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St. Louis

$65+ 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 1/15. Fares are subject to change and may not be available on all flights or dates of travel.
PHL — STL
Oct 16 — Oct 231
Thu 10/16
Thu 10/23
1 adult, Economy
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Cheap 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 September 16, 2025.

Round-trip from

$135
(United Airlines)

One-way from

$65
(American Airlines)

Popular in

May

Cheapest in

August

Average price

$355

Good round-trip deal

$282 or less

Good one-way deal

$203 or less
From Pennsylvania to Lambert-St Louis
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One-way flight from Pennsylvania to Lambert-St Louis
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Highest demand for flights based on searches. 6% potential increase in price ($28 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($5 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from Pennsylvania to Lambert-St Louis.
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Price to beat on a one-way flight from Pennsylvania to Lambert-St Louis.
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Find 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 September 16, 2025.

This United Airlines deal was found by Cheapflights users on 9/14. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/87:05 amPIT - STL
1 stop4h 44mUnited Airlines
Wed 10/155:00 amSTL - PIT
1 stop4h 02mUnited Airlines
Deal found 9/14$135
This American Airlines deal was found by Cheapflights users on 9/14. 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.
Tue 10/285:40 amPIT - STL
1 stop5h 44mAmerican Airlines
Tue 11/46:00 amSTL - PIT
1 stop4h 51mAmerican Airlines
Deal found 9/14$159
This United Airlines deal was found by Cheapflights users on 9/14. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/232:11 pmPIT - STL
1 stop4h 28mUnited Airlines
Tue 12/25:27 pmSTL - PIT
1 stop5h 11mUnited Airlines
Deal found 9/14$164
This American Airlines deal was found by Cheapflights users on 9/14. 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.
Tue 10/712:26 pmPIT - STL
1 stop4h 44mAmerican Airlines
Mon 10/137:16 amSTL - PIT
1 stop8h 18mAmerican Airlines
Deal found 9/14$171
This American Airlines deal was found by Cheapflights users on 9/15. 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.
Tue 10/75:06 pmPIT - STL
1 stop7h 48mAmerican Airlines
Wed 10/86:00 amSTL - PIT
1 stop7h 42mAmerican Airlines
Deal found 9/15$183
This American Airlines deal was found by Cheapflights users on 9/16. 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.
Thu 10/97:17 amPIT - STL
1 stop7h 27mAmerican Airlines
Mon 10/136:00 amSTL - PIT
1 stop7h 42mAmerican Airlines
Deal found 9/16$184
This Delta deal was found by Cheapflights users on 9/14. 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.
Tue 10/76:00 amPIT - STL
1 stop5h 26mDelta
Fri 10/176:52 pmSTL - PIT
1 stop4h 40mDelta
Deal found 9/14$197
This American Airlines deal was found by Cheapflights users on 9/14. 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.
Tue 10/145:00 amDCA - STL
1 stop5h 37mAmerican Airlines
Tue 10/216:00 amSTL - DCA
Nonstop2h 10mAmerican Airlines
Deal found 9/14$204
This United Airlines deal was found by Cheapflights users on 9/14. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/97:05 amPIT - STL
1 stop6h 23mUnited Airlines
Wed 10/1512:25 pmSTL - PIT
1 stop4h 51mUnited Airlines
Deal found 9/14$205
This American Airlines deal was found by Cheapflights users on 9/14. 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.
Sat 10/115:30 pmDCA - STL
1 stop7h 28mAmerican Airlines
Tue 10/1410:54 amSTL - DCA
Nonstop2h 05mAmerican Airlines
Deal found 9/14$207
This Booking.com deal was found by Cheapflights users on 9/15. 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.
Fri 10/106:59 amJFK - STL
1 stop11h 11mFrontier
Tue 10/147:52 pmSTL - JFK
1 stop15h 09mFrontier
Deal found 9/15$208
This Booking.com deal was found by Cheapflights users on 9/15. 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.
Sat 9/2710:56 pmLGA - STL
1 stop11h 10mFrontier
Tue 9/307:55 pmSTL - LGA
1 stop25h 16mFrontier
Deal found 9/15$209

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 September 16, 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

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Sun 11/23

2:11 pm-5:39 pm

1 stop4h 28m

Lambert-St Louis

Tue 12/2

5:27 pm-11:38 pm

1 stop5h 11m

$164

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Wed 10/8

10:24 am-1:22 pm

1 stop3h 58m

Lambert-St Louis

Tue 10/14

6:14 pm-11:03 pm

1 stop3h 49m

$197

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Tue 10/7

6:00 am-10:26 am

1 stop5h 26m

Lambert-St Louis

Wed 10/15

6:00 am-12:43 pm

1 stop5h 43m

$197

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Wed 10/8

10:02 am-3:55 pm

1 stop6h 53m

Lambert-St Louis

Mon 10/13

5:15 pm-12:32 am

1 stop6h 17m

$197

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Thu 12/4

12:00 pm-5:57 pm

1 stop6h 57m

Lambert-St Louis

Sun 12/7

6:40 am-11:12 am

1 stop3h 32m

$197

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Sat 10/11

4:59 pm-10:04 pm

1 stop6h 05m

Lambert-St Louis

Thu 10/16

6:40 am-11:10 am

1 stop3h 30m

$197

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Tue 11/4

1:44 pm-6:25 pm

1 stop5h 41m

Lambert-St Louis

Fri 11/7

1:50 pm-4:58 pm

Nonstop2h 08m

$204

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Tue 10/14

7:00 am-9:07 am

1 stop27h 07m

Lambert-St Louis

Fri 10/24

7:52 pm-12:04 pm

1 stop15h 12m

$217

New YorkSt. Louis

LGA - STL

LGASTL

New York LaGuardia

Thu 11/20

6:30 pm-8:20 pm

Nonstop2h 50m

Lambert-St Louis

Tue 12/2

7:55 pm-11:10 pm

Nonstop2h 15m

$219

New YorkSt. Louis

LGA - STL

LGASTL

New York LaGuardia

Thu 11/13

2:05 pm-8:15 pm

1 stop7h 10m

Lambert-St Louis

Sat 11/15

1:45 pm-10:20 pm

2 stops7h 35m

$222

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/15

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, August is the cheapest month in which you can book a flight from Pennsylvania to St. Louis (average of $311). Flying from Pennsylvania to St. Louis in March is currently the most expensive (average of $356). 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 September 16, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Pennsylvania to St. Louis as you normally would.

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 36 times in the past calendar month.

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

    United Airlines, Delta, and American Airlines can get you from Pennsylvania to St. Louis in just under 3h 58m. Your travel time can differ by up to 1h 43m. There are 552 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 United Airlines. According to our data, you can fly for as low as $68. Users have also found prices from $83 and $99 on Frontier and Delta, respectively.

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

    While some choose either New York LaGuardia - Lambert-St Louis or Newark - Lambert-St Louis, New York John F Kennedy Intl - 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 (100%), Southwest (72%) or American Airlines (70%) 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 $146. On average you can expect to pay $307. The most popular route, (New York John F Kennedy Intl - Lambert-St Louis), can usually be booked for $197.

  • 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, August is the cheapest month in which you can book a flight from Pennsylvania to St. Louis (average of $311). Flying from Pennsylvania to St. Louis in March is currently the most expensive (average of $356). 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
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.
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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 September 16, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$95Average$178FlexibilityNo cancel feeOn-time65%
FrontierCheapest$119Average$236FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$177Average$343FlexibilityNo cancel feeOn-time71%
DeltaCheapest$238Average$359FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$241Average$382FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$248Average$408FlexibilityNo cancel feeOn-time69%

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