$77 Find Cheap Flights from Philadelphia to St. Charles

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 5/12. 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

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Everything you should know

Cheapest round-trip
$318
Overall average: $485
American Airlines
Mon 5/11Sat 5/16
PHL - STL • Non-stop
Cheapest one-way
$77
Typical prices: $171-$359
Frontier
Tue 5/12
PHL - STL • 1 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, May 11 - Sat, May 16
American Airlines Logo
5:44 pm - 7:31 pm
PHL
-
STL
2h 47mnonstop
American Airlines Logo
6:29 am - 9:45 am
STL
-
PHL
2h 16mnonstop
$318American Airlines
Thu, Apr 2 - Sat, Apr 11
United Airlines Logo
11:36 am - 3:48 pm
PHL
-
STL
5h 12m
1 stop
United Airlines Logo
11:15 am - 5:32 pm
STL
-
PHL
5h 17m
1 stop
$319United Airlines
Tue, Mar 31 - Sat, Apr 4
Frontier Logo
5:05 am - 10:32 am
PHL
-
STL
6h 27m
1 stop
Frontier Logo
8:16 pm - 5:34 am
STL
-
PHL
8h 18m
1 stop
$320Frontier
Fri, May 8 - Sun, May 10
Frontier Logo
8:35 pm - 8:55 am
PHL
-
STL
13h 20m
2 stops
Frontier Logo
4:19 pm - 12:40 am
STL
-
PHL
7h 21m
1 stop
$322Frontier
Tue, Apr 7 - Fri, Apr 10
Southwest Logo
6:35 pm - 8:00 pm
PHL
-
STL
2h 25mnonstop
Southwest Logo
1:35 pm - 4:45 pm
STL
-
PHL
2h 10mnonstop
$324Southwest
Wed, Mar 25 - Mon, Mar 30
Frontier Logo
9:50 pm - 7:17 am
PHL
-
STL
10h 27m
1 stop
Frontier Logo
8:12 pm - 5:31 am
STL
-
PHL
8h 19m
1 stop
$325Frontier
Sun, May 10 - Sun, May 17
Frontier Logo
10:39 am - 6:50 am
PHL
-
STL
21h 11m
2 stops
Frontier Logo
11:21 am - 8:10 am
STL
-
PHL
19h 49m
1 stop
$326Frontier
Thu, May 14 - Mon, May 18
American Airlines Logo
5:44 pm - 7:31 pm
PHL
-
STL
2h 47mnonstop
American Airlines Logo
6:29 am - 9:45 am
STL
-
PHL
2h 16mnonstop
$327American Airlines
Sat, Apr 4 - Tue, Apr 14
Delta Logo
6:05 am - 9:46 am
PHL
-
STL
4h 41m
1 stop
Delta Logo
5:59 pm - 10:50 pm
STL
-
PHL
3h 51m
1 stop
$328Delta
Mon, Apr 13 - Mon, Apr 20
Southwest Logo
2:15 pm - 10:40 pm
PHL
-
STL
9h 25m
2 stops
Southwest Logo
2:15 pm - 11:45 pm
STL
-
PHL
8h 30m
2 stops
$329Southwest
Useful Info

Good to know

Low seasonFebruary
Cheapest flight$77
Best time to beat the crowds but there is an average 7% increase in price.
Most popular time to fly with an average 20% increase in price.
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 25m.

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

    14 direct flights run between Philadelphia and St. Charles on a daily basis. On average, there are about 102 departures each week.

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

    Consider leaving on a Saturday and avoid Wednesdays if you are looking for the best rates. For your return to Philadelphia, you’ll find the best rates on Wednesdays 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 72 hours, the cheapest one-way ticket between Philadelphia and St. Charles found on KAYAK was with Frontier for $70. Spirit Airlines offered a round-trip connection from $93 and Frontier from $135.

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 58 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 April, May and June. The cheapest month to fly is September.

Reviews of the top 5 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 4317 reviews
8.0Comfort
8.6Crew
7.5Entertainment
8.1Boarding
7.0Food
Airline reviews

Long layover between flights to Long Island from BWI - need better coordination between flights

4.0 OkayKenny, Mar 2026
TPA - BWI
Read more Southwest reviews

Long layover between flights to Long Island from BWI - need better coordination between flights

I elected to pay for the upgrades and found very little difference

The new seating arrangement is so over priced for what you get.

The problem with the seat assignments is that there were a lot of rows in the front that were empty but my row at the back was full. Just not so pleasant.

No food or entertainment, just a quick 40 minute flight. A little bumpy due to Santa Ana winds but pilot has no control over that. Good flight and landing!

Good but I prefer choose your own seat. With the new assigned seats they should board from the back I see no advantage to this new boarding. Just like every other airline

I realize they are still working out kinks with the new boarding process, but by the time I boarded in group 5, most of the bins were full. All airlines should better enforce small bags and jackets going under the seats until everyone has boarded.

WiFi was not working and didn’t have a beverage service

Snacks are always pretzels. Why can't you also offer peanuts ?

Flight boarded late after announcing on time boarding. Flight arrived only a little late despite late departure. Had trouble connecting to WiFi

We landed and sat on the tarmac for 45 minutes because they only have one gate at the airport and there was another plane running late so we had to wait

The WiFi was not working. That made for a long flight.

Absolutely no communication on why there's a delay and multiple flight time reschedules. I would have canceled the flight and drove back home if I known it was going to be rescheduled 3 or 4 times.

Another late night flight and MORE men belligerently drinking and yelling. I had to move from first to economy because they were so obnoxious and disruptive. Crazy to go from a cozy chair to cardboard when you were supposed to be in first. Delta allows was too much drinking which leads to belligerent behavior.

I was in first class and literally the men behind me were so aggressively loud I moved myself to economy. This has become so common on Delta - people using audio without headphones, and men on 12am / late night flights drinking and yelling to talk to each other which prevents anyone around them from resting. Pretty crazy to have to move from first to economy (poorer service, less comfort...). Wild wild. Looking into other airlines.

Love delta smaller commuter plane so no entertainment and paid wifi on MKE-LGA leg was extremely unreliable and slow

Stop changing gates. Stop cancelling flights Stop moving my seat.

Extremely disappointed with Delta. They canceled flight last minute and then I rebooked the other flights and with which were delayed as well

Could not get my connecting flight boarding pass until four hrs before departure! Ver annoying especially since the staff could not explain why!

The flight was flying with 30% capacity. The flight my seat from preferred seating to back of the seat. Even though i can understand that this was to balance the flight weight. The flight attendance decided to do the serving near my seat and in the middle , their noices woke me up from sleep , when i realized that the service has ended and when they were going back asked for a coffee, for which they answered they have completed teh service in my location. That really upset me as they woke me up and also rejected the coffee i asked. I ended up landing with a headache, thanks to the crew that screwed up my travel

Delayed initially because they couldn’t print the flight details. Poor instruction on delay. When I got on the plane the flight attendant argued with me about whether my carry on would fit (it did, although she didn’t acknowledge that). No greeting (other than arguing with me) getting on or off the plane.

Beverage service was not good. Also just one service in 5 hr 30 min flight. No ask fir water ir anything beside one time beverage service.

They are always late and seats was also not having working charger

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

Long delays, lack of information about the status of the flight. The flight was delayed 4 times.

Everything about the flight was lovely. My only suggestion would be to offer a few more options of tv series from Apple TV or HBO.

Delays to take off and to leave the plane after landing added a lot of time to this flight.

The Phildalphia to Allentown portion was a BUS, not a plane. All was as expected.

Excellent - explanations were clear staff was nice and flight was comfortable

Flight was delayed not sure why no explanation given and no apologies either. Otherwise the flight was fine

Flight was delayed more than 3 hours, and the metro had stopped running by the time we got to the terminal well past midnight, so I was stranded, alone, with no way to get home until the metro started up the next morning.

We get stuck in the plane when landed during 45min and no communication from the crew People were listening to their phone and music out loud and nobody told them anything I definitely want stop booking spirit flight it is a disaster

When I arrived at the airport at 4:00 in the morning, I was notified that I "hadn't paid" for my ticket (I had paid and had a boarding pass). Then I was told that while I had paid, the ticket was $600 more than it actually was, and that I needed to pay that so I could board. None of this was true, of course, but it took 20 minutes, two crew members behind the desk, and one on the phone to clear up.

The flight was delayed by two hours, then by three hours. Then, at 10:01, a notification that the flight was back on schedule for the original time. I just happened to be getting on a train to go to the airport at 10 just to be extra early for the delayed departure when I saw the update come through. I got to the train terminal at the airport at 11:07. A shuttle immediately arrived and offloaded, but didn't show anyone on before speeding off. It was 30 minutes before another arrived. I finally got to the terminal and through security and to the gate just in time for them to tell me the door had just been locked. Flight closed. I had to wait until the next day to fly out. No or for a hotel, a meal, nothing.

Good: It was cheap and they got us to our destination safely. Not so Good: Gates experience with many, many nauseatingly (almost) threatening announcements about bags size and how much they were going to charge us if our bag was too big, even to the point of having a gate agent roaming around through the passengers eyeballing bags size and making people go check their bags in the sizers.

For a change, friendly staff at check-in and in flight.

Delayed both in takeoff and landing, trash plane no amenities, I've said it before but I'll never fly Spirit again.

My flight was delayed by over an hour and the turbulance was horrible.

Everything is an additional fee. No one said anything when I checking in and got my boarding pass about my small carry on suitcase. Charged me $100 at the gate for that little bag that I still had to take with me. Delays for both flights for no reason and then when I asked everyone said something different. Never flying spirit again. If it was just one thing maybe. This was a show from the minute I got to the airport.

I had a great experience from booking to boarding to landing. This was the best experience from all the flights I’ve had with Spirit so far! The price and times were affordable and perfect. I will fly with them again soon!

Remind customers of the need to have passport or new ID for boarding.

Flight was canceled. Most upsetting was message from Kayak, stating that the flight was canceled and click with Kayak for details regarding rebook, refund details. THERE'S NO INFORMATION PROVIDED BY KAYAK EXCEPT THAT FLIGHT IS CANCELED. AND NOW THIS SURVEY TO FIND OUT HOW WAS THE FLIGHT !!!!!!!

The flight never took off and we spent 7 hours at the airport

Gate not determined until I got to the airport - hard to plan the trip to the airport.

Our flight was canceled. I will never use Kayak nor Frontier for travel again. The entire experience was a headache.

Frontier.. nickel and dime add-ons. Flight late, on time, late again, last minute gate change, arrival gate required a shuttle to the terminal. They sure keep you guessing.. if you like a little chaos and airport anxiety, this is the airline for you!

This is my second time flying with Frontier. My current experience was very favorable. The staff from the gate to the plane was friendly, warm and professional. The food options lacked in my opinion. This area needs some attention in my opinion.

First of all we hade waited 3 hours in the airplane waiting to leave. Second the return schedule was changed and it messed up my entire vaction. I won't buy never again another flight and recommend to nobody traveling with them.

There was no food and no entertainment, so I'm not sure why these are even in the survey, as my understanding is frontier does not ever offer food without a few, not even a snack, and there are no screens so unless the flight safety talk is our entertainment why ask how we liked it?. One of the flight attendants say in the back of the plane as people filed in to their seats, yelling orders about where to put baggage and telling people to hurry up. It was the least professional experience I've ever had on a flight.

Very well recently! Frontier is improving and less harrassing customer on luggages! Positive!

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

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