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$140 Cheap Flights from Phoenix (PHX) to St. Louis (STL)

View $140 flight on Wed, Nov 11, 2026Opens in a new window

Popular airlines from Phoenix Sky Harbor Intl. Airport (PHX) to St. Louis Lambert Intl. Airport (STL)

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

Prices were available within the past 7 days and start at $140 for one-way flights and $188 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Sat, Nov 14 - Mon, Nov 16
PHX
Phoenix
STL
St. Louis
$188 Roundtrip, found 2 days ago
$188
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Sat, Nov 14 from Phoenix to St. Louis, returning Mon, Nov 16, priced at $188 found 2 days ago
Frontier Airlines
Sat, Oct 24 - Wed, Oct 28
PHX
Phoenix
STL
St. Louis
$190 Roundtrip, found 2 days ago
$190
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Sat, Oct 24 from Phoenix to St. Louis, returning Wed, Oct 28, priced at $190 found 2 days ago
Frontier Airlines
Wed, Nov 11 - Fri, Nov 13
PHX
Phoenix
STL
St. Louis
$199 Roundtrip, found 1 day ago
$199
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Wed, Nov 11 from Phoenix to St. Louis, returning Fri, Nov 13, priced at $199 found 1 day ago
Frontier Airlines
Sat, Oct 24 - Sat, Oct 31
PHX
Phoenix
STL
St. Louis
$212 Roundtrip, found 2 days ago
$212
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Sat, Oct 24 from Phoenix to St. Louis, returning Sat, Oct 31, priced at $212 found 2 days ago
Frontier Airlines
Sat, Nov 14 - Mon, Nov 16
PHX
Phoenix
STL
St. Louis
$213 Roundtrip, found 2 days ago
$213
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Sat, Nov 14 from Phoenix to St. Louis, returning Mon, Nov 16, priced at $213 found 2 days ago
Frontier Airlines
Wed, Oct 7 - Wed, Oct 28
PHX
Phoenix
STL
St. Louis
$214 Roundtrip, found 2 days ago
$214
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Wed, Oct 7 from Phoenix to St. Louis, returning Wed, Oct 28, priced at $214 found 2 days ago
Southwest Airlines
Wed, Nov 11 - Sat, Nov 14
PHX
Phoenix
STL
St. Louis
$280 Roundtrip, just found
$280
Roundtrip
just found
Select Southwest Airlines flight, departing Wed, Nov 11 from Phoenix to St. Louis, returning Sat, Nov 14, priced at $280 just found
American Airlines
Wed, Nov 11 - Sat, Nov 14
PHX
Phoenix
STL
St. Louis
$431 Roundtrip, just found
$431
Roundtrip
just found
Select American Airlines flight, departing Wed, Nov 11 from Phoenix to St. Louis, returning Sat, Nov 14, priced at $431 just found
Delta
Wed, Nov 11 - Sat, Nov 14
PHX
Phoenix
STL
St. Louis
$465 Roundtrip, just found
$465
Roundtrip
just found
Select Delta flight, departing Wed, Nov 11 from Phoenix to St. Louis, returning Sat, Nov 14, priced at $465 just found
Alaska Airlines
Wed, Oct 28 - Sat, Oct 31
PHX
Phoenix
STL
St. Louis
$553 Roundtrip, just found
$553
Roundtrip
just found
Select Alaska Airlines flight, departing Wed, Oct 28 from Phoenix to St. Louis, returning Sat, Oct 31, priced at $553 just found

Alternative airports near St. Louis

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Lambert-St. Louis Intl. STL. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $380
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center20 min
Flights from $380

Find the cheapest month to fly from Phoenix (PHX) to St. Louis (STL)

October is typically the cheapest month to fly

From $176 - $343 per traveler.

What you need to know for your flight from Sky Harbor Intl. to Lambert-St. Louis Intl.

Phoenix (PHX) to St. Louis (STL) at a glance

Travelers can choose among several airlines for flights from Phoenix (PHX) to St. Louis (STL) on this domestic short-haul route. Whether you prefer full-service or low-cost carriers, you can compare options to discover the itinerary that suits your budget and schedule while exploring the iconic sights and neighborhoods of St. Louis. Check out the essential details for your flight from Phoenix Sky Harbor International Airport (PHX) to Lambert-St. Louis International Airport (STL).

  • Fastest flight duration: around 3 hours non-stop
  • Route distance: roughly 1,300 miles (2,090 km)
  • Flights per week: around 25+ flights with multiple daily departures on average
  • Typical fares (one-way): economy tickets often range from $70–$395, depending on seasonality and how far ahead you book

Flights from Sky Harbor International Airport (PHX) to Lambert-St. Louis International Airport (STL)

Based on the latest traveler bookings, here are the top airline choices for flights from Phoenix to St. Louis, particularly favored for non-stop and one-stop options. Many travelers opt for layovers at Denver International Airport (DEN, approximately 1h 15m), Harry Reid International Airport (LAS, around 1h 15m), and Dallas-Fort Worth International Airport (DFW, about 1h 15m). This variety allows you to balance price, total travel duration, and cabin class to create the ideal travel experience.

  • Southwest Airlines: This budget-friendly airline provides both non-stop and one-stop flights, with one-way prices usually falling between $95 and $395. It represents around 56% of departures on this route, with a standard non-stop travel duration of 3 hours.
  • American Airlines: A comprehensive carrier with non-stop and one-stop options, American Airlines has one-way fares generally ranging from $100 to $445. It makes up about 26% of the departures for this route, and the typical non-stop flight lasts 3 hours.
  • Frontier Airlines: As a low-cost airline, Frontier offers both non-stop and one-stop services, with one-way fares typically between $70 and $225. This carrier covers roughly 10% of departures on this route, with a usual non-stop travel time of 3 hours.
  • United: This full-service airline provides one-stop flights, with one-way fares generally ranging from $130 to $385. It accounts for approximately 6% of departures along this route, featuring an in-flight duration of 4h 30m and a total journey time of about 5h 45m, including layover time.
  • Delta: Delta, another full-service airline, offers one-stop services with one-way fares typically ranging from $140 to $455. This carrier makes up about 2% of departures on this route, with an in-flight time of 4h 30m and a total travel duration of roughly 5h 45m, including layovers.

Travelers flying from Phoenix to St. Louis can opt for an upgrade, as American Airlines provides first-class service on this route.

Best time to fly from Phoenix (PHX) to St. Louis (STL)

The most popular months for travelers flying from Phoenix to St. Louis are March, April, and October, when peak temperatures in St. Louis reach up to 58.6°F in October. If you prefer quieter travel, consider August, the least busy and relatively cheaper time to visit with fewer crowds and temperatures around 77°F. For better deals, October usually offers the lowest average one-way fare around $166. Flight availability peaks in May and October, with approximately 34 flights per week, making it easier to find convenient departure times. January has the fewest flights, with approximately 20 flights per week.

  • Cheapest time to fly: October usually offers good deals with average one-way fare around $166, roughly 20% cheaper than the yearly average.
  • More budget-friendly months to fly: November and December typically offer average one-way fares of around $177.
  • Most flight options: May and October have the highest number of flights from Phoenix to St. Louis, with approximately 34 flights per week, giving you more flexibility in scheduling your trip.
calendar iconMonthtemperature iconTemperaturecrowd level iconDemandflights iconWeekly Flightsprice iconAverage one-way Fare
January31.6°F (-0.2°C)Average20$215
February34.9°F (1.6°C)Average24$199
March46.4°F (8.0°C)High28$224
April56.1°F (13.4°C)High29$250
May66.6°F (19.2°C)Average34$224
June76.1°F (24.5°C)Low30$248
July78.6°F (25.9°C)Low30$235
August77.0°F (25.0°C)Low24$198
September70.9°F (21.6°C)Average28$188
October58.6°F (14.8°C)High34$166
November46.2°F (7.9°C)Average30$173
December37.8°F (3.2°C)Average30$181

*Average one-way fare is based on Expedia flight booking data from January 2025 to April 2026 for the specified route and travel class and may change depending on availability, dates, and demand.

Alternative routes from Phoenix (PHX) to St. Louis (STL)

  • Phoenix to St. Louis (PHX-SUS): The Spirit of St. Louis Airport (SUS) lies approximately 16 miles from Lambert-St. Louis International Airport (STL), offering convenient access to the city.
  • Phoenix to St. Louis (PHX-CPS): Located about 16 miles from Lambert-St. Louis International Airport (STL), St. Louis Downtown Airport (CPS) provides an alternative route for travelers heading to the area.
  • Mesa to St. Louis (AZA-STL): Phoenix - Mesa Gateway Airport (AZA) is around 22 miles away from Sky Harbor International Airport (PHX), making it a viable option for flights to St. Louis.

How to find the best prices for flights from Phoenix (PHX) to St. Louis (STL)

Getting some of the best deals on flights from Phoenix to St. Louis is all about timing and flexibility. Here are some key tips to help you save:

  1. Best times to book and fly: cheaper fares are typically found when booking 2-8 weeks in advance, which is also when most travelers make their reservations. Afternoon departures between 12 PM and 6 PM tend to be less expensive, even though morning flights from 5 AM to 12 PM are the most popular. Additionally, flying on Monday generally offers cheaper prices, while Friday is the busiest travel day.
  2. Set up price alerts: stay updated on price changes by using Expedia's Price Tracker. Receive alerts when fares drop for your selected route.
  3. Bundle and save: bundle your flight and hotel to save on Expedia, or unlock a hotel deal after booking your flight.*
  4. Compare flight options: use Expedia's search tool to compare airlines, routes, direct vs. non-direct flights, and flight times. You can also sort by price to find the most affordable options.
  5. Stay flexible with dates: being open to different travel days can sometimes help you find better prices on flights and hotels.
  6. Think about luggage: nowadays, it's important to check the airline's baggage policies to find the best value. That may be paying for an additional carry-on bag or booking a ticket with checked luggage included. Either way, double-check your allowance before confirming your booking to avoid excess baggage fees at the airport.

*Members only. Savings vary and are not available on all bundles. Select hotels.

Arriving at Lambert-St. Louis International Airport from Sky Harbor International Airport

St. Louis welcomes travelers from Phoenix with a range of transport options based on price, convenience, and proximity. Here's how to reach St. Louis efficiently:

  • Hotel transfer: Transfers offer a convenient way to reach your hotel in St. Louis, with private rides that can be arranged in advance.
  • Car rental: Renting a car from Lambert-St. Louis International Airport is a great option if you plan to explore and sightsee beyond the city. Browse cheap car rentals at Lambert-St. Louis International Airport on Expedia.
  • Taxi/ride-hailing: Taxis and ride-hailing services may be available from designated pickup areas outside the terminal, check locally on arrival.
  • Public transportation: From Lambert-St. Louis International Airport, Lambert Main Terminal Station, a metro station, is conveniently located just 0.1 miles away on foot, providing easy access to public transportation.

Frequently asked questions

How much does a flight from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) cost?
You can find cheap one-way flights from $140 and cheap return flights from $188 Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) with Expedia. One-way flights generally range between $177 and $906, and roundtrip flights usually range from $338 to $1566. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see the cheapest fares first, and use the Price Tracking tool to receive alerts when Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) ticket fares go up or down.*Typical price ranges based on flights available on Expedia in the last year. Prices include multi-airline options.
What is the cheapest month to fly from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
November is typically the cheapest month to fly from Phoenix, AZ (PHX) to St. Louis, MO (STL), with average round-trip fares around $356. This is about 13% lower than the average price throughout the year, as November often has lower travel demand before the holiday season. Other economical months to consider are September and October.*Averages based on flights available on Expedia in the last year.
Which airlines fly direct from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
2 airlines operate nonstop service from PHX to STL:

  • American Airlines operates around 17 direct flights from PHX to STL every week
  • Frontier Airlines operates around 9 direct flights from PHX to STL every week

What is the cheapest airline that flies from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Frontier Airlines is one of the cheapest airlines offering nonstop flights from Sky Harbor Intl. (PHX) to Lambert-St. Louis Intl. (STL), with round-trip tickets starting from around $390. American Airlines offers one of the cheapest connecting flights from Sky Harbor Intl. (PHX) to Lambert-St. Louis Intl. (STL) with a layover in Dallas-Fort Worth Intl. (DFW) starting from around $585. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.*Prices based on flights available on Expedia in the last year.
How do I find cheap flights from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
To find a cheap flight from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best airline to fly with from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The best airline to fly with from Phoenix, AZ (PHX) to St. Louis, MO (STL) will differ from traveler to traveler. If you like to fly early, WN offers early morning flights. If price is the most important factor, Frontier Airlines typically offers the lowest fares. WN offers the most daily flights from PHX to STL, which is great if flexibility is what you value most. The best carrier for this journey could also be the one you have a loyalty membership with, as flying with that airline or another airline within the same alliance could help you collect points or enjoy lounge access.
What is the best time to fly from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The best time to fly from Phoenix, AZ (PHX) to St. Louis, MO (STL) is in October or November. You can find return flights for about $356 during these months. October is popular for its mild weather and beautiful fall foliage, while November offers a quieter travel experience before the holiday rush.*Prices based on flights available on Expedia in the last year.
How many flights per day from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
There are approximately 7 nonstop flights per day from Sky Harbor Intl. (PHX) to Lambert-St. Louis Intl. (STL). For more options, look at flights that include layovers.
What is the earliest flight from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The earliest flight from Sky Harbor International Airport (PHX) to Lambert-St. Louis International Airport (STL) usually departs at around 12:15 AM, with American Airlines and Southern Airways Express providing this seasonal service. An early flight like this can help you arrive in St. Louis with plenty of time to explore. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What are the most popular departure times for flights from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The most popular departure times for flights from Phoenix (PHX) to St. Louis (STL) are in the early morning, from 6am to 9am. About 26% of passengers prefer this time window. Many major carriers, including United Airlines and Southwest Airlines, offer flights during this window. This timing is favored as it allows you to arrive in St. Louis early and make the most of your day.
How long does it take to fly from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Direct flights from PHX to STL usually take about 3 hours, traveling roughly 1,259 miles. If you opt for a connecting flight, expect to add around 4 hours to your journey. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
First class seats are offered on the PHX to STL route. First class cabins are available on:

  • Delta Air Lines
  • United Airlines
  • American Airlines

How do I earn miles on a Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight with Expedia?
It's easy to earn miles on a Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for St. Louis from Sky Harbor Intl. (PHX)?
From Sky Harbor Intl. (PHX), you can fly into Lambert-St. Louis Intl. (STL) to reach St. Louis. Some flights may connect through major hubs like Harry Reid Intl. (LAS), Portland Intl. (PDX), Denver Intl. (DEN) before reaching St. Louis. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) at the last minute?
Typically, booking a last minute flight from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight and hotel package?
Securing a Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) St Louis Vacation Packages is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
If you booked your Phoenix, AZ (PHX-Sky Harbor Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
Sky Harbor Intl.
Destination airport
Lambert-St. Louis Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Roundtrip price
$188
Distance
1259 mi
Average flight time
4 hours 34 mins

Book with confidence

Phoenix to St. Louis Flights

The cheapest times to fly from Phoenix to St. Louis

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Phoenix to St. Louis are during the month of November. You can find some of the cheapest flights from Phoenix to St. Louis with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Phoenix to St. Louis

Sunday is one of the best days to book for cheap flights from Phoenix to St. Louis: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Phoenix to St. Louis

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Phoenix to St. Louis in 2026. You can also book with separate airlines for your outbound and return journeys, from $140 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Phoenix to St. Louis flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Phoenix to St. Louis airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Phoenix to St. Louis Flights

*Flight schedules are subject to change.

*Available to One Key members.

 

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