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St. Charles

$81+ Cheap flights from Sky Harbor Intl (PHX) to St. Charles, MO

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/29. Fares are subject to change and may not be available on all flights or dates of travel.
PHX — STL
Aug 5 — Aug 121
Tue 8/5
Tue 8/12
1 adult, Economy
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Cheapflights Tip: The best prices from Phoenix Sky Harbor Intl to St. Charles are usually found in September or August, booked 87 days in advance, depart on a Tuesday or Friday and return on a Wednesday

Cheap flight deals from Sky Harbor Intl to St. Charles

Keep the following information in mind while searching for Sky Harbor Intl to St. Charles flight deals. Data was last updated July 31, 2025.

Round-trip from

$237
(CheapOair)

One-way from

$81
(Southwest)

Popular in

January

Cheapest in

September

Average price

$373
From Phoenix Sky Harbor Intl to St. Charles
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One-way flight from Phoenix Sky Harbor Intl to St. Charles
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Highest demand for flights based on searches. 9% potential increase in price ($38 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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Find flight deals from Sky Harbor Intl to St. Charles

Cheapest flights from Sky Harbor Intl to St. Charles
Explore the most affordable flight options available from Sky Harbor Intl to St. Charles. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.

This CheapOair deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/2110:42 pmPHX - STL
1 stop12h 50mSpirit Airlines
Mon 8/252:30 pmSTL - PHX
1 stop9h 07mSpirit Airlines
Deal found 7/29$237
This FlightHub deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/128:15 amPHX - STL
1 stop10h 25mMultiple Airlines
Sun 9/1412:05 pmSTL - PHX
1 stop11h 59mMultiple Airlines
Deal found 7/29$241
This Delta deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/235:15 pmPHX - STL
1 stop5h 09mDelta
Sat 10/256:00 amSTL - PHX
1 stop6h 40mDelta
Deal found 7/31$244
This Sun Country Air deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Sun Country Air is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/186:02 pmPHX - STL
1 stop15h 25mSun Country Air
Sun 9/217:34 amSTL - PHX
1 stop27h 18mSun Country Air
Deal found 7/31$245
This American Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/2812:25 pmPHX - STL
Nonstop3h 05mAmerican Airlines
Thu 9/48:00 amSTL - PHX
Nonstop3h 29mAmerican Airlines
Deal found 7/31$246
This Southwest deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/186:30 pmPHX - STL
Nonstop2h 55mSouthwest
Tue 9/2310:25 amSTL - PHX
1 stop6h 25mSouthwest
Deal found 7/29$256
This Trip.com deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/712:09 pmPHX - STL
1 stop18h 58mFrontier
Fri 10/102:54 pmSTL - PHX
Nonstop3h 22mFrontier
Deal found 7/31$263

Cheapflights Fare Finder

 
Customize your flight search to find flights from Sky Harbor Intl to St. Charles 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, Cheapflights users made 2,558,603 searches. Data last updated July 31, 2025.
Use the filters below to find and compare flights from Phoenix Sky Harbor Intl Airport to St. Charles that are best for you.

Fly from

Sky Harbor Intl

Fly to

St. Charles

Route

Depart

Return

Price

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Thu 8/21

10:42 pm-1:32 pm

1 stop12h 50m

Lambert-St Louis

Mon 8/25

2:30 pm-9:37 pm

1 stop9h 07m

$237

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Fri 9/12

8:15 am-8:40 pm

1 stop10h 25m

Lambert-St Louis

Sun 9/14

12:05 pm-10:04 pm

1 stop11h 59m

$241

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Thu 10/23

5:15 pm-12:24 am

1 stop5h 09m

Lambert-St Louis

Sat 10/25

6:00 am-10:40 am

1 stop6h 40m

$244

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Thu 9/18

6:02 pm-11:27 am

1 stop15h 25m

Lambert-St Louis

Sun 9/21

7:34 am-8:52 am

1 stop27h 18m

$245

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Thu 8/28

12:25 pm-5:30 pm

Nonstop3h 05m

Lambert-St Louis

Thu 9/4

8:00 am-9:29 am

Nonstop3h 29m

$246

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Thu 9/18

6:30 pm-11:25 pm

Nonstop2h 55m

Lambert-St Louis

Tue 9/23

10:25 am-2:50 pm

1 stop6h 25m

$256

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Tue 10/7

12:09 pm-9:07 am

1 stop18h 58m

Lambert-St Louis

Fri 10/10

2:54 pm-4:16 pm

Nonstop3h 22m

$263

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Wed 8/27

6:10 am-2:26 pm

1 stop6h 16m

Lambert-St Louis

Fri 9/5

4:40 pm-8:17 pm

1 stop5h 37m

$292

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Wed 10/29

5:10 am-10:00 am

Nonstop2h 50m

$81

PhoenixSt. Louis

PHX - STL

PHXSTL

Phoenix Sky Harbor Intl

Mon 10/27

8:00 am-12:59 pm

Nonstop2h 59m

$93

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/31

Showing 1-10 of 17 results
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Best time to book a flight from Sky Harbor Intl to St. Charles

Have a flexible travel schedule? Discover the best time to fly to St. Charles from Sky Harbor Intl with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Phoenix Sky Harbor Intl Airport to St. Charles

How far ahead should I book a flight from Phoenix Sky Harbor Intl Airport to St. Charles?

Use this chart to determine the optimal time to book a round-trip flight from Sky Harbor Intl to St. Charles. Price data was last updated on July 25, 2025.

The price you pay for your flight from Phoenix Sky Harbor Intl Airport to St. Charles may vary depending on when you book. For the best chance of a lower fare, look to book 87 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Phoenix Sky Harbor Intl Airport to St. Charles?

Currently, August is the cheapest month in which you can book a flight from Phoenix Sky Harbor Intl Airport to St. Charles (average of $311). Flying from Phoenix Sky Harbor Intl Airport to St. Charles in March is currently the most expensive (average of $356). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from PHX to CH5?

Find hourly flight availability from Sky Harbor Intl to St. Charles. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 31, 2025.

When flying from Phoenix Sky Harbor Intl Airport to St. Charles, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

What is the cheapest day to fly from Phoenix Sky Harbor Intl Airport to St. Charles?

Use this chart to determine the cheapest time to fly round-trip from Sky Harbor Intl to St. Charles. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Phoenix Sky Harbor Intl Airport to St. Charles flight should consider departing on Tuesday afternoons when fares are most often at their lowest. Sunday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

How much does it cost to fly round-trip from Phoenix Sky Harbor Intl Airport to St. Charles?

Reviews of airlines servicing St. Charles

Get insights into the airlines that provide service to St. Charles. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Charles. Reviews last updated July 31, 2025.
Read reviews from past customers who have flown Alaska Airlines, Southwest, and Delta from Phoenix Sky Harbor Intl Airport to St. Charles. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Southwest
8.0
Very good
4,246 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Delta
8.0
Very good
7,981 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
United Airlines
7.4
Good
8,900 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Related info for your journey

Find useful and relevant information for your journey from Sky Harbor Intl to St. Charles. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What are the cheapest airlines to fly from Phoenix Sky Harbor Intl Airport to St. Charles one-way?

    The cheapest airline one-way is Southwest, with whom users have recently found tickets for as low as $81. However, be on the lookout for offers from Frontier and Spirit Airlines, as they are both options that can get you from Phoenix Sky Harbor Intl Airport to St. Charles for a low price.

  • What are the most reliable airlines from Phoenix Sky Harbor Intl Airport to St. Charles?

    No one likes to see their flight delayed. When booking a flight from Phoenix Sky Harbor Intl Airport to St. Charles consider choosing SkyWest Airlines (93%), Alaska Airlines (90%) or American Airlines (89%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Phoenix Sky Harbor Intl Airport to St. Charles?

    While on average a flight from Phoenix Sky Harbor Intl Airport to St. Charles is generally $310, our data shows the cheapest flight currently is $123. When looking at the most popular route, (Phoenix Sky Harbor Intl - Lambert-St Louis), you can expect to pay $175 for that flight.

  • Can I find deals for flights from Sky Harbor Intl to St. Charles that include hotel bookings?

    Yes. In addition to deals on Sky Harbor Intl to St. Charles flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Sky Harbor Intl to St. Charles?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Sky Harbor Intl to St. Charles.

  • Can I find deals for business class flights from Sky Harbor Intl to St. Charles?

    Yes. Cheapflights offers flight deals from Sky Harbor Intl to St. Charles by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Phoenix Sky Harbor Intl Airport to St. Charles?

    Currently, August is the cheapest month in which you can book a flight from Phoenix Sky Harbor Intl Airport to St. Charles (average of $311). Flying from Phoenix Sky Harbor Intl Airport to St. Charles in March is currently the most expensive (average of $356). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

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Top 5 airlines flying from Sky Harbor Intl to St. Charles

Discover the top 5 airlines that operate flights from Sky Harbor Intl to St. Charles. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated July 31, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$116Average$220FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$207Average$478FlexibilityNo cancel feeOn-time71%
DeltaCheapest$236Average$336FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$263Average$395FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$299Average$415FlexibilityNo cancel feeOn-time63%

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