$89 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 5/5. 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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Cheap Flight Deals 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.

Recent round-trip flight deals from Philadelphia to St. Charles

KAYAK's recommended round-trip deals from the most popular airlines that fly from Philadelphia to St. Charles.
Discover the best prices for you by selecting your travel dates on KAYAK.
Frontier Logo
4:33 pm - 12:06 amPHL-STL
8h 33m1 stop
Frontier Logo
5:45 pm - 7:36 amSTL-PHL
12h 51m1 stop
$178Frontier
Find Deal
Mon, May 12 - Wed, May 14
Frontier Logo
10:59 pm - 12:06 amPHL-STL
26h 07m1 stop
Frontier Logo
5:45 pm - 7:36 amSTL-PHL
12h 51m1 stop
$181Frontier
Find Deal
Sun, May 11 - Sat, May 17
 Logo
12:59 pm - 9:09 amPHL-STL
21h 10m1 stop
 Logo
10:10 am - 10:43 pmSTL-PHL
11h 33m1 stop
Thu, May 29 - Thu, Jun 5
 Logo
4:00 pm - 6:41 pmPHL-STL
27h 41m2 stops
 Logo
10:10 am - 10:43 pmSTL-PHL
11h 33m1 stop
Thu, Jun 5 - Sat, Jun 7
American Airlines Logo
10:53 am - 12:27 pmPHL-STL
2h 34mnonstop
American Airlines Logo
6:00 am - 9:11 amSTL-PHL
2h 11mnonstop
$301American Airlines
Find Deal
Tue, May 20 - Wed, May 21
American Airlines Logo
7:14 pm - 8:58 pmPHL-STL
2h 44mnonstop
American Airlines Logo
5:00 am - 11:23 amSTL-PHL
5h 23m1 stop
$311American Airlines
Find Deal
Tue, May 20 - Wed, May 21
Southwest Logo
8:05 am - 9:30 amPHL-STL
2h 25mnonstop
Southwest Logo
8:25 am - 11:35 amSTL-PHL
2h 10mnonstop
$320Southwest
Find Deal
Wed, Jun 4 - Sat, Jun 7
Delta Logo
6:15 pm - 11:39 pmPHL-STL
6h 24m1 stop
Delta Logo
2:18 pm - 7:22 pmSTL-PHL
4h 04m1 stop
$321Delta
Find Deal
Tue, Aug 12 - Wed, Aug 13
Southwest Logo
8:05 am - 9:30 amPHL-STL
2h 25mnonstop
Southwest Logo
8:35 am - 6:45 pmSTL-PHL
9h 10m1 stop
$330Southwest
Find Deal
Wed, Jun 4 - Sat, Jun 7
Delta Logo
6:00 am - 9:33 amPHL-STL
4h 33m1 stop
Delta Logo
7:05 pm - 12:27 amSTL-PHL
4h 22m1 stop
$340Delta
Find Deal
Wed, Aug 6 - Thu, Aug 14
Useful Info

Good to know

Low seasonJanuary
High seasonJuly
Cheapest flight$89
Best time to beat the crowds but there is an average 12% increase in price.
Most popular time to fly and prices are also 42% 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 23m.

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

    11 direct flights run between Philadelphia and St. Charles on a daily basis. On average, there are about 77 departures each week.

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

    Consider leaving on a Monday and avoid Fridays if you are looking for the best rates. For your return to Philadelphia, you’ll find the best rates on Tuesdays and the most expensive ones on Thursdays.

  • 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 $89. Frontier offered a round-trip connection from $178 and Spirit Airlines from $263.

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 86 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 March, April and May. The cheapest month to fly is July.

Top 4 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 4294 reviews
8.2Boarding
8.0Comfort
7.1Food
7.6Entertainment
8.6Crew
Airline reviews

It is southwest seat was ok. Not the most comfortable seat

8.0 ExcellentJohn, Apr 2025PVD - FLL
Read more Southwest reviews

It is southwest seat was ok. Not the most comfortable seat

I’ve always loved Southwest. No issues at all. I was flying standby and the gate agent was extremely friendly and helpful. Boarding was smooth and I was able to get a window seat in the emergency exit row. Crew was fantastic! They were very professional and accommodating. We had to divert from our destination due to weather but the flight crew kept everyone at ease and informed us of all pertinent information. Excellent flight

The price of the tickets isn't matching the flight experience. No matter how long the flight is, you're only getting pretzels. The flight attendants looked unkept and over it.

Plz don't take away free bags and free seating

The seats were a bit cramped and worn, but otherwise okay.

I would have liked to arrive on time - not 5 hours late!

After a 3 hour layover in Denver my flight was delayed over 5 hours! No explanation; no assistance; no offer to provide compensation; no one at Southwest was willing to offer any assistance. 8 hours in the Denver airport - ridiculous!

It was a perfect flight in all aspects! Both legs!

Only one drink pass through the cabin for a 4 hour flight. Quite rough and bumpy landing.

Boarding process, crew were good. But the seats were so uncomfortable that was all I could focus on. I literally had to sit forward so that all 3 of us could fit in row. I will try to avoid Southwest in the future for any flights over 60 minutes.

Delta is my preferred airline. I've traveled with them for years. On time in most cases, good communication, easy to use app. Most planes are pretty nice. I was on a CRJ 700/900 however, which was pretty badly aged inside and needed a refresh. No infotainment, unreliable wifi, best to download before boarding or bring a book. Food choices are really just snacks on this flight, nice variety but about what you'd expect. Great staff and prompt in departure and early arrival too. Overall quite satisfied.

Crew was friendly Love the entertainment in the seat head rest.

Delta flight was on time, seats were comfortable, and crew was nice.

This had nothing to do with Delta… The flights were on time and flawless. The service was excellent. We purchased seats in (aisle/middle) comfort plus since this was a cross country flight. Unfortunately, the woman seated at the window was 300+ pounds and, as might be expected, covered up about a third of the middle seat also. there was absolutely nothing that Delta could have done about that… I just don’t know what the answer should be. If you purchase a seat, you should should be able to use the entire seat and not just the portion that someone else is not sitting/oozing in. Disappointing…there should be something that could be done….I'm just not sure what solution could be.

Delayed take-off. Very small plane so very scary with lots of bumps during the flight. Would never fly Delta on short flights in small 80 seaters plane again! Felt relieved when landed.

The worst part was I was NOT allowed in the lounge even though I was holding a first class ticket and have a premium American Express card. I have flown Business or First Class with many airlines. Delta is the ONLY one who does not extend this courtesy to anyone except people who hold the very expensive American Express card. As a result, I won’t fly Delta if I have any other choice.

A little bumpy ride . No food was being provided due the the turbulence. That was ok it was a short flight to my standards.

Simply outstanding. Their new lounge for Delta One customers is a cut above the rest.

The Dekta Rep that checked us in was great. She's very personable, pleasant, and can tell she enjoys her job.

The plane was old with small storage areas that had problems closing/latching and not enough storage for everyone, and worn, damaged seats. Service was great but feel a little unsafe on such well used planes.

Everything about the flight was lovely…We left early, arrived early, cabin crew were efficient and helpful. Flight was easy and most pleasant.

Everyone was nice. It was on time and the food was. Airplane food, but not horrible

One bottle of water and a package of cookies for comfort plus. We had to literally beg a flight attendant for an extra bottle of water later in the flight due to feeling dehydrated.

late again! but its my only option to not take 9 hours to get to Memphis

Almost everything was outstanding. First, we boarded on time and the flight crew did a great job getting everyone seated. Then the pilots took their time and care to make sure the plane was full de-iced three times as there was a bad ice storm a few hours earlier. The plane ride was smooth and comfortable and even the economy seats had decent room and comfort. Flight Attendant Lisa went above and beyond to make sure I was comfortable - she is outstanding. The only thing wrong with the flight, and it is something which needs to be addressed, is that the gate to gate time was over 6.5 hours and not one meal was served. The only thing offered to eat were two small cookies for a transcontinental flight - unacceptable. Charge me more but give me a meal for a long flight. Thankfully Lisa found something for me.

Very poor. Our special services attendant gave us incorrect information. I also was mishandled at landing. There was no wheelchair waiting. I fell deboarding the plane. Appalling!

I had a very unpleasant encounter with one man from customer service: he was extremely rude and miserable. And his condition was reflected on his decision to send me to the worst airport hotel and get an awful flight connection. My hotel shuttle had never arrived and I had to book another hotel. People served by other representatives got a much better treatment and deal.

The flight left a bit late, but arrived close to time expected…With the flight being close to full the crew did well serving drinks to all in a very timely fashion. The flight was a pleasure…

They didn't have any gluten-free snacks, oddly, which I require...or any flavored soda water or decaf tea options, which seems to be standard.

My flight back my reservations were list because they said I didn't pay my pet fee when I had a receipt

The reps working at the airport counter were dumber than a second coat of paint.

My costume jewelry was stolen out of my bag. Got to airport and my bag weighed 45 pounds- 5 pounds over cost me $100 Long lines in tier one. No entertainment No WiFi no free drinks or snacks

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

The seats were hard molded plastic covered in plastic vinyl. And the scam to charge people extra to sit together. Don’t they know we can just ask someone to trade seats. And watching the staff separate young children from parents… super classy. We had to guilt them into offering up our seats. This companies policies suck. Don’t give them your money.

The seats were awful, hard plastic covered in sheet vinyl. The airline tries to scam you into paying extra to get seat together when the flight wasn’t full. They were going to separate a family with young children but my wife who had a row to herself gave up her seat so the young mom could be with her young boys. I’m never giving this airline my money again.

It was a short flight so no food or entertainment….

Seats are uncomfortable but price is good. Guess I can put up with misery for four hours.

I’ve never traveled on Frontier before. If you want basic, no frills, friendly service at great prices then give them a fly!

Cancelled and declined to find alternatives Earlier flight is 2 days later Sent the cancellation notification very late, wish I knew earlier would have stayed to watch the Miami open final game Very disappointing service

The worst flight of my life. Never will I fly frontier again

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

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