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$55+ Cheap flights from St. Louis (STL) to Pennsylvania

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/15. Fares are subject to change and may not be available on all flights or dates of travel.
STL — PHL
nov. 27 — dic. 41
jue. 11/27
jue. 12/4
1 adult, Economy
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Find flight deals from St. Louis to Pennsylvania

Cheapest flights from St. Louis to Pennsylvania
Explore the most affordable flight options available from St. Louis to Pennsylvania. Find the lowest fares from popular airlines and budget airlines, with prices last updated on octubre 28, 2025.

This Priceline deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/127:45 pmSTL - PHL
1 stop8h 04mFrontier
lun. 11/175:05 amPHL - STL
1 stop9h 12mFrontier
Deal found 10/27$110
This Booking.com deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 11/132:12 pmSTL - PHL
1 stop20h 14mFrontier
mar. 11/186:50 pmPHL - STL
1 stop16h 15mFrontier
Deal found 10/27$111
This Frontier deal was found by Cheapflights users on 10/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/127:45 pmSTL - PHL
1 stop8h 04mFrontier
dom. 11/1610:32 pmPHL - STL
1 stop12h 08mFrontier
Deal found 10/26$143
This American Airlines deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 12/46:00 pmSTL - PIT
1 stop4h 07mAmerican Airlines
lun. 12/86:00 amPIT - STL
1 stop4h 32mAmerican Airlines
Deal found 10/27$159
This Trip.com deal was found by Cheapflights users on 10/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/197:24 pmSTL - PHL
1 stop18h 40mMultiple Airlines
vie. 11/218:54 pmPHL - STL
1 stop13h 03mMultiple Airlines
Deal found 10/28$165
This Frontier deal was found by Cheapflights users on 10/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 12/43:30 pmSTL - PHL
1 stop8h 10mFrontier
lun. 12/82:06 pmPHL - STL
1 stop9h 27mFrontier
Deal found 10/26$170
This American Airlines deal was found by Cheapflights users on 10/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 12/256:00 amSTL - PIT
1 stop10h 09mAmerican Airlines
jue. 1/18:15 amPIT - STL
1 stop6h 21mAmerican Airlines
Deal found 10/26$175
This Frontier deal was found by Cheapflights users on 10/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 11/611:07 amSTL - PHL
1 stop6h 37mFrontier
dom. 11/95:50 amPHL - STL
1 stop5h 22mFrontier
Deal found 10/28$176
This Booking.com deal was found by Cheapflights users on 10/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/57:45 pmSTL - PHL
1 stop8h 04mFrontier
sáb. 11/86:19 amPHL - STL
1 stop27h 48mFrontier
Deal found 10/28$178
This Kiwi.com deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 11/137:02 pmSTL - PHL
1 stop13h 28mMultiple Airlines
mar. 11/186:50 pmPHL - STL
2 stops29h 11mMultiple Airlines
Deal found 10/27$186
This Kiwi.com deal was found by Cheapflights users on 10/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 12/2210:40 amSTL - IAD
1 stop9h 23mFrontier
sáb. 12/277:11 pmIAD - STL
1 stop15h 29mFrontier
Deal found 10/25$197
This Frontier deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 11/611:07 amSTL - PHL
1 stop6h 37mFrontier
sáb. 11/88:00 amPHL - STL
1 stop8h 38mFrontier
Deal found 10/27$202

Cheap flight deals from St. Louis to Pennsylvania

Keep the following information in mind while searching for St. Louis to Pennsylvania flight deals. Data was last updated octubre 28, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$110
(Priceline)

One-way from

$55
(Priceline)

Popular in

March

Cheapest in

August

Average price

$392

Good round-trip deal

$263 or less

Good one-way deal

$169 or less
Provider with most accurate pricing for Lambert-St Louis-Philadelphia flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Philadelphia flights.
Search Deals
From Lambert-St Louis to Pennsylvania
Search Deals
One-way flight from Lambert-St Louis to Pennsylvania
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($20 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($5 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 2025
Search Deals
Price to beat on a round-trip flight from Lambert-St Louis to Pennsylvania.
Search Deals
Price to beat on a one-way flight from Lambert-St Louis to Pennsylvania.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Pennsylvania that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated octubre 28, 2025.
Use the filters below to find and compare flights from St. Louis to Pennsylvania that are best for you.

Fly from

St. Louis

Fly to

Pennsylvania

Route

Depart

Return

Price

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

mié. 11/12

7:45 pm-4:49 am

1 stop8h 04m

Philadelphia

dom. 11/16

10:32 pm-9:40 am

1 stop12h 08m

$143

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

vie. 1/9

7:43 pm-10:31 am

2 stops13h 48m

Philadelphia

lun. 1/12

10:00 pm-10:37 pm

1 stop25h 37m

$157

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

lun. 12/22

10:40 am-8:37 am

1 stop20h 57m

Philadelphia

dom. 1/4

5:10 am-9:40 am

1 stop5h 30m

$233

St. LouisPittsburgh

STL - PIT

STLPIT

Lambert-St Louis

vie. 11/7

10:35 am-5:51 pm

1 stop6h 16m

Pittsburgh

dom. 11/9

7:08 pm-9:40 am

1 stop15h 32m

$234

St. LouisPittsburgh

STL - PIT

STLPIT

Lambert-St Louis

jue. 12/4

7:12 am-12:59 pm

1 stop4h 47m

Pittsburgh

lun. 12/8

6:00 am-9:32 am

1 stop4h 32m

$239

St. LouisHarrisburg

STL - MDT

STLMDT

Lambert-St Louis

mié. 11/12

11:39 am-6:16 pm

1 stop5h 37m

Harrisburg

sáb. 11/15

6:00 am-12:26 pm

1 stop7h 26m

$249

St. LouisHarrisburg

STL - MDT

STLMDT

Lambert-St Louis

sáb. 11/15

5:00 am-11:06 am

1 stop5h 06m

Harrisburg

sáb. 11/22

5:00 am-8:27 am

1 stop4h 27m

$249

St. LouisHarrisburg

STL - MDT

STLMDT

Lambert-St Louis

vie. 12/12

6:05 pm-11:07 pm

1 stop4h 02m

Harrisburg

dom. 12/14

6:00 am-10:45 am

1 stop5h 45m

$249

St. LouisHarrisburg

STL - MDT

STLMDT

Lambert-St Louis

jue. 12/18

6:35 pm-12:19 am

1 stop4h 44m

Harrisburg

vie. 1/2

8:00 am-2:20 pm

1 stop7h 20m

$249

St. LouisHarrisburg

STL - MDT

STLMDT

Lambert-St Louis

mié. 2/18

10:00 am-5:25 pm

1 stop6h 25m

Harrisburg

sáb. 2/21

6:10 am-9:44 am

1 stop4h 34m

$249

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/26

Showing 1-10 of 60 results
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Best time to book a flight from St. Louis to Pennsylvania

Have a flexible travel schedule? Discover the best time to fly to Pennsylvania from St. Louis with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

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

What is the cheapest month to book a flight from St. Louis to Pennsylvania?

Currently, August is the cheapest month in which you can book a flight from St. Louis to Pennsylvania (average of $151). Flying from St. Louis to Pennsylvania in June is currently the most expensive (average of $244). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from STL to PA?

Find hourly flight availability from St. Louis to Pennsylvania. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated octubre 28, 2025.

It’s optimal to fly from St. Louis to Pennsylvania in the morning. By choosing this option you can save up to 27% on the cost of your flight, compared to a flight at noon.

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

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Pennsylvania. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their St. Louis to Pennsylvania flight should consider departing on Thursday at noon when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Reviews of airlines servicing Pennsylvania

Get insights into the airlines that provide service to Pennsylvania. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Pennsylvania. Reviews last updated octubre 28, 2025.
Get a feel of what it's like to fly with Southwest, Delta, and United Airlines from St. Louis to Pennsylvania by reading reviews from past customers. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,240 reviews

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Southwest
8.0
Very good
4,240 reviews
Southwest
8.0
Very good
4,240 reviews

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Delta
7.9
Good
7,994 reviews
Southwest
8.0
Very good
4,240 reviews

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
United Airlines
7.4
Good
9,001 reviews
Southwest
8.0
Very good
4,240 reviews

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
American Airlines
7.2
Good
11,032 reviews
Southwest
8.0
Very good
4,240 reviews

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Frontier
5.8
Fair
3,124 reviews
Southwest
8.0
Very good
4,240 reviews

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Pennsylvania. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from St. Louis to Pennsylvania?

    If you book a flight to Pennsylvania from St. Louis, you will be flying from Lambert-St Louis, which is the city’s only airport. Lambert-St Louis (STL) is located 12.7 mi from the center of St. Louis.

  • How popular is this St. Louis to Pennsylvania flight route?

    Within the past month, 16 users have taken a look at flights from Lambert-St Louis to Pennsylvania.

  • How long is the flight from St. Louis to Pennsylvania?

    Frontier, American Airlines, and Delta can get you from St. Louis to Pennsylvania in just under 4h 47m. Your travel time can differ by up to 3h 17m. St. Louis and Pennsylvania are separated by a distance of 552 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the cheapest airlines to fly from St. Louis to Pennsylvania one-way?

    $79 is the cheapest one-way deal found within the past few days, from Southwest. You may also be able to find cheap deals on Frontier and Spirit Airlines, with prices starting from $81 and $90, respectively.

  • What are the most popular routes from St. Louis to Pennsylvania?

    The most popular flight routes from St. Louis to Pennsylvania are Lambert-St Louis - New York LaGuardia, Lambert-St Louis - Newark and Lambert-St Louis - New York John F Kennedy Intl.

  • What are the most reliable airlines from St. Louis to Pennsylvania?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from St. Louis to Pennsylvania on time: British Airways (91%), Qatar Airways (84%), Southwest (73%).

  • What are the cheapest flights from St. Louis to Pennsylvania?

    While on average a flight from St. Louis to Pennsylvania is generally $679, our data shows the cheapest flight currently is $176. When looking at the most popular route, (Lambert-St Louis - New York LaGuardia), you can expect to pay $143 for that flight.

  • Can I find deals for flights from St. Louis to Pennsylvania that include hotel bookings?

    Yes. In addition to deals on St. Louis to Pennsylvania flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Pennsylvania?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Pennsylvania.

  • Can I find deals for business class flights from St. Louis to Pennsylvania?

    Yes. Cheapflights offers flight deals from St. Louis to Pennsylvania by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from St. Louis to Pennsylvania?

    Currently, August is the cheapest month in which you can book a flight from St. Louis to Pennsylvania (average of $151). Flying from St. Louis to Pennsylvania in June is currently the most expensive (average of $244). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

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Alternative routes for St. Louis to Pennsylvania

See prices for flight routes from nearby airports that may be better suited for you.
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Top 6 airlines flying from St. Louis to Pennsylvania

Discover the top 6 airlines that operate flights from St. Louis to Pennsylvania. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated octubre 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$106Average$219FlexibilityNo cancel feeOn-time65%
FrontierCheapest$137Average$231FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$228Average$389FlexibilityNo cancel feeOn-time71%
DeltaCheapest$242Average$393FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$248Average$395FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$248Average$393FlexibilityNo cancel feeOn-time69%

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