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St. Louis

$48+ Cheap flights from Pennsylvania to St. Louis (STL)

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 1/21. Fares are subject to change and may not be available on all flights or dates of travel.
PHL — STL
Jan 7 — Jan 141
Wed 1/7
Wed 1/14
1 adult, Economy
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Cheap flight deals from Pennsylvania to St. Louis

Cheapest flights from Pennsylvania to St. Louis
Explore the most affordable flight options available from Pennsylvania to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 8, 2025.

This Mytrip deal was found by Cheapflights users on 12/7. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/1610:00 pmPHL - STL
1 stop25h 33mFrontier
Fri 12/199:07 amSTL - PHL
1 stop14h 06mFrontier
Deal found 12/7$196
This Frontier deal was found by Cheapflights users on 12/7. 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.
Wed 12/104:00 pmPHL - STL
1 stop7h 33mFrontier
Tue 12/163:30 pmSTL - PHL
1 stop8h 10mFrontier
Deal found 12/7$213
This Frontier deal was found by Cheapflights users on 12/5. 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.
Sun 12/215:10 amPHL - STL
1 stop5h 30mFrontier
Mon 12/224:27 pmSTL - PHL
1 stop7h 13mFrontier
Deal found 12/5$214
This Kiwi.com deal was found by Cheapflights users on 12/7. 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.
Tue 12/1612:20 pmPHL - STL
2 stops11h 13mFrontier
Thu 1/85:11 pmSTL - PHL
1 stop14h 26mFrontier
Deal found 12/7$216
This Kiwi.com deal was found by Cheapflights users on 12/7. 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.
Thu 12/188:00 amPHL - STL
1 stop15h 33mMultiple Airlines
Thu 1/83:43 pmSTL - PHL
2 stops22h 12mMultiple Airlines
Deal found 12/7$229
This Kiwi.com deal was found by Cheapflights users on 12/7. 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.
Tue 12/165:30 amPHL - STL
1 stop18h 03mMultiple Airlines
Tue 1/611:51 amSTL - PHL
1 stop10h 23mMultiple Airlines
Deal found 12/7$231
This Kiwi.com deal was found by Cheapflights users on 12/7. 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.
Tue 12/165:30 amPHL - STL
1 stop18h 03mMultiple Airlines
Wed 1/75:11 pmSTL - PHL
1 stop14h 26mMultiple Airlines
Deal found 12/7$234
This Frontier deal was found by Cheapflights users on 12/7. 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.
Wed 12/104:00 pmPHL - STL
1 stop7h 33mFrontier
Thu 12/1810:42 amSTL - PHL
1 stop5h 27mFrontier
Deal found 12/7$238
This Booking.com deal was found by Cheapflights users on 12/7. 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.
Sun 12/215:01 amPHL - STL
1 stop28h 11mFrontier
Wed 12/314:27 pmSTL - PHL
1 stop7h 13mFrontier
Deal found 12/7$241
This Frontier deal was found by Cheapflights users on 12/7. 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.
Mon 12/82:06 pmPHL - STL
1 stop9h 27mFrontier
Tue 12/163:30 pmSTL - PHL
1 stop8h 10mFrontier
Deal found 12/7$242
This Kiwi.com deal was found by Cheapflights users on 12/7. 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.
Wed 12/174:00 pmPHL - STL
1 stop7h 33mMultiple Airlines
Thu 1/83:43 pmSTL - PHL
2 stops22h 12mMultiple Airlines
Deal found 12/7$254
This Delta deal was found by Cheapflights users on 12/7. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/186:00 amMDT - STL
1 stop5h 45mDelta
Wed 12/315:55 pmSTL - MDT
1 stop4h 07mDelta
Deal found 12/7$259

Find flight deals from Pennsylvania to St. Louis

Keep the following information in mind while searching for Pennsylvania to St. Louis flight deals. Data was last updated December 8, 2025.

Most accurate provider

Gotogate
3 stars

Most trusted provider

Gotogate
3 stars

Round-trip from

$147
(Kiwi.com)

One-way from

$48
(Trip.com)

Popular in

May

Cheapest in

August

Average price

$452

Good round-trip deal

$348 or less

Good one-way deal

$197 or less
Provider with most accurate pricing for Philadelphia-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Philadelphia-Lambert-St Louis flights.
Search Deals
From Pennsylvania to Lambert-St Louis
Search Deals
One-way flight from Pennsylvania to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 8% potential increase in price ($36 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($7 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals
Price to beat on a round-trip flight from Pennsylvania to Lambert-St Louis.
Search Deals
Price to beat on a one-way flight from Pennsylvania to Lambert-St Louis.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Pennsylvania to St. Louis 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 December 8, 2025.
Use the filters below to find and compare flights from Pennsylvania to St. Louis that are best for you.

Fly from

Pennsylvania

Fly to

St. Louis

Route

Depart

Return

Price

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Thu 1/8

3:56 pm-10:33 pm

1 stop7h 37m

Lambert-St Louis

Thu 2/19

10:42 am-6:41 pm

1 stop6h 59m

$162

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Sat 1/17

4:08 pm-10:34 pm

1 stop7h 26m

Lambert-St Louis

Sat 1/24

11:00 am-10:46 pm

1 stop10h 46m

$164

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Sun 12/21

5:10 am-9:40 am

1 stop5h 30m

Lambert-St Louis

Mon 12/22

4:27 pm-12:40 am

1 stop7h 13m

$214

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Mon 1/12

3:56 pm-10:33 pm

1 stop7h 37m

Lambert-St Louis

Wed 1/14

8:32 pm-7:20 pm

2 stops21h 48m

$230

AllentownSt. Louis

ABE - STL

ABESTL

Allentown-Bethlehem

Wed 1/7

5:59 pm-11:39 pm

1 stop6h 40m

Lambert-St Louis

Wed 1/14

6:00 am-12:05 pm

1 stop5h 05m

$249

State CollegeSt. Louis

SCE - STL

SCESTL

State College University Park

Wed 2/18

10:00 am-9:41 pm

2 stops12h 41m

Lambert-St Louis

Sat 2/21

6:00 am-1:36 pm

1 stop6h 36m

$254

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Tue 1/13

6:05 am-10:15 am

1 stop5h 10m

Lambert-St Louis

Tue 1/20

6:20 am-3:25 pm

2 stops8h 05m

$256

HarrisburgSt. Louis

MDT - STL

MDTSTL

Harrisburg

Thu 12/18

5:00 am-8:35 am

1 stop4h 35m

Lambert-St Louis

Tue 12/30

4:53 pm-11:59 pm

1 stop6h 06m

$259

HarrisburgSt. Louis

MDT - STL

MDTSTL

Harrisburg

Thu 12/18

6:00 am-10:45 am

1 stop5h 45m

Lambert-St Louis

Wed 12/31

5:55 pm-11:02 pm

1 stop4h 07m

$259

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Sat 1/24

7:00 am-12:29 pm

1 stop6h 29m

Lambert-St Louis

Mon 1/26

8:30 am-2:04 pm

1 stop4h 34m

$261

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/6

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

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Pennsylvania 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 Pennsylvania to St. Louis

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

Currently, November is the cheapest month in which you can book a flight from Pennsylvania to St. Louis (average of $156). Flying from Pennsylvania to St. Louis in March is currently the most expensive (average of $238). 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 PA to STL?

Find hourly flight availability from Pennsylvania to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 8, 2025.

When flying from Pennsylvania to St. Louis, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 24% versus a flight at noon.

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

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

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

Weekly flight availability from Pennsylvania to St. Louis

Explore weekly flight availability from Pennsylvania to St. Louis. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated December 8, 2025.

The most flights from USPA to STL are scheduled on a Friday (12 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (8 on average).

Related info for your journey

Find useful and relevant information for your journey from Pennsylvania to St. Louis. 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 into for flights to St. Louis from Pennsylvania?

    Located just 12.7 mi from the city center, Lambert-St Louis (STL) is the airport most travelers will use when flying to St. Louis from Pennsylvania.

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

    Flights from Pennsylvania to Lambert-St Louis have been viewed 39 times in the past calendar month.

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

    Frontier, Delta, and American Airlines can get you from Pennsylvania to St. Louis in just under 6h 40m. Your travel time can differ by up to 6h 01m. There are 803 mi between Pennsylvania and St. Louis. 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 Pennsylvania to St. Louis one-way?

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $70. Users have also found prices from $80 and $89 on Spirit Airlines and American Airlines, respectively.

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

    While some choose either New York John F Kennedy Intl - Lambert-St Louis or New York LaGuardia - Lambert-St Louis, Newark - Lambert-St Louis is the most popular route from Pennsylvania to St. Louis.

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

    Consider Republic Airways (96%), American Airlines (87%) or Southwest (84%) when booking your flight. These represent the most reliable airlines when flying from Pennsylvania to St. Louis.

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

    The cheapest flight price from Pennsylvania to St. Louis is $144. On average you can expect to pay $338. The most popular route, (Newark - Lambert-St Louis), can usually be booked for $117.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Pennsylvania to St. Louis 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 Pennsylvania to St. Louis?

    Currently, November is the cheapest month in which you can book a flight from Pennsylvania to St. Louis (average of $156). Flying from Pennsylvania to St. Louis in March is currently the most expensive (average of $238). 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

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Swansea
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

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Alternative routes for Pennsylvania to St. Louis

See prices for flight routes from nearby airports that may be better suited for you.
LaGuardia to St. Louis flights
John F Kennedy Intl to Kansas City flights
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Top 6 airlines flying from Pennsylvania to St. Louis

Discover the top 6 airlines that operate flights from Pennsylvania to St. Louis. 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 December 8, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$95Average$178FlexibilityNo cancel feeOn-time65%
FrontierCheapest$130Average$233FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$171Average$341FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$241Average$381FlexibilityNo cancel feeOn-time63%
DeltaCheapest$242Average$335FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$248Average$372FlexibilityNo cancel feeOn-time69%

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