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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 12/21. Fares are subject to change and may not be available on all flights or dates of travel.
PHL — STL
nov. 22 — nov. 291
sáb. 11/22
sáb. 11/29
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 octubre 23, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$159
(American Airlines)

One-way from

$48
(Kiwi.com)

Popular in

May

Cheapest in

September

Average price

$398

Good round-trip deal

$352 or less

Good one-way deal

$178 or less
Provider with most accurate pricing for Philadelphia-Lambert-St Louis flight deals.
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Provider most trusted by Cheapflights users for Philadelphia-Lambert-St Louis flights.
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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 ($27 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 October 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 octubre 23, 2025.

This American Airlines deal was found by Cheapflights users on 10/21. 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. 12/41:49 pmPIT - STL
1 stop6h 41mAmerican Airlines
dom. 12/76:53 pmSTL - PIT
1 stop4h 42mAmerican Airlines
Deal found 10/21$159
This Delta deal was found by Cheapflights users on 10/21. 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.
mar. 12/237:40 pmPIT - STL
1 stop5h 02mDelta
lun. 1/55:45 pmSTL - PIT
1 stop3h 56mDelta
Deal found 10/21$177
This Kiwi.com deal was found by Cheapflights users on 10/21. 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.
dom. 11/910:15 amPIT - STL
1 stop8h 01mMultiple Airlines
vie. 11/144:56 pmSTL - PIT
2 stops12h 25mMultiple Airlines
Deal found 10/21$228
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
dom. 11/26:45 pmPIT - STL
1 stop15h 55mMultiple Airlines
jue. 11/67:02 pmSTL - PIT
1 stop25h 09mMultiple Airlines
Deal found 10/20$229
This United Airlines deal was found by Cheapflights users on 10/22. 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.
jue. 12/410:30 amDCA - STL
1 stop6h 10mUnited Airlines
dom. 12/76:42 pmSTL - DCA
1 stop4h 17mUnited Airlines
Deal found 10/22$237
This Kiwi.com deal was found by Cheapflights users on 10/21. 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.
mié. 11/198:40 amIAD - STL
1 stop15h 21mMultiple Airlines
dom. 11/2311:08 amSTL - IAD
2 stops25h 08mMultiple Airlines
Deal found 10/21$238
This American Airlines deal was found by Cheapflights users on 10/22. 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. 12/47:59 pmDCA - STL
Nonstop2h 48mAmerican Airlines
dom. 12/75:15 amSTL - DCA
1 stop6h 31mAmerican Airlines
Deal found 10/22$238
This CheapOair deal was found by Cheapflights users on 10/23. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 11/158:36 pmIAD - STL
1 stop17h 41mFrontier
sáb. 11/224:13 pmSTL - IAD
1 stop14h 32mFrontier
Deal found 10/23$239
This Delta deal was found by Cheapflights users on 10/22. 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.
mié. 11/126:00 amMDT - STL
1 stop5h 43mDelta
lun. 11/176:09 pmSTL - MDT
1 stop3h 55mDelta
Deal found 10/22$239
This Frontier deal was found by Cheapflights users on 10/23. 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.
lun. 12/155:45 amIAD - STL
1 stop5h 07mFrontier
lun. 12/2210:40 amSTL - IAD
1 stop9h 33mFrontier
Deal found 10/23$240
This United Airlines deal was found by Cheapflights users on 10/22. 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.
vie. 12/58:30 amDCA - STL
1 stop6h 53mUnited Airlines
dom. 12/76:42 pmSTL - DCA
1 stop4h 17mUnited Airlines
Deal found 10/22$240
This Kiwi.com deal was found by Cheapflights users on 10/21. 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.
mié. 10/2911:26 amEWR - STL
1 stop23h 46mFrontier
jue. 10/302:12 pmSTL - EWR
2 stops9h 54mFrontier
Deal found 10/21$240

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 octubre 23, 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

mar. 12/23

7:40 pm-11:42 pm

1 stop5h 02m

Lambert-St Louis

lun. 1/5

5:45 pm-10:41 pm

1 stop3h 56m

$177

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

vie. 2/6

8:30 am-7:41 pm

1 stop12h 11m

Lambert-St Louis

lun. 2/9

8:45 am-10:37 pm

2 stops12h 52m

$233

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

jue. 12/4

10:30 am-3:40 pm

1 stop6h 10m

Lambert-St Louis

dom. 12/7

6:42 pm-11:59 pm

1 stop4h 17m

$237

HarrisburgSt. Louis

MDT - STL

MDTSTL

Harrisburg

sáb. 11/22

5:00 am-8:27 am

1 stop4h 27m

Lambert-St Louis

vie. 11/28

3:43 pm-11:38 pm

1 stop6h 55m

$239

HarrisburgSt. Louis

MDT - STL

MDTSTL

Harrisburg

mié. 11/12

6:00 am-10:43 am

1 stop5h 43m

Lambert-St Louis

lun. 11/17

6:09 pm-11:04 pm

1 stop3h 55m

$239

HarrisburgSt. Louis

MDT - STL

MDTSTL

Harrisburg

sáb. 11/15

6:00 am-12:26 pm

1 stop7h 26m

Lambert-St Louis

lun. 11/17

5:17 pm-11:11 pm

1 stop4h 54m

$239

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

mar. 12/2

10:08 am-4:06 pm

1 stop6h 58m

Lambert-St Louis

vie. 12/5

5:12 pm-12:12 am

1 stop6h 00m

$242

AllentownSt. Louis

ABE - STL

ABESTL

Allentown-Bethlehem

sáb. 12/13

5:14 pm-9:28 pm

1 stop5h 14m

Lambert-St Louis

mié. 12/17

10:13 am-3:53 pm

1 stop4h 40m

$243

HarrisburgSt. Louis

MDT - STL

MDTSTL

Harrisburg

lun. 11/17

4:25 pm-11:07 pm

1 stop7h 42m

Lambert-St Louis

lun. 11/24

4:46 pm-11:38 pm

1 stop5h 52m

$249

AllentownSt. Louis

ABE - STL

ABESTL

Allentown-Bethlehem

sáb. 4/4

5:40 pm-11:40 pm

1 stop7h 00m

Lambert-St Louis

mié. 4/8

10:00 am-5:13 pm

1 stop6h 13m

$249

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/22

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, December is the cheapest month in which you can book a flight from Pennsylvania to St. Louis (average of $167). Flying from Pennsylvania to St. Louis in March is currently the most expensive (average of $240). 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 octubre 23, 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 afternoon, which can drop the price by up to 20% 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. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

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 34 times in the past calendar month.

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

    Delta, United Airlines, and American Airlines can get you from Pennsylvania to St. Louis in just under 4h 27m. Your travel time can differ by up to 1h 43m. There are 731 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 Southwest. According to our data, you can fly for as low as $85. Users have also found prices from $88 and $89 on United Airlines and Delta, respectively.

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

    While some choose either Newark - Lambert-St Louis or New York LaGuardia - 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 (84%) or American Airlines (76%) 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 $135. On average you can expect to pay $319. The most popular route, (New York John F Kennedy Intl - Lambert-St Louis), can usually be booked for $193.

  • 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, December is the cheapest month in which you can book a flight from Pennsylvania to St. Louis (average of $167). Flying from Pennsylvania to St. Louis in March is currently the most expensive (average of $240). 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

Browse thousands of different options on Cheapflights for your next trip

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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 octubre 23, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$119Average$237FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$144Average$183FlexibilityNo cancel feeOn-time65%
American AirlinesCheapest$171Average$344FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$243Average$384FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$248Average$412FlexibilityNo cancel feeOn-time69%
DeltaCheapest$248Average$349FlexibilityNo cancel feeOn-timeN/A

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