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St. Louis

$59+ 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 6/28. Fares are subject to change and may not be available on all flights or dates of travel.
PHL — STL
Jun 7 — Jun 141
Sun 6/7
Sun 6/14
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 May 8, 2026.

This United Airlines deal was found by Cheapflights users on 5/6. 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.
Sat 5/308:36 am
PIT
-
STL
1 stop4h 31m
United Airlines
Sat 6/66:00 am
STL
-
PIT
1 stop6h 07m
United Airlines
Deal found 5/6$197
This United Airlines deal was found by Cheapflights users on 5/6. 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 6/46:49 am
PIT
-
STL
1 stop6h 22m
United Airlines
Sat 6/68:00 am
STL
-
PIT
1 stop4h 07m
United Airlines
Deal found 5/6$225
This American Airlines deal was found by Cheapflights users on 5/7. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/48:42 pm
PIT
-
STL
1 stop4h 34m
American Airlines
Thu 6/116:00 am
STL
-
PIT
1 stop4h 40m
American Airlines
Deal found 5/7$236
This Southwest deal was found by Cheapflights users on 5/4. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/37:10 pm
PIT
-
STL
Nonstop1h 50m
Southwest
Wed 6/1010:25 am
STL
-
PIT
Nonstop1h 35m
Southwest
Deal found 5/4$237
This Mytrip deal was found by Cheapflights users on 5/7. 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.
Fri 5/298:15 pm
PIT
-
STL
1 stop28h 42m
Frontier
Mon 6/111:24 am
STL
-
PIT
1 stop6h 56m
Frontier
Deal found 5/7$239
This Kiwi.com deal was found by Cheapflights users on 5/7. 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 6/45:55 am
EWR
-
STL
1 stop12h 38m
Frontier
Mon 6/85:27 pm
STL
-
EWR
2 stops16h 04m
Frontier
Deal found 5/7$239
This Expedia deal was found by Cheapflights users on 5/7. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/2610:29 pm
EWR
-
STL
1 stop11h 26m
Frontier
Thu 6/46:33 pm
STL
-
EWR
1 stop5h 45m
Frontier
Deal found 5/7$240
This Kiwi.com deal was found by Cheapflights users on 5/6. 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 8/185:55 am
EWR
-
STL
1 stop12h 35m
Frontier
Sat 8/225:33 pm
STL
-
EWR
1 stop26h 56m
Frontier
Deal found 5/6$241
This Kiwi.com deal was found by Cheapflights users on 5/6. 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.
Fri 6/510:29 pm
EWR
-
STL
1 stop11h 26m
Frontier
Mon 6/85:27 pm
STL
-
EWR
1 stop6h 51m
Frontier
Deal found 5/6$243
This Kiwi.com deal was found by Cheapflights users on 5/6. 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 5/285:55 am
EWR
-
STL
1 stop12h 38m
Frontier
Mon 6/15:27 pm
STL
-
EWR
1 stop27h 02m
Frontier
Deal found 5/6$244
This CheapOair deal was found by Cheapflights users on 5/6. 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.
Sat 5/238:35 pm
PHL
-
STL
1 stop23h 48m
Frontier
Thu 5/286:33 pm
STL
-
PHL
1 stop11h 39m
Frontier
Deal found 5/6$244
This Flightnetwork deal was found by Cheapflights users on 5/6. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/1210:29 pm
EWR
-
STL
1 stop11h 23m
Frontier
Mon 6/154:17 pm
STL
-
EWR
1 stop17h 13m
Frontier
Deal found 5/6$246

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 May 8, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$197
(United Airlines)

One-way from

$59
(Trip.com)

Popular in

December

Cheapest in

September

Average price

$450

Good round-trip deal

$374 or less

Good one-way deal

$178 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. 3% potential increase in price ($16 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in May 2026
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 May 8, 2026.
Use the filters below to find and compare flights from Pennsylvania to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip
Quickest round-trip

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Tue 7/7

6:45 am-7:30 am

Nonstop1h 45m

Lambert-St Louis

Tue 7/14

7:10 pm-9:45 pm

Nonstop1h 35m

$257

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Wed 8/12

2:45 pm-4:05 pm

Nonstop2h 20m

Lambert-St Louis

Tue 8/25

6:40 pm-9:50 pm

Nonstop2h 10m

$257

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Thu 5/28

2:45 pm-4:05 pm

Nonstop2h 20m

Lambert-St Louis

Mon 6/1

7:40 pm-10:40 pm

Nonstop2h 00m

$265

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Sat 8/15

6:40 pm-7:50 pm

Nonstop2h 10m

Lambert-St Louis

Mon 8/17

1:10 pm-4:10 pm

Nonstop2h 00m

$265

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Sat 5/30

7:15 am-8:05 am

Nonstop1h 50m

Lambert-St Louis

Sat 6/6

4:45 pm-12:35 am

1 stop6h 50m

$270

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 5/28

6:08 am-12:20 pm

1 stop7h 12m

Lambert-St Louis

Tue 6/2

1:27 pm-6:43 pm

1 stop4h 16m

$271

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Tue 5/26

6:20 am-7:45 am

Nonstop2h 25m

Lambert-St Louis

Sat 5/30

6:55 pm-10:05 pm

Nonstop2h 10m

$274

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Mon 8/24

6:50 pm-8:00 pm

Nonstop2h 10m

Lambert-St Louis

Thu 8/27

3:15 pm-10:45 pm

1 stop6h 30m

$275

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Wed 6/3

6:10 am-12:11 pm

1 stop7h 01m

Lambert-St Louis

Wed 6/3

5:29 pm-12:59 am

1 stop6h 30m

$277

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Tue 6/2

8:51 am-12:11 pm

1 stop4h 20m

Lambert-St Louis

Wed 6/3

7:22 am-3:23 pm

1 stop7h 01m

$277

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/3

Showing 1-10 of 60 resultsSorted by cheapest first
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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

How far ahead should I book a flight from Pennsylvania to St. Louis?

To ensure you get the cheapest price possible for a flight from Pennsylvania to St. Louis, you should look to book at least 57 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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

Currently, July is the cheapest month in which you can book a flight from Pennsylvania to St. Louis (average of $93). Flying from Pennsylvania to St. Louis in March is currently the most expensive (average of $264). 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 May 8, 2026.

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 14% versus a flight in the morning.

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 May 2, 2026.

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

How much does it cost to fly round-trip from Pennsylvania to St. Louis?

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 40 times in the past calendar month.

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

    Southwest, Delta, and United Airlines can get you from Pennsylvania to St. Louis in just under 1h 45m. Your travel time can differ by up to 5h 27m. 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 Frontier. According to our data, you can fly for as low as $61. Users have also found prices from $80 and $108 on Spirit Airlines and Southwest, respectively.

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

    While some choose either New York LaGuardia - Lambert-St Louis or New York John F Kennedy Intl - 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 (100%), Qatar Airways (89%) or Southwest (81%) 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 $138. On average you can expect to pay $373. The most popular route, (Newark - Lambert-St Louis), can usually be booked for $267.

  • 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, July is the cheapest month in which you can book a flight from Pennsylvania to St. Louis (average of $93). Flying from Pennsylvania to St. Louis in March is currently the most expensive (average of $264). 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
Fenton
Swansea
Fairview Heights
Maryland Heights
Collinsville
Eureka
Wentzville
Glencoe
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.
Newark to St. Louis flights
Newark to Kansas City flights
Los Angeles to Kansas City flights
LaGuardia to Kansas City flights
John F Kennedy Intl to Kansas City flights
Denver to St. Louis flights
LaGuardia to St. Louis flights
John F Kennedy Intl to St. Louis flights
Dulles Intl to St. Louis flights
Denver to Kansas City flights
Dallas/Fort Worth to St. Louis flights
Dulles Intl to Kansas City flights
Los Angeles to St. Louis flights
Seattle to Kansas City flights
O'Hare Intl to Kansas City flights
Boston to St. Louis flights
San Francisco to Kansas City flights
Boston to Kansas City flights
Reagan-National to St. Louis flights
Baltimore to St. Louis flights
Dallas/Fort Worth to Kansas City flights
Orlando to St. Louis flights
Hobby to Kansas City flights
Seattle to St. Louis flights
Atlanta to St. Louis flights
Philadelphia to St. Louis flights
Orlando to Kansas City flights
San Francisco to St. Louis flights
Baltimore to Kansas City flights
Hobby to St. Louis flights
Miami to Kansas City flights
Ontario to Kansas City flights
Fort Lauderdale to Kansas City flights
Reagan-National to Kansas City flights
Minneapolis to Kansas City flights
George Bush Intcntl to Kansas City flights
Denver to Springfield flights
O'Hare Intl to St. Louis flights
George Bush Intcntl to St. Louis flights
Miami to St. Louis flights
Philadelphia to Kansas City flights
Sky Harbor Intl to St. Louis flights
Las Vegas to St. Louis flights
Tampa to Kansas City flights
Sky Harbor Intl to Kansas City flights
Atlanta to Kansas City flights
San Diego to St. Louis flights
Raleigh to St. Louis flights
Portland to Kansas City flights
Fort Lauderdale to St. Louis flights

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 May 8, 2026.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$93Average$178FlexibilityNo cancel feeOn-time65%
FrontierCheapest$128Average$221FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$170Average$343FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$221Average$393FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$248Average$391FlexibilityNo cancel feeOn-time69%
DeltaCheapest$248Average$401FlexibilityNo cancel feeOn-timeN/A

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