$59 Find Cheap Flights from St. Louis to Pennsylvania

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 3/11. 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

KAYAK searches hundreds of travel sites at once for deals on flights to Pennsylvania

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Pennsylvania.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Pennsylvania.
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 23% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Flight Deals
Booking Insights
Flight Deals

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$134
Pittsburgh
Pittsburgh1 stop$177
Harrisburg
Harrisburg1 stop$192
Allentown
Allentown1 stop$349
Scranton
Scranton1 stop$506
State College
State College1 stop$309
Washington, D.C.
Baltimore1 stop$131
New York
Newark1 stop$128
Philadelphia
Philadelphia1 stop$134
Pittsburgh
Pittsburgh1 stop$177
Harrisburg
Harrisburg1 stop$192
Allentown
Allentown1 stop$349
Scranton
Scranton1 stop$506
State College
State College1 stop$309
Washington, D.C.
Baltimore1 stop$131
New York
Newark1 stop$128

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

Tue, Feb 3 - Sun, Feb 8
Multiple Airlines Logo
5:42 pm - 10:49 am
STL
-
EWR
16h 07m
1 stop
Multiple Airlines Logo
5:25 am - 6:51 am
EWR
-
STL
26h 26m
1 stop
$128Multiple Airlines
Mon, Feb 23 - Mon, Mar 2
Multiple Airlines Logo
8:22 pm - 8:05 am
STL
-
EWR
10h 43m
1 stop
Multiple Airlines Logo
10:30 pm - 10:27 pm
EWR
-
STL
24h 57m
1 stop
$132Multiple Airlines
Fri, Feb 6 - Sat, Feb 7
Frontier Logo
8:22 pm - 11:18 am
STL
-
PHL
13h 56m
1 stop
Frontier Logo
3:54 pm - 11:33 pm
PHL
-
STL
8h 39m
1 stop
$157Frontier
Thu, Apr 30 - Sat, May 2
Frontier Logo
8:12 pm - 5:34 am
STL
-
PHL
8h 22m
1 stop
Frontier Logo
12:46 pm - 11:19 pm
PHL
-
STL
11h 33m
1 stop
$160Frontier
Sat, Feb 21 - Mon, Feb 23
American Airlines Logo
6:53 pm - 12:27 am
STL
-
PIT
4h 34m
1 stop
American Airlines Logo
3:32 pm - 8:16 pm
PIT
-
STL
5h 44m
1 stop
$189American Airlines
Mon, Feb 16 - Wed, Feb 18
American Airlines Logo
6:57 pm - 12:27 am
STL
-
PIT
4h 30m
1 stop
American Airlines Logo
12:20 pm - 3:35 pm
PIT
-
STL
4h 15m
1 stop
$213American Airlines
Sat, Feb 21 - Mon, Feb 23
Southwest Logo
3:55 pm - 6:30 pm
STL
-
PIT
1h 35mnonstop
Southwest Logo
4:10 pm - 10:40 pm
PIT
-
STL
7h 30m
1 stop
$251Southwest
Wed, Feb 18 - Sat, Feb 21
Delta Logo
10:14 am - 4:28 pm
STL
-
IAD
5h 14m
1 stop
Delta Logo
10:57 am - 3:56 pm
IAD
-
STL
5h 59m
1 stop
$253Delta
Tue, Feb 24 - Tue, Mar 3
Delta Logo
6:00 am - 11:10 am
STL
-
MDT
4h 10m
1 stop
Delta Logo
5:55 pm - 11:36 pm
MDT
-
STL
6h 41m
1 stop
$260Delta
Thu, Mar 12 - Mon, Mar 16
Southwest Logo
4:25 pm - 11:40 pm
STL
-
PIT
6h 15m
2 stops
Southwest Logo
8:45 pm - 12:05 am
PIT
-
STL
4h 20m
1 stop
$266Southwest
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 February.

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 72 hours was to Pittsburgh, at $249 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 72 hours was $349.

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 $369, 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 August, when tickets cost $277 (return) on average. On the other hand, the most expensive months are November and February, when the average cost of round-trip tickets is $493 and $443 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 Thursday, as we generally find the cheapest rates on that day for this route. On the other hand, Sunday 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 33% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 5 weeks before departure.

Good to know

Low seasonDecember
Cheapest flight$59
Best time to beat the crowds with an average 4% drop in price.
Most popular time to fly with an average 11% increase in price.
Flight from St. Louis to Newark Liberty Airport

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.

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

    The cheapest time of day to fly to Pennsylvania is generally at night, when round-trip flights cost $404 on average. Morning departures are around 38% 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 $1,129.

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: New York $169 one-way - $293 round-trip; Philadelphia $345 one-way - $454 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 4268 reviews
8.6Crew
7.0Food
8.1Boarding
7.5Entertainment
8.0Comfort
Airline reviews

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

10.0 ExcellentAnonymous, Jan 2026
PHX - MDW
Read more Southwest reviews

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

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

Great vacation. Can't wait till next year for another one.

Great flight but super high price. Glad it was a business trip and not personal

On time. Friendly staff. Took to long to pre bord all the specialty groups. Cramped small plane

The seats were comfortable, and the boarding process was pretty smooth.

3 hour delay. Had to change plans and was still delayed.

The staff was very friendly, professional, and courteous. The overall flight was a great experience.

The crew canceled the complementary snack and drink in anticipation of turbulence that never materialized. I was counting on the drink (water) to take the the doses of medication - prescribed for my heart condition - that were due during the flight. Since no snack or meal was served on this flight, I cannot rate the food quality. Otherwise, this flight was excellent.

Departure was delayed more than 1/2 hour while we waited for luggage (only) transfer from another flight/plane. Once approved for takeoff, the flight was excellent.

The service from the flight attendants were of supreme quality. They greeted and treated everyone with a wide smile. This is totally absent nowadays. Kudos to them!!!!

Excellent flight and got us around tough weather. Only issue was seat TV did not work and crew tried to reboot.

Very large passenger too space from my own seat. Arm board couldn’t be lowered because of his size. It wads very uncomfortable trip, as the flight was full couldn’t move anywhere having back pain because of the position in which I was the entire flight.

was sitting in the jet bridge for 10 minutes in -20 degree weather waiting for my bag

Outdated equipment in disrepair, wifi inoperable. Broken seats, taped air vents, generally poor condition, the 717 showed its age and lack of upkeep.

My flight out of Baton Rouge to Atlanta was delayed by a half hour. This got us into Atlanta airport 30 minutes late. I ran through the airport to get to my connecting flight. As I approached the boarding gate, I saw the boarding door was still open and a passenger was being checked in. But when I got to the gate, the boarding agent told me they had already given away my seat and there were no empty seats on that flight. So I had to take a later flight. That has never happened to me before. Very frustrating.

Connection through Atlanta was difficult. Mechanical issue on plane caused a two hour delay. New gate was a mile away.

No WiFi. Comfort plus should have alcohol provided, crew only offered water or tea. Who the heck wants tea?

The flight was delayed and oversold. I volunteered to give up my seat for compensation. Thinking I could get a good night's sleep instead of arriving home at 2 am. It took over an hour to get the new reservation confirmed, three different gate attendants, and two red coats. It took even longer to confirm the overnight hotel, and when I arrived, the line was 45 minutes long, with two people checking in, and at least 15 people slowly, very slowly—no food except frozen convenience food, no coupon for food from airlines. Slept, headed back to the airport, and that flight had an equipment change and a gate change just as they were about to board. It took an additional hour to board as they cleaned the plane from storage.

There was no wifi available on this flight. And there were no screens, no onboard entertainment, no entertainment options at all. It was like travelling in the 1990s again, except without even a main screen for options. Seats, as usual, were tight and uncomfortable.

Seated dude next to me even though lots of empty rows. But main thing was we sat on the tarmac after landing for 30 minutes because of, in the words of the dude who sat next to me, “operational incompetence”. We got changing directions about where to pick up gate checked bags. Pilot and flight attendant were awesome though.

It was a pretty standard flight... until the almost hour and a half spent on the taxi way. I get that the weather has been poor but the delay had nothing to do with the weather and more to do with a plane with several issues tying up the gate. I get that that happens from time to time but this has been EVERY flight I've been on for the past 5 years and I fly 3 to 5 times a year. This isn't just United... it's American, it's Delta. It's an issue with the entire industry. I work for UPS and packages on a cargo plane get better service than people do these days. Anymore I HATE flying.

Flight arrived 30 min early and bag was waiting at the baggage pickup. United Club HNL was one of the nicest in the system

Unfortunately weather delayed our flight waiting for our plane to arrive and due to a little snow time was needed to deice the plane so departure was very delayed and I missed the connecting flight

Very good. Because of the delays with my previous flight, I missed my connection, but I was able to book another flight through the United app easily.

I wish there were outlets to charge my iPhone. The crew was great; we had a female pilot who was great with explaining what was happening and delays,

The flight crew where really good. Better then the crew from BNE to SFO

Delayed, toilets did not flush, pilot parked to far away from Gate

Was happy we finally got upgraded in 1st class. The seat getting old. The cushiness need some improvement.

Yet another flight in which beverage and snack service was skipped. Other that that, firmly mediocre. Landed early, to gate late due to congestion at the gates. Airline's fault or airports fault: unknown.

The attendants were kind and helpful. A sugar-free drink would have been very welcome.

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.

The entertainment options were at best, fair. It was exactly the same as my outbound flight. It would have been more entertaining if there were some series from Apple TV, HBO, Showtime or other carriers for me to catch up with.

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

The seat cushions were very worn so they were extremely uncomfortable.

Crew were all friendly and helpful. It was a short flight so just a beverage service with a cookie. After we were boarded the plane took about 45 minutes to leave the gate but it was New Year’s Eve so not shocking there was some delay. Overall good experience and very grateful.

Flight was on time is the only good thing. Person loading the plane called 1-6 to board at the same time, made it chaotic. Plane was too small for even putting backpacks in overhead. Seat for normal sized people were too small. The WIFI didn't work. When we landed had to wait because not enough ground crew.

the trip to madrid was uncomfortable with my legs touching the seat in front of me

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

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

Good for a budget airline! It was easy to get on, staff was really nice. Can’t say anything about the food or entertainment because it wasn’t available, which is fine.

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.

It was costly and difficult to check in. $85 to take a small suitcase with me, carry on or checked and $75 on the return trip, Plus $25 if I didn't check my self in check in $25, because I couldn't do it on the kiosk. Small very uncomfortable seats, waited on the runway for near an hour each way. It was my worst flight to date.

It was ok. It was expensive to check 2 bags ($75.00 per bag), and then it took a long time to wait for shuttle to take us from one terminal to the terminal where the plane was taking off at LAX. And all of this for a flight where we had to pay for any food or drink that was not water.

It didn’t happen. I booked it and then was told it wasn’t available and then forced to pay far higher prices for a worse option

A 630departure flight Delayed 6hours! They changed my gate, I moved to the new gate. Had our flight on the screen for 12noon departure. I go get above to eat, check screen again and the flight was gone, no notice no announcement, nothing!! They sent my bag on the flight I wasn’t on, got it back to me 3days later. Thank goodness they did refund my money but I will NEVER fly them again.

Due to weather, my flight was delayed, further delayed, then canceled. I eventually got through to a support person who helped me find a different route out of MSP, but to get to DIA, they didn't want to, but eventually did help with the connection ticket purchase. But even this replacement flight was delayed time and time again, and I would have missed my connecting flights and I didn't want to get stuck in a layover city, so after 12 hours at the airport with two young boys who were very tired, we just cancelled our plans and spent the week at home, instead of Nana's.

Plane and crew on board were fine. Everything else was terrible.

The third party booking with cheapflightsfares was awful. Kayak should NOT partner with them. They sold me a bundle including seat selection and carry-on, but did not book the carry-ons with Frontier, so I’m out of pocket for $414 more while I await resolution.

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

Information on your arrival and departure airports