$57 Find Cheap Flights from St. Louis to Pennsylvania - 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 St. Louis to Pennsylvania departing on 10/26. 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.
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Cheap Flights from St. Louis to Pennsylvania

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Philadelphia
Philadelphia1 stop$126
Pittsburgh
Pittsburghnonstop$197
Harrisburg
Harrisburg1 stop$301
Allentown
Allentown1 stop$297
Scranton
Scranton1 stop$297
State College
State College1 stop$319
Williamsport
Williamsport2 stops$961
Washington, D.C.
Baltimore1 stop$139
New York
Newark1 stop$214
Philadelphia
Philadelphia1 stop$126
Pittsburgh
Pittsburghnonstop$197
Harrisburg
Harrisburg1 stop$301
Allentown
Allentown1 stop$297
Scranton
Scranton1 stop$297
State College
State College1 stop$319
Williamsport
Williamsport2 stops$961
Washington, D.C.
Baltimore1 stop$139
New York
Newark1 stop$214

Book Cheap St. Louis to Pennsylvania Plane Tickets

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

Fri, Oct 2 - Mon, Oct 5
Frontier Logo
2:29 pm - 11:18 pm
STL
-
PHL
7h 49m
1 stop
Frontier Logo
8:41 am - 1:10 pm
PHL
-
STL
5h 29m
1 stop
$146Frontier
Thu, Aug 20 - Mon, Aug 24
Frontier Logo
6:17 pm - 7:15 am
STL
-
PHL
11h 58m
1 stop
Frontier Logo
8:30 am - 5:22 pm
PHL
-
STL
9h 52m
1 stop
$147Frontier
Wed, Aug 26 - Wed, Sep 2
Southwest Logo
10:25 am - 1:05 pm
STL
-
PIT
1h 40mnonstop
Southwest Logo
7:20 pm - 8:00 pm
PIT
-
STL
1h 40mnonstop
$197Southwest
Thu, Aug 27 - Thu, Sep 3
Southwest Logo
7:35 pm - 10:15 pm
STL
-
PIT
1h 40mnonstop
Southwest Logo
7:00 am - 7:45 am
PIT
-
STL
1h 45mnonstop
$197Southwest
Thu, Aug 27 - Thu, Sep 3
United Airlines Logo
8:00 am - 1:15 pm
STL
-
PIT
4h 15m
1 stop
United Airlines Logo
6:09 pm - 10:59 pm
PIT
-
STL
5h 50m
1 stop
$212United Airlines
Sat, Sep 12 - Sat, Sep 19
American Airlines Logo
7:27 am - 12:32 pm
STL
-
PIT
4h 05m
1 stop
American Airlines Logo
8:47 pm - 12:27 am
PIT
-
STL
4h 40m
1 stop
$217American Airlines
Thu, Sep 3 - Mon, Sep 7
American Airlines Logo
6:00 am - 11:54 am
STL
-
PIT
4h 54m
1 stop
American Airlines Logo
8:59 pm - 12:14 am
PIT
-
STL
4h 15m
1 stop
$217American Airlines
Tue, Aug 18 - Sat, Aug 22
Delta Logo
11:00 am - 5:14 pm
STL
-
PIT
5h 14m
1 stop
Delta Logo
5:50 am - 11:56 am
PIT
-
STL
7h 06m
1 stop
$217Delta
Thu, Sep 3 - Mon, Sep 7
Delta Logo
6:30 am - 11:19 am
STL
-
PIT
3h 49m
1 stop
Delta Logo
5:50 am - 9:20 am
PIT
-
STL
4h 30m
1 stop
$217Delta
Thu, Aug 20 - Fri, Aug 21
United Airlines Logo
8:00 am - 1:15 pm
STL
-
PIT
4h 15m
1 stop
United Airlines Logo
6:09 pm - 10:01 pm
PIT
-
STL
4h 52m
1 stop
$232United Airlines
Booking Insights

KAYAK's insights & trends for St. Louis to Pennsylvania flights

Get data-powered insights and trends into flights from St. Louis to Pennsylvania to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from St. Louis to Pennsylvania?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from St. Louis to Pennsylvania departing in November.

Flight prices are below average for this route right now.

Flights to Pennsylvania from St. Louis usually cost between $277 and $471 in November.
The lowest price found in the past 5 days was $126 on Frontier (Nov 9-Nov 11).

What is the cheapest St. Louis to Pennsylvania flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest ticket to Pennsylvania from St. Louis found in the last 5 days was to Pittsburgh, at $219 round-trip. The most popular route is from St. Louis (STL) to Philadelphia (PHL), and the cheapest round-trip airline ticket found on this route in the last 5 days was $269.

What is the cheapest time of day to fly to Pennsylvania?

The average price for all round-trip flights from St. Louis to Pennsylvania depending on the time of departure, clicked by users on KAYAK in the last 2 weeks.

The cheapest time of day to fly to Pennsylvania is generally at night, when round-trip flights cost $471 on average. Morning departures are around 7% cheaper than evening flights, on average. The most expensive time of day to fly to Pennsylvania is generally in the afternoon, which is peak travel time and where the average cost of a ticket is $906.

Can I save money by flying with a layover from St. Louis to Pennsylvania?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of $418, prices are generally cheapest when you fly direct.

What is the cheapest month to fly from St. Louis to Pennsylvania?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to Pennsylvania, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from St. Louis to Pennsylvania is September, when tickets cost $321 (return) on average. On the other hand, the most expensive months are July and March, when the average cost of round-trip tickets is $449 and $437 respectively.

What’s the cheapest day of the week to fly from St. Louis to Pennsylvania?

The average price of all round-trip flights from St. Louis to Pennsylvania clicked on KAYAK for each day over the last 12 months.

If your flying dates are flexible, you should consider flying to Pennsylvania on a Friday, as we generally find the cheapest rates on that day for this route. On the other hand, Saturday is the most expensive day to fly from St. Louis to Pennsylvania. For your return ticket, we recommend flying on a Wednesday and avoiding Sundays for the best deals.

How far in advance should I book a flight from St. Louis to Pennsylvania?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from St. Louis to Pennsylvania, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from St. Louis to Pennsylvania, you should book around 4 weeks before departure, which saves you about 27% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 15 weeks before departure.

Good to know

Low season

February

Cheapest flight

$57
Best time to beat the crowds with an average 9% drop in price.
Flight from St. Louis to Philadelphia

FAQs - booking Pennsylvania flights

  • How does KAYAK find such low prices on flights from St. Louis to Pennsylvania?

    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 St. Louis to Pennsylvania.

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

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

    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 from St. Louis to Pennsylvania with an airline and back with another airline.

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

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

Top tips for finding cheap flights to Pennsylvania

  • Looking for a cheap flight? 25% of our users found tickets from St. Louis to the following destinations at these prices or less: Newark $256 one-way - $391 round-trip; New York $221 one-way - $337 round-trip; Philadelphia $278 one-way - $359 round-trip

Reviews of the top 5 airlines serving from St. Louis to Pennsylvania

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Pennsylvania. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from St. Louis to Pennsylvania? 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 4227 reviews
8.0Comfort
7.5Entertainment
8.1Boarding
8.6Crew
7.0Food
Airline reviews

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

6.0 GoodAnonymous, Mar 2026
STL - HOU
Read more Southwest reviews

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

Only downside was the legroom and seat width, which is always a problem unless I spend more for a premium seat.

Very good. Sad to learn Southwest is going start to charge for bags

Exceptional crew! Friendly and professional. Pleasant attitude and treated everyone with respect.

The flight was promptly on schedule and Southwest delivered everything they promised. No excuses for any shortfalls just 100% ownership of their responsibilities and business. The boarding and seating policy is a complete shambles. What started out as a great idea when Southwest first hit the market has been turned into a disaster due to the lack of integrity in many of the people who fly Southwest and take advantage of Southwest generosity at the expense of their fellow passengers.

Crew was excellent - Plane was fine. Media was good, could use more kid shows; Not a fan of the brownie brittle -- snack could be slightly better.

Left on time and arrived early. Brand new plane and no parts missing. Comfortable seats. The actual Captain spoke prior to the flight and reassured everyone about safety. Crew was so nice and fun. Perfect flight!

Everything went smoothly and the plane wasn’t full. It was delayed though. The delay was increased due to a crew change which was frustrating.

Love Southwest! Always a good trip with a happy crew who goes out of their way to be kind and fun.

friendly staff for the most part. they thought we were going to have bad turbulence so no drink service. there wasn't any turbulence. Iwish you had a choice of snacks

From checking to boarding, it was a seamless experience. The service agents were so helpful. The flight crew was so pleasant.

Only beverages were offered to first class and I thought the flight attendant could have also served the Delta Comfort as well instead of sitting down and staring at her phone and walking past all of us to the back of the plane to charge her phone more. There was a complete lack of turbulence and was safe enough for flights attendant to walk around in the front of the plane, collect trash and serve a few people water and turn off the seat belt light. Also didn’t enforce people putting their seats into the upright position and allowed two passengers to remain reclined during landing. They seemed out to lunch completely. Usually my experience on Delta is much better.

My tray was broken so i had no place to work or eat except my lap. Flight attendant said I would get an email with some credit or miles, it was a complete waste of time as I could only function at about 20% of normal. I have not received anything yet.

Delayed. Hot. Passenger next to me was so large I couldn’t move.

2+hrs delay without any reason provided and a cramped flight

Great flight with Delta! Boarding was quick and easy, the amenities were solid, and the plane was in great shape. The flight attendants had a fun, lively energy while staying professional. All in all, a smooth trip — even managed to catch up on some rest. Thanks, Delta!

My flight was canceled after being rescheduled for four days canceling my trip. Kayak and everyone affiliated with it I.e the airlines, and just fly have been excruciating to deal with. My trip to visit family had to be canceled as there was no way to make it. I am furious at all of you.

They delayed our flight because of bad weather in NY which was completely understandable. Then they cancelled our flight and a later flight that evening. The earliest we could fly was the next morning. We ended up buying last minute tickets on another airline and made it home slightly delayed but safely that evening. Delta kept saying it was weather related but if that was the case how did we make it back on another airline? The weather in NY was cloudy but not bad.

The plane smelled like a sewer. Multiple passengers complained. It’s a safety and quality issue to clean these planes.

We were delayed 2 hours leaving STL. I had 20 mins from when we landed in SLC terminal A to make it to SLC terminal B. I had to actually run! thankfully I made my flight but 3/4 legs were delayed to some capacity.

Our flight was great with an unexpected upgrade. However, four days into our travel we are still without a piece of luggage. The bag tracker has not been accurate, the airline is not communicating with me or the luggage delivery service and no one is willing to take responsibility or guarantee any kind of support or reimbursement. Unfortunately, we do not have the option to easily shop to replace items as we are currently on a cruise. I have been very disappointed by United Airlines response.

United didn’t even try to hold the flight for me. They knew I had a tight connection and when I arrived at the gate less than 10 mins after final boarding the flight had already gone. The gate agent wasn’t even notified that I was on my way. She was told I wasn’t at the airport

Everything went well except the turbulence what no one have a control of but pilot and crew handled very good!

HORRIBLE, my initial flight was cancelled, they made me pay $200 extra dollars and that got cancelled as well! After 6 cancellations I decided to get a refund because I needed to get home to my babies. Out of $1000+ dollars they offered me only $40 in refund! Totally unacceptable! The flight that they cancelled I was able to fly it on another airline. I had to spend $400 on one way tickets just to get home! I’m still getting the runaround.

Flight was delayed only slightly before takeoff due to traffic control. However, the flight arrived early to ORD. Good flight. United has been very reliable for me.

Overall a very poor experience - booked premium economy tickets but due to last minute flight delays , all my itinery went for a toss and had to fly economy class with no access to lounge or any compensation by united airlines to make up for the flight delays . i had expected better experience than that from united.

I still prefer Delta, but Delta doesn’t fly to State College PA.

This flight was delayed multiple times and eventually canceled around 2-3ish. Original take off time was around 10:30am. By 3, there were no other options out of Houston, so stuck in Houston for from 3pm - 11am the next day.

Onboarding - it would be great to see on the screen what group they were boarding. It was very confusing on who was boarding (even though they called it out) they were not clear and the space to board was strange.

Older plane. Food was really bad, almost not worth the effort. Huge difference with European based airlines.

My luggage was not sent with us. Not sure if this is Envoy Air responsibility but that was a very BAD experience

American delayed the flight for a crew rest period. The delay occurred late in the evening - the earliest i can find is 10:20 pm. With a 6 am flight anyone on the flight would have already have been asleep (unless you are insane, a vampire or on drugs) and at least for me i was already on the way to the airport at 445 am the next morning when i discovered they delayed the flight until 9 am. Given the incoming flight was in the air at 6 pm the evening before this should have been figured out a lot more timely that was there only crew to use. Just frustrating given there is no consideration for customer experience anymore in flying.

Good crew and flight was on time. It’s a small plane with limited overhead luggage space. They said the overhead space was full and I had to check my bag. There was still space when I got on. Waiting for my checked luggage added 30 minutes to my trip. Not the end of the world but also not great.

Trip delayed for 2 hours because of rain. We boarded and have to get down the flight and reboard again.

No enough space plus only allowing one laggage instead of two like other airlines.

Qatar airways ,boarding arrangements at Hamid international airport could been better

Two flight changes before the scheduled flight. On the day of the flight, the flight was delayed, which caused the connecting flight to be missed. Then, I was directed to another airport (CUN) and traveled to Tulum. American gave a $12 voucher for lunch. The least expensive item on the menu at a Mexican restaurant was $9.99. Driving to Tulum was a bad auto crash, and traffic was delayed two-plus hours. The bottom line is that we should have been at the hotel at noon, but it ended up at 11:30 PM.

Miami lounges were overcrowded and we were unable to get in. We only had a short time. But the banks are too tight in all American hubs

Overall boarding and debarking is a joke. I dont even bring luggage anymore on trips because you can never allow them to be place then in the overhead bin or you have to pay or you check them which is even worse having to wait for your luggage on the tarmac.

First time flying internationally with AA and probably my last. Not military friendly at all. Didn't allow free checked bag for military family members (dependents) on orders like other airlines. We were charged $100 for baggage weight overage (5 lbs!)even though we had military orders allowing us extra.. Didn’t allow military members to board early. Inefficient and long wait time to board. Seats are smaller and more uncomfortable than other airlines.. no drink service for over 7 hrs of flight! After initial meal was served, the crew never offered a snack or drinks until the breakfast's was served 1 1/2 hrs before landing. Overall expensive and poor experience for the entire flight.

Not clean and was told I would get a great seat and it was not great at all

No knowledgeable staff at the counter or in a flight crew. No one knew why once flight landed at Philadelphia Airport then it took them 4 hours from runway to gate . Damn they took 4 hours to reach the gate . They messed up whole night for myself and for my kids.

Horrible communication about delay of flight and what options were available

Online check-in was not user-friendly. Too many fees, not cost effective.

FRONTIER SUCKS! The agent downstairs tricked me into booking, just to get to the gate. At the gate, they told me they couldn't help. I then called Customer Service. They and the gate attendants kept blaming each other. Neither side was willing to help the customer.

I had a terrible experience with Frontier. I arrived before the 60 minute cut off and was told that Frontier has a two hour window for bags. I was then told the next available flight wasn’t until the end of the day (I had booked a 6am flight). I took a look around and saw other people being told that they could not board their flights or that they had to pay additional fees. I opted to rebook on American Airlines. There’s absolutely no straightforward way to contact Frontier, so this ticket was a complete waste of money. Oh - and the kicker is that the lady lied about the two hour cut off.

My experience with frontier staff at the Denver airport was absolutely horrible. The manager on duty was even worst if was the worst experience I have ever had, I have never been treated so poorly as a customer in my life! The staff was extremely rude, eye rolls and attitude and then refusal to help me at all. I wish I could never fly frontier again that’s how horrible it was!

Good for the price. My only complaint is that the pilot should keep the air flowing while passengers are waiting to getting out of airplane.

I arrived 1 hour prior to boarding, and they said I was too late for a domestic flight. First time I heard that :-(

I have come to accept Frontier as an absolute no-frills airline, paying for everything I want. A 4.5-hour flight should provide me with a complimentary beverage—rather, $4.9x for a soda. Or a bottle of water ought to be extended at no cost. 4 beers are on the menu, but only 1 type of beer is available (at $9.95). Also, so many restrictions to using a voucher from Barclay‘s Credit Card. Finally, try to reach a live agent for Frontier- impossible!

Everything you need to know for your flight from St. Louis to Pennsylvania

Information on your arrival and departure airports