my connecting flights and I didn't want to get stuck in a layover city, so after 12 hours at the airport with two young boys who were very tired, we just cancelled our plans and spent the week at home, instead of Nana's.

Plane and crew on board were fine. Everything else was terrible.

The third party booking with cheapflightsfares was awful. Kayak should NOT partner with them. They sold me a bundle including seat selection and carry-on, but did not book the carry-ons with Frontier, so I’m out of pocket for $414 more while I await resolution.

This company socks. It's fraud. They canceled our flight yesterday, and today we were late because of a really long line at the check in bag. At the rebook station, there was ton of people. The workers were all rude. I am gonna make a report to FTC.

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

Other airlines flying from Phoenix to St. Louis

Flights from the other most popular airlines that fly from Phoenix to St. Louis according to KAYAK users. Prices are the lowest found on KAYAK over the last 7 days. Price and availability are not guaranteed.