$70 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 5/26. 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
$257
Typical prices: $429-$232
Southwest
Tue 8/18Tue 8/25
PHL - STL • Non-stop
Cheapest one-way
$70
Typical prices: $150-$265
Frontier
Tue 5/26
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

Tue, Aug 18 - Tue, Aug 25
Southwest Logo
6:25 am - 7:40 am
PHL
-
STL
2h 15mnonstop
Southwest Logo
10:55 am - 2:05 pm
STL
-
PHL
2h 10mnonstop
$257Southwest
Thu, May 14 - Thu, May 28
Multiple Airlines Logo
6:10 pm - 12:21 am
PHL
-
STL
7h 11m
1 stop
Multiple Airlines Logo
6:33 pm - 11:53 pm
STL
-
PHL
52h 20m
2 stops
$266Multiple Airlines
Tue, May 26 - Tue, Jun 2
Southwest Logo
6:35 pm - 8:00 pm
PHL
-
STL
2h 25mnonstop
Southwest Logo
2:30 pm - 10:00 pm
STL
-
PHL
6h 30m
1 stop
$267Southwest
Mon, May 18 - Thu, May 21
Frontier Logo
12:59 pm - 12:21 am
PHL
-
STL
12h 22m
1 stop
Frontier Logo
4:19 pm - 12:40 am
STL
-
PHL
7h 21m
1 stop
$269Frontier
Wed, Jun 24 - Sun, Jun 28
Frontier Logo
1:28 pm - 12:09 am
PHL
-
STL
11h 41m
1 stop
Frontier Logo
8:08 pm - 5:38 am
STL
-
PHL
8h 30m
1 stop
$270Frontier
Wed, Aug 12 - Wed, Aug 19
Southwest Logo
1:45 pm - 8:00 pm
PHL
-
STL
7h 15m
2 stops
Southwest Logo
10:55 am - 2:05 pm
STL
-
PHL
2h 10mnonstop
$272Southwest
Wed, May 20 - Sat, May 23
Multiple Airlines Logo
12:17 pm - 2:31 pm
PHL
-
STL
27h 14m
1 stop
Multiple Airlines Logo
5:27 pm - 9:25 am
STL
-
PHL
14h 58m
2 stops
$273Multiple Airlines
Wed, May 27 - Sat, May 30
Southwest Logo
6:35 pm - 8:00 pm
PHL
-
STL
2h 25mnonstop
Southwest Logo
6:55 pm - 10:05 pm
STL
-
PHL
2h 10mnonstop
$274Southwest
Sat, May 23 - Wed, May 27
Multiple Airlines Logo
2:57 pm - 11:57 pm
PHL
-
STL
10h 00m
1 stop
Multiple Airlines Logo
5:27 pm - 9:25 am
STL
-
PHL
14h 58m
2 stops
$276Multiple Airlines
Wed, May 20 - Wed, May 20
Delta Logo
8:05 am - 12:20 pm
PHL
-
STL
5h 15m
1 stop
Delta Logo
6:04 pm - 11:07 pm
STL
-
PHL
4h 03m
1 stop
$277Delta
Useful Info

Good to know

Low seasonFebruary
Cheapest flight$70
Best time to beat the crowds but there is an average 5% increase in price.
Most popular time to fly with an average 14% 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 20m.

  • 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 78 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 Thursdays 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 $61. 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
8.6Crew
7.5Entertainment
7.0Food
8.1Boarding
8.0Comfort
Airline reviews

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

10.0 Excellentlarry, Apr 2026
LGB - PHX
Read more Southwest reviews

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

no service at all due to turbulence. they should've at least given us snacks, there were only 10 people on the entire flight.

First time I've had to use the disabled accommodations. And I could not have had a better experience with Southwest, i was having trouble getting from one terminal to another due to my heart failure. And the next thing I know a Southwest agent had made sure. I had a wheelchair at all my flights. Can't thank them enough.

Delayed flight, lack of information, boarding process is a mess as is the carryon luggage causing issues when leaving the plane….just a poor experience.

Comfortable. Easy. No problems. Just wish they had gf options for snacks.

The crew was very kind and made going to Hawaii relaxing and fun to look forward to! Thank you Southwest for a pleasant flight!

This leg was much better, but we did have to have a 3 hour lay o er after coming from a very exhausting hiccup with our flight from BNA to Den

We waited in the airplane for over 45 min for a southwest employee to make the flight. This cause over half the plane to miss their connecting flight in Denver. When we confronted the desk upon arrival, they told us the only flight they had was the next day leaving at 8:50 pm!!! Or they offered to get us to Burbank or LA, but after that we were on our own to get back to Santa Barbara. I paid for a flight from sba to bna bna to sba. My re entry into mom mode has been 💯 rough because of southwest mistake with my flight. And now I’m leaving to Reno tomorrow for a vballl tournament and just discovered that my leg in Vegas has me and my 3 kids on a stand by flight even though I had booked these ticket last year November!! Do better southwest!

Southwest is kind of a slum airline. It’s gotten more expensive over the years for less and less service. I am a Southwest Chase Visa card holder and was forced to choose a seat in the 26th row in the middle seat. However my wife who is a rewards member but doesn’t hold a card or anything else, gets randomly assigned a normally paid seat in row 6! How does that work?

For the first time in a long time, the Wi-Fi actually worked the entire flight! The flight crew was amazing as usual.

The agent at check in and at the gate were less than thrilled to be at work. I'm not a fan of Kayak's placement on the plane. I got put in the middle seat and none of my preferences were used.

In ATL they have two sets of departure screens. Follow what is on your airline's departure board - the ATL Airport Authority departure board had completely incorrect details about the gate assignment for my flight, which would have made me miss boarding.

Flight was delayed it was hot while sitting on the plane, one engine was working on the plane until they had to do some jimmy rigging down the runway in order for the other engine to charge up. It was ridiculous

The flight was very good and the staff was very friendly and helpful!

The only thing I would say is we tried to get on a standby earlier flight, but with our fair we couldn’t. That seems senseless to leave with open seats..

Very easy to use and convenient, you can perform any action within the same portal

In a world of delays, Delta was on time both ways! Boarding was fast and efficient. Staff was friendly. AND wifi worked.

WiFi didn’t work. Flight delayed 3 hours Crew members were illiterate Seat lean back did not work.

Flight was delayed, we could have been notified earlier and in a consistent manner. App was not refreshing for another passenger to get the latest flight status. We could have stayed and waited at the hotel instead of waiting at the airport had we known the flight was going to delayed for more than 5 hours. The toilet is too tight, and needs to be cleaned more frequently (every hour). The entertainment screen froze, the touch screen not responding to touch. We were upgraded to comfort, it is more comfortable than regular economy seats.

This wasn't my experience with Delta. It was just the Pegasus flight. Seats were very hard. Staff was kinda rough. Not very nice. Charged me for snacks. For a 4 hour flight I would've expected more.

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

Half of the TSA checkpoints at PHL are closed. Also, there is no standby for first class passengers. You can only standby for coach. Very dated policy and inconsistent with peers.

It would have been nice if American tried to care.

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

The agent cancel my flight without my consent. So the situation generate me a lot of troubles, specially because we were traveling with a baby

Wonderful! Very polite crew that was dedicated to excellent customer service

Everyone was nice but it's budget. There's nothing free and no entertainment

The flight was delayed for over an hour. No one at the gate said anything about the flight being delayed. I had to rely on my phone for updates. Absolutely no communication at the gate.

The AC broke and we were onboard for 2 hrs waiting for them to fix it. It was so hot and we could not get any water or anything to drink. They finally let us off the plane after the second attempt and we boarded a new plane. We didn't land till 12:15am!

The boarding process was simple but the seats were very uncomfortable. The staff lady was also very hard to understand when she spoke over the intercom about procedures and updates. Other staff members seemed like they were just tired and didnt want to be on the plane. Im used to happy attendants and being able to understand what is said over the speakers.

There was no flight. Call the airline and confirmed. I have no idea why you think that I flew on the days that you say I did.

They canceled my flight and never told me. There was no follow up email. I had to buy another ticket the day of.

Easy to get our TSA pre check #added. Flight crew was great and entertaining and we landed early!

Flight was delayed 6plus hours Did not take flight Customer service was terrible Will never fly again and will spread how terrible you are You stink

The bag check, flight check-in, and onboard experience convinced my wife and me that we will actively go out of our way to avoid flying Frontier Airlines in the future. At bag check, we were informed that check-in could only be completed via the Frontier mobile app. Unfortunately, the app was extremely frustrating—sending us through repetitive, confusing loops that repeatedly forced us to decline add-on services with nearly every click. While most airline apps upsell, this one felt intentionally exhausting. As the process dragged on, we became genuinely concerned that my phone battery would die before check-in could be completed. We approached the bag check staff—who were standing together talking—and explained both our frustration and our predicament. They laughed. Later, my wife described the interaction as “gaslighting,” which felt accurate. We were then informed it would cost $25 per person simply to have our boarding passes printed. From that point forward, the tone of the experience was consistently hostile. The bag check employees were condescending and combative, behaving more like bullies than customer service staff. Unfortunately, that same attitude continued onboard. One flight attendant argued with me when I attempted to stow my backpack in the overhead bin. I explained that we had each paid $75 to check our bags specifically so we would not need to use carry-on space and could have adequate legroom. She demanded to see my ticket, pointed out that it said “no carry-on”—which I acknowledged—and I reiterated that this was precisely why we paid to check our bags. Her response was, “I don’t make the rules.” She then walked away, but not before asking if I “truly wanted to fly back to Chicago today?”—an unnecessary and unmistakable threat. It is also worth noting that despite booking our tickets together in the same transaction, we were not seated together. Upon our return to Chicago—where we could once again sit together—we compared onboard experiences. We both remarked on how unhappy the flight attendants appeared and how each of us was separately asked whether we would like to purchase a beverage. We declined. At no point was water mentioned as an option, leaving us with the clear impression that even water came at a cost—or that complimentary water, if available at all, was deliberately left unmentioned. Overall, the experience was shocking and deeply disappointing, but it was also a profound learning experience—one we will not forget and will not repeat. -Steve

Plane was hot and miserable and the crew was rude!

12 hour delay required getting on and off plane 3 times - would have at least liked to have been offered a snack or drink

They didn’t offer a water, even after I asked

They switched our terminal 3 times and we were delayed for four plus hours!!!

It was an early flight and most people napped/slept and the crew let us which was nice.

The crew acted like they had never done this and kept barking passive aggressive orders at people. + the security line + the delay + sitting on the tarmac for 2 hours + none of the apps or signage updating with correct times

More inflight connection. And leg space is horrible. And the paying for baggage I'd ridiculous!!!

My flight was originally from SAT to MCO connecting from MCO to ORD. We got diverted to ATL and than Frontier staff there was sooo un helpful first they said they couldn’t give us any accommodation since our flight first got delayed that cancelled and now it’s 221am and I am still in ATL since they said they need to create a new flight my final destination is ORD and I have been delayed twice and cancelled. With no real help the frontier app didn’t work no email updates over all such a horrible experience

There's no seats that lean back with little leg space i wad uncomfortable the entire flight. Your charges for extra baggage is despicable and costly!!

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

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