$70 Find Cheap Flights from Philadelphia to St. Charles - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Philadelphia to St. Charles departing on 10/31. 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.
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1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$131
Typical prices: $248-$450
Frontier
Mon 8/31Mon 9/7
PHL - STL • 1 stop
Cheapest non-stop
$277
Typical prices: $269-$463
American Airlines
Thu 8/20Mon 8/24
PHL - STL • Non-stop
Arrival airport
You can't fly directly to St. Charles. It is served by St. Louis (STL), located 7.2 miles from St. Charles.
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Flight Deals
Useful Info
Flight Deals

Cheap Flights from Philadelphia to St. Charles (PHL-STL)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Philadelphia to St. Charles 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 Philadelphia to St. Charles

Mon, Aug 31 - Mon, Sep 7
Frontier Logo
8:30 am - 5:22 pm
PHL
-
STL
9h 52m
1 stop
Frontier Logo
6:17 pm - 7:15 am
STL
-
PHL
11h 58m
1 stop
$131Frontier
Tue, Nov 3 - Fri, Nov 6
Frontier Logo
5:28 pm - 9:40 am
PHL
-
STL
17h 12m
1 stop
Frontier Logo
10:35 am - 6:15 pm
STL
-
PHL
6h 40m
1 stop
$144Frontier
Thu, Sep 3 - Mon, Sep 7
Frontier Logo
8:30 am - 5:22 pm
PHL
-
STL
9h 52m
1 stop
Frontier Logo
6:17 pm - 7:15 am
STL
-
PHL
11h 58m
1 stop
$147Frontier
Wed, Sep 23 - Sat, Sep 26
Multiple Airlines Logo
8:41 am - 1:10 pm
PHL
-
STL
5h 29m
1 stop
Multiple Airlines Logo
8:10 pm - 5:20 pm
STL
-
PHL
20h 10m
2 stops
$243Multiple Airlines
Thu, Sep 24 - Sun, Sep 27
Multiple Airlines Logo
5:32 pm - 1:10 pm
PHL
-
STL
20h 38m
1 stop
Multiple Airlines Logo
2:00 pm - 1:07 am
STL
-
PHL
10h 07m
2 stops
$255Multiple Airlines
Thu, Sep 24 - Sun, Sep 27
Multiple Airlines Logo
12:40 pm - 1:10 pm
PHL
-
STL
25h 30m
1 stop
Multiple Airlines Logo
2:00 pm - 1:07 am
STL
-
PHL
10h 07m
2 stops
$257Multiple Airlines
Thu, Aug 20 - Mon, Aug 24
American Airlines Logo
10:01 pm - 11:34 pm
PHL
-
STL
2h 33mnonstop
American Airlines Logo
6:00 am - 9:22 am
STL
-
PHL
2h 22mnonstop
$277American Airlines
Thu, Aug 20 - Thu, Aug 20
American Airlines Logo
9:18 am - 10:52 am
PHL
-
STL
2h 34mnonstop
American Airlines Logo
5:42 pm - 9:03 pm
STL
-
PHL
2h 21mnonstop
$277American Airlines
Sat, Sep 5 - Tue, Sep 8
Southwest Logo
11:55 am - 1:15 pm
PHL
-
STL
2h 20mnonstop
Southwest Logo
6:40 pm - 9:55 pm
STL
-
PHL
2h 15mnonstop
$277Southwest
Mon, Aug 17 - Mon, Aug 17
Southwest Logo
6:20 am - 7:35 am
PHL
-
STL
2h 15mnonstop
Southwest Logo
7:05 pm - 10:15 pm
STL
-
PHL
2h 10mnonstop
$277Southwest
Useful Info

Good to know

Low season

February

Cheapest flight

$70
Best time to beat the crowds but there is an average 7% increase in price.
Most popular time to fly and prices are also 3% lower on average.
Flight from Philadelphia to St. Louis

When to book flights from Philadelphia to St. Charles

Are your dates flexible? Find out the best times to travel from Philadelphia to St. Charles based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

FAQs for booking flights from Philadelphia to St. Charles

  • Which airports will I be using when flying from Philadelphia to St. Charles?

    When flying out of Philadelphia you’ll be using Philadelphia. St. Charles does not have its own airport so you’ll be flying into nearby Lambert-St Louis airport, which is 7.2 mi away.

  • How long does a flight from Philadelphia to St. Charles take?

    Direct flights cover the 811 miles separating Philadelphia and St. Charles in about 2h 15m.

  • How many flights are there between Philadelphia and St. Charles?

    8 direct flights run between Philadelphia and St. Charles on a daily basis. On average, there are about 62 departures each week.

  • What’s the cheapest day of the week to fly between Philadelphia and St. Charles?

    Consider leaving on a Friday and avoid Saturdays if you are looking for the best rates. For your return to Philadelphia, you’ll find the best rates on Mondays and the most expensive ones on Saturdays.

  • How does KAYAK find such low prices on flights from Philadelphia to St. Charles?

    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 Philadelphia to St. Charles.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Charles from Philadelphia 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 Philadelphia to St. Charles?

    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. Charles with an airline and back to Philadelphia with another airline.

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

    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. Charles from Philadelphia up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from Philadelphia to St. Charles?

    In the last 5 days, the cheapest one-way ticket between Philadelphia and St. Charles found on KAYAK was with Frontier for $70. Frontier offered a round-trip connection from $144 and American Airlines from $248.

Top tips for finding cheap flights from Philadelphia to St. Charles

  • There is no airport in St. Charles. Instead, you’ll be flying into St. Louis Lambert Airport when flying between Philadelphia and St. Charles.
  • The cheapest flight from Philadelphia to St. Charles was found 70 days before departure, on average.
  • Book at least 1 week before departure in order to get a below-average price.
  • High season is considered to be May, June and July. The cheapest month to fly is September.

Reviews of the top 3 airlines serving Philadelphia to St. Charles

 
Need help choosing which airline to fly with from Philadelphia to St. Charles? 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 4226 reviews
7.5Entertainment
8.1Boarding
8.0Comfort
8.6Crew
7.0Food
Airline reviews

My experience will Southwest was good. I wish there was more entertainment and the boarding process was slow at time but other than that my experience was great definitely will be flying with SouthWest again.

8.0 ExcellentAnonymous, Jul 2026
PHL - BNA
Read more Southwest reviews

My experience will Southwest was good. I wish there was more entertainment and the boarding process was slow at time but other than that my experience was great definitely will be flying with SouthWest again.

Great job! My family doesnt fly often but we felt safe 100%

Communication about the delayed flight was poor. We were told to move gates three times but that was bad information. We went from gate 128 to gate 126 and then to gate 123 and back to gate 126. Communication about the delay was bad. Ended up being 1 1/2 hour late getting home.

I have roller bag with food and medication told me I couldn't bring on my 2nd flight today. 15 years flying with SW never an issue with that bag.

I have not flown Southwest in awhile and had a very pleasant experience. From ticketing to boarding to the flight. The flight left on time and landed ahead of schedule. It won't be so long next time!!

Everything went smoothly and we even arrived a little bit early.

Boarded on time but once we were ready for take off, the crew determined that, although every seat was taken, somehow someone was on the wrong flight. Delay, delay delay, announcements and ended up with one person checking EVERY ID against their passenger Manifest only to figure out it was a "clerical error." We departed 54 minutes late causing me to run in the St. Louis Airport to make my connection and lose the priority boarding spot I had paid for. Unnecessary delay.

Flight was delayed due to plane not passing inspection And one of the crew had to time out and we had to wait for another one A 3 hour delay

For my birthday trip this was my second time ever flying, this trip was the best.

We boarded the flight and set two and a half hours on the jetway. Would have been better if they had not boarded us at all. Plane was hot and it was limited ability to access the restrooms or get a drink of water. Very unpleasant experience

Very good, boarded and took off on time and landed early

Boarding and Delays The boarding process for my American Airlines flight from Copenhagen to Philadelphia was a bit tricky. We experienced a gate change that required a long walk to a new area of the airport. Additionally, boarding was not via a jet bridge; we had to take a shuttle bus to the plane and then carry our luggage up the stairs ourselves. Furthermore, the bag drop didn't open until about 12:20 PM, which was only three hours before our scheduled departure. This meant I couldn't drop my bag off early and had to wait outside of security in order to drop off my bag and use the kiosk. The bag drop self-service kiosks also didn't open until about 12:00 PM when an American Airlines employee unlocked them so that we could print out our boarding passes and bag tags, which further created a backlog. The flight was delayed by over an hour because we had to wait for one of the tires on the plane to be changed. Flight Attendant Professionalism On a positive note, the flight attendant was very professional when handling a passenger who was sitting in the wrong seat. Even though the passenger was persistent and reluctant to move, the flight attendant calmly ensured the assigned passenger could take their seat. Kudos to the flight attendant for keeping his calm and composure, not allowing the issue to escalate, and handling it well under pressure while a line of passengers waited in the aisle to board. In-Flight Service The in-flight service was also fast, prompt, and efficient, although service had to be suspended for the last two hours of the flight due to weather and turbulence, which was outside of the crew's control. Limited Flight Options Please note that American Airlines only operates one flight per day in and out of Copenhagen. This means there are limited options available if your flight is delayed or canceled, which is something to take into consideration when booking.

Quick flight again no one illness why there were multiple delays and changing of the gate number.

Fine. Nothing to write home about. The plane left on time, and arrived on time.

Flight left early and arrived 30 MINUTES early at the destination. Smooth trip.

Flight was 3 hours delayed. They gave our plan to two other routes. Need to knock that off.

The flight was on time and the landing was very smooth. The crew and flight attendants were all very friendly and professional.

Plane was super cold. No entertainment unless you were with mileage program Getting off the plane was super slow

I appreciate that I finally got the seat I paid extra for this time. Thank you

This flight captain and crew were amazing, started ahead of time of departure and reached 30 mins before arrival time. Amazing!

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.

Terrible. Flight cancelled with no reasoning and no flights to rebook. Employees were useless and did nothing to help. Did not even know where to retrieve luggage from the cancelled flight. Flyers beware.

sluggish boarding and arrival procedures, fake nice flight attendants, and lots of delays.

You get what you pay for nothing essentially but a hard uncomfortable seat that doesn’t recline and kids screaming all around you and chaotic boarding and limited check bag weight allowance when compared to other airlines

Not very good. Paid in excess of $400 for assigned seating for my family and that was not provided. I want that money back.

Check in at Philadelphia international was absolutely terrible! I fly 2 to 3 times a month and avoid frontier at all cost and will never fly Frontier again! The night before travel, I tried checking in however, the app was giving me an error, so I went to the desktop, which instructed you that you need to use the app. The next day I presented at the check-in gate after trying at least a half dozen times prior to getting into the airport and continuing to getting the error in the app. I actually had rebooted my phone numerous times and reinstall the app just in case. My phone is only one generation older than the current model. It has no problems completing a frontier flight purchase or any other app issues. There was only three frontier employees working at check-in and a huge line while I was in line I continued to try and check in via the app. As I approach the desk, I was dreading dealing with the agent. He was extremely unprofessional, anti-semantic & very ignorant, and mean to the people in front of me, as well as the people who ended up being behind me. He literally told people “Man I don’t care bout y’all” in his native dialect! Maintaining my composure I approached and explained the situation. To which he replied, you’re gonna have to pay then! I don’t understand. It’s an issue with their app not allowing me to check in! Not my issue! He told me if I pay cash it would be $15, $25 if I pay credit card. I don’t understand a $10 difference for paying with a credit card? I am completely cashless so I continued to try using the app to avoid the $25 fee, Which I still don’t believe that I should be responsible for since it was Frontier’s technical issue!!! I continued to check in via the app a couple more times after he verified I was doing everything right he proceeded to continue to belittle the people behind me. Yelling at them saying I don’t care about you people! I cannot believe that this is the way that businesses would treat its customers! Unfortunately, the black mail with dreadlocks did not have a name tag all he had was a frontier sweater on! For the $25 fee that I ended up getting charged on my credit card. I should’ve just booked originally with Spirit or any other carrier! I have no problem paying fees that I should be responsible for, but when it’s due to a technical failure of a company, the customer should not be responsible for it! I cannot believe that it’s not frontier going out of business!

terrible cascading delays and unhelpful customer service. uncomfortable plane. crew was great, however!

Booked direct in July '24. Turned into a 14 hr layover (both ways) in Denver. My 5 day vaca turned into a 1 day . Not good, BUT,... Thank you for the people @ Frontier who were professionally friendly & approachable.

$80 fee for a backpack as a personal item is robbery.

Flying Frontiier was extremely poor!! I paid for a7:15am flight on flight 1601 from PHL To Las Vegas and the delay was brutally, excruciatingly and disgustingly long (8 hrs). I arrived by Uber to PHL at 5:30 am and had to spend the entire 8 hr delay inside the airport. Even more atrocious was that the flight was delayed twice. On the phone with customer service for two hours and was not fully compensated. I feel taken advantage of with this airline. They offered a menial couched for another flight within 90 days to me and my husband who has never flown but this experience has made us almost 100% sure to not fly this airline and will suggest that others don’t either. We don’t want to book ever again, don’t want a menial voucher and I believe by standard and because the flight was delayed for 8 hours, I should be fully reimbursed for the entire round trip. There is no excuse why this should have ever occurred. After sharing my experience with others in Vegas and Philadelphia, I was told that Frontier airlines is notorious for long delayed flights, poor customer service and refusal to compensate people correctly. I’m very nervous to see what departing from Vegas to Philadelphia will bring.

Everything you need to know for your flight from Philadelphia to St. Charles

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