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Cheap Flights from St Louis to Phoenix Sky Harbor

Compare St Louis to Phoenix Sky Harbor flight deals

Find the cheapest month or even day of the year to fly to Phoenix Sky Harbor

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Flight deals from St Louis to Phoenix Sky Harbor

Looking for a cheap last-minute deal or the best return flight from St Louis Airport to Phoenix Sky Harbor Airport? If you want to travel next month, return fares start from $422. Find the lowest prices on one-way and return tickets right here.
Phoenix.$422 per passenger.Departing Sat, 18 Jul, returning Sat, 25 Jul.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Sat, 18 Jul, arriving in Phoenix Sky Harbor.Inbound indirect flight with Frontier Airlines, departs from Phoenix Sky Harbor on Sat, 25 Jul, arriving in St Louis.Price includes taxes and charges.From $422, select.
Phoenix.$423 per passenger.Departing Sat, 5 Sep, returning Sat, 19 Sep.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Sat, 5 Sep, arriving in Phoenix Sky Harbor.Inbound indirect flight with Frontier Airlines, departs from Phoenix Sky Harbor on Sat, 19 Sep, arriving in St Louis.Price includes taxes and charges.From $423, select.
Phoenix.$423 per passenger.Departing Tue, 21 Jul, returning Tue, 11 Aug.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Tue, 21 Jul, arriving in Phoenix Sky Harbor.Inbound indirect flight with Frontier Airlines, departs from Phoenix Sky Harbor on Tue, 11 Aug, arriving in St Louis.Price includes taxes and charges.From $423, select.
Phoenix.$423 per passenger.Departing Sat, 1 Aug, returning Sat, 8 Aug.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Sat, 1 Aug, arriving in Phoenix Sky Harbor.Inbound indirect flight with Frontier Airlines, departs from Phoenix Sky Harbor on Sat, 8 Aug, arriving in St Louis.Price includes taxes and charges.From $423, select.
Phoenix.$426 per passenger.Departing Tue, 13 Oct, returning Sat, 17 Oct.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Tue, 13 Oct, arriving in Phoenix Sky Harbor.Inbound indirect flight with Frontier Airlines, departs from Phoenix Sky Harbor on Sat, 17 Oct, arriving in St Louis.Price includes taxes and charges.From $426, select.
Phoenix.$454 per passenger.Departing Thu, 27 Aug, returning Tue, 1 Sep.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Thu, 27 Aug, arriving in Phoenix Sky Harbor.Inbound indirect flight with Frontier Airlines, departs from Phoenix Sky Harbor on Tue, 1 Sep, arriving in St Louis.Price includes taxes and charges.From $454, select.
Phoenix.$496 per passenger.Departing Sun, 1 Nov, returning Wed, 11 Nov.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Sun, 1 Nov, arriving in Phoenix Sky Harbor.Inbound indirect flight with Frontier Airlines, departs from Phoenix Sky Harbor on Wed, 11 Nov, arriving in St Louis.Price includes taxes and charges.From $496, select.
Phoenix.$526 per passenger.Departing Wed, 22 Jul, returning Mon, 27 Jul.Return flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from St Louis on Wed, 22 Jul, arriving in Phoenix Sky Harbor.Inbound direct flight with Southwest Airlines departs from Phoenix Sky Harbor on Mon, 27 Jul, arriving in St Louis.Price includes taxes and charges.From $526, select.
Phoenix.$526 per passenger.Departing Wed, 12 Aug, returning Wed, 19 Aug.Return flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from St Louis on Wed, 12 Aug, arriving in Phoenix Sky Harbor.Inbound direct flight with Southwest Airlines departs from Phoenix Sky Harbor on Wed, 19 Aug, arriving in St Louis.Price includes taxes and charges.From $526, select.
Phoenix.$526 per passenger.Departing Sat, 29 Aug, returning Mon, 7 Sep.Return flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from St Louis on Sat, 29 Aug, arriving in Phoenix Sky Harbor.Inbound direct flight with Southwest Airlines departs from Phoenix Sky Harbor on Mon, 7 Sep, arriving in St Louis.Price includes taxes and charges.From $526, select.
Phoenix.$532 per passenger.Departing Wed, 28 Oct, returning Sun, 1 Nov.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Wed, 28 Oct, arriving in Phoenix Sky Harbor.Inbound indirect flight with Frontier Airlines, departs from Phoenix Sky Harbor on Sun, 1 Nov, arriving in St Louis.Price includes taxes and charges.From $532, select.
Phoenix.$596 per passenger.Departing Tue, 30 Jun, returning Sat, 4 Jul.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Tue, 30 Jun, arriving in Phoenix Sky Harbor.Inbound indirect flight with Frontier Airlines, departs from Phoenix Sky Harbor on Sat, 4 Jul, arriving in St Louis.Price includes taxes and charges.From $596, select.
Phoenix.$597 per passenger.Departing Tue, 21 Jul, returning Tue, 11 Aug.Return flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from St Louis on Tue, 21 Jul, arriving in Phoenix Sky Harbor.Inbound direct flight with Southwest Airlines departs from Phoenix Sky Harbor on Tue, 11 Aug, arriving in St Louis.Price includes taxes and charges.From $597, select.
Phoenix.$601 per passenger.Departing Tue, 13 Oct, returning Sat, 17 Oct.Return flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from St Louis on Tue, 13 Oct, arriving in Phoenix Sky Harbor.Inbound direct flight with Southwest Airlines departs from Phoenix Sky Harbor on Sat, 17 Oct, arriving in St Louis.Price includes taxes and charges.From $601, select.
Phoenix.$603 per passenger.Departing Wed, 9 Dec, returning Wed, 16 Dec.Return flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from St Louis on Wed, 9 Dec, arriving in Phoenix Sky Harbor.Inbound direct flight with Southwest Airlines departs from Phoenix Sky Harbor on Wed, 16 Dec, arriving in St Louis.Price includes taxes and charges.From $603, select.
Phoenix.$629 per passenger.Departing Thu, 29 Oct, returning Mon, 2 Nov.Return flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from St Louis on Thu, 29 Oct, arriving in Phoenix Sky Harbor.Inbound direct flight with Southwest Airlines departs from Phoenix Sky Harbor on Mon, 2 Nov, arriving in St Louis.Price includes taxes and charges.From $629, select.

Find the cheapest month to fly from St Louis to Phoenix Sky Harbor

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like St Louis to Phoenix Sky Harbor flights are currently cheapest in July.
Jun
Find prices
Jul
from $422
Aug
from $423
Sep
from $423
Oct
from $426
Nov
from $496
Dec
from $603
Jan
from $748
Feb
from $701
Mar
from $860
Apr
Find prices
May
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Direct flights from St Louis to Phoenix Sky Harbor

St Louis to Phoenix Sky Harbor: Alternative routes

Compare routes from St Louis to Phoenix below. You may find an airport to fly into that's cheaper, faster, or easier than Phoenix Sky Harbor.

Phoenix Sky Harbor

6km from central Phoenix
ClosestCheapest
from $422
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Phoenix Scottsdale Municipal

24km from central Phoenix
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Phoenix-Deer Valley

27km from central Phoenix
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Phoenix-Mesa Gateway

42km from central Phoenix
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St Louis to Phoenix: Flight information

The things to know before you go.
Cheapest flight found$422
Cheapest month to flyJuly
Average flight time3 hrs, 22 mins
Most popular airlineSouthwest Airlines
Average flights per week65

Finding cheap flights from St Louis to Phoenix Sky Harbor: Frequently asked questions

The best price we found for a return flight from St Louis to Phoenix Sky Harbor is $422. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
3 hours and 22 minutes is the average flight time from St Louis to Phoenix Sky Harbor.
Southwest Airlines, American Airlines and Alaska Airlines fly direct from St Louis to Phoenix Sky Harbor.
As of June 2026, there are 65 flights per week flying from St Louis to Phoenix Sky Harbor.
The cheapest month to fly from St Louis to Phoenix Sky Harbor is usually July.
After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from St Louis Airport to Phoenix Sky Harbor Airport on Saturday, 18 July 2026.
Yes – the average flight time is 3 hours and 22 minutes.
We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to Phoenix Sky Harbor but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.

We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to Phoenix is around 40 days in advance, so don’t leave your flight to the last minute.

Currently, Frontier Airlines and Southwest Airlines offer the cheapest flight tickets to Phoenix Sky Harbor.

Flying from St Louis Airport (STL) to Phoenix Sky Harbour Airport (PHX): what you need to know

  • The average time for a direct flight from St Louis Airport to Phoenix Sky Harbour Airport is 3 hours 20 minutes.

  • Phoenix's timezone is UTC-7, which makes Phoenix one hour behind St Louis.

  • Every week, there are 31 St Louis Airport to Phoenix Sky Harbour Airport flights.

  • Arriving two hours before an international flight and one hour ahead of a domestic departure are golden rules for hassle-free flying. Make sure you're at the airport on time to board your STL to PHX flight.

  • Travelling during a peak time such as July? Major public holidays and other popular seasons can lead to longer lines and delays at security. Be extra cautious and arrive up to four hours before international flights and two hours before a domestic departure.

  • With direct flights from St Louis Airport to Phoenix Sky Harbour Airport available through a range of airlines, getting to Phoenix (and then other corners of the United States) is a snap. You can travel nonstop with these carriers:

  • Southwest Airlines has the highest passenger demand on this route.

  • With an impressive 87.5% of services arriving as scheduled, Frontier Airlines is the most punctual carrier for STL to PHX flights.

  • We make it a piece of cake to book a flight with a stopover. To see all your options for tickets from St Louis Airport to Phoenix Sky Harbour Airport, uncheck 'Direct flights only.' Then, choose a flight with a stop long enough to explore your chosen city. Top stopovers between STL and PHX include:

    • Denver International Airport

    • Austin-Bergstrom Airport

    • Kansas City International Airport

How to find the cheapest flights from St Louis Airport (STL) to Phoenix Sky Harbour Airport (PHX)

  • The cheapest price we've seen for a one-way St Louis Airport to Phoenix Sky Harbour Airport flight is $155. A round-trip ticket is currently $422. Depending on the availability and when you book, these fares can change.

  • To pick up cheap tickets from STL to PHX, book in advance. Airlines usually offer lower prices when flights are first released.

  • May is the cheapest month for flights from St Louis Airport to Phoenix Sky Harbour Airport. If you're looking to travel at a different time of year, the 'Whole month' tool will show you the lowest prices for each month.

  • You won't have to check back in every day to see if fares have dropped when you set up a Price Alert. We'll let you know as soon as there's a change in price on cheap flights from STL to PHX.

  • Tailor your trip with filters. Pick your departure and arrival times, total journey duration and airlines. You can also sort results by 'Cheapest,' 'Best' or 'Fastest' flights from St Louis Airport to Phoenix Sky Harbour Airport.

Handy information about St Louis Airport (STL)

Arriving at Phoenix Sky Harbour Airport (PHX)

When to fly to Phoenix Sky Harbour Airport (PHX)

  • It's time to plan your dates for your flight from St Louis Airport to Phoenix Sky Harbour Airport. April is the most popular month to visit Phoenix. If you want a more relaxed vibe, go in March.

  • The warmest month in Phoenix is July, with temperatures ranging between 27ºC and 45ºC. Lock in your flights from St Louis Airport to Phoenix Sky Harbour Airport in this month if this is the type of weather you like.

  • January has average temperatures of between 4ºC and 21ºC. Look for cheap tickets from STL to PHX around that time if you want to travel in cooler conditions.

Explore more of the United States

  • San Diego is just one of the many cities in the United States waiting to be discovered once you've seen Phoenix. Around 483 kilometres away to the west, its top attractions include San Diego Zoo, San Diego Balboa Park and USS Midway Museum.

  • Around 418 kilometres north-west of Phoenix, Las Vegas is another essential stop in the United States. No visit is complete without checking out Ciudad del Pecado o Las Vegas, Las Vegas Strip and Fountains of Bellagio.

Plan the rest of your trip from St Louis to Phoenix

Prices shown on this page are estimated lowest prices only. Found in the last 12 days.