St. Louis

$64+ Cheap flights from Philadelphia to St. Louis (PHL - 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 3/3. Fares are subject to change and may not be available on all flights or dates of travel.
PHL — STL
Feb 28 — Mar 71
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Find cheap flights from Philadelphia to St. Louis with Cheapflights

1. Tell us where you want to go

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2. Select your favorite providers

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Cheapflights Tip: The best prices from Philadelphia to Lambert-St Louis are usually found in August or September, booked 87 days in advance, depart on a Wednesday or Thursday and return on a Thursday

Cheap flight deals from Philadelphia to St. Louis

Cheapest flights from Philadelphia to St. Louis
Explore the most affordable flight options available from Philadelphia to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 29, 2026.

This Expedia deal was found by Cheapflights users on 1/27. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/234:29 pm
PHL
-
STL
1 stop8h 30m
Frontier
Wed 2/253:49 pm
STL
-
PHL
1 stop29h 04m
Frontier
Deal found 1/27$138
This Kiwi.com deal was found by Cheapflights users on 1/28. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/57:04 pm
PHL
-
STL
1 stop12h 47m
Frontier
Fri 2/68:22 pm
STL
-
PHL
1 stop13h 56m
Frontier
Deal found 1/28$151
This Kiwi.com deal was found by Cheapflights users on 1/27. 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.
Tue 3/34:14 pm
PHL
-
STL
1 stop7h 13m
Frontier
Fri 3/61:09 pm
STL
-
PHL
1 stop10h 43m
Frontier
Deal found 1/27$155
This Kiwi.com deal was found by Cheapflights users on 1/28. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/15:30 am
PHL
-
STL
1 stop26h 21m
Frontier
Wed 3/48:17 pm
STL
-
PHL
1 stop13h 10m
Frontier
Deal found 1/28$158
This Kiwi.com deal was found by Cheapflights users on 1/27. 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.
Fri 2/67:04 pm
PHL
-
STL
1 stop12h 47m
Frontier
Sun 2/85:42 pm
STL
-
PHL
1 stop14h 39m
Frontier
Deal found 1/27$160
This Kiwi.com deal was found by Cheapflights users on 1/27. 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.
Tue 3/38:06 am
PHL
-
STL
2 stops15h 21m
Multiple Airlines
Fri 3/61:09 pm
STL
-
PHL
1 stop10h 43m
Multiple Airlines
Deal found 1/27$167
This Kiwi.com deal was found by Cheapflights users on 1/27. 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.
Tue 3/34:14 pm
PHL
-
STL
1 stop7h 13m
Frontier
Sat 3/78:12 pm
STL
-
PHL
2 stops33h 55m
Frontier
Deal found 1/27$169
This Kiwi.com deal was found by Cheapflights users on 1/27. 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.
Fri 2/67:04 pm
PHL
-
STL
1 stop12h 47m
Frontier
Tue 2/103:49 pm
STL
-
PHL
1 stop19h 33m
Frontier
Deal found 1/27$173
This Expedia deal was found by Cheapflights users on 1/27. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/2112:33 pm
PHL
-
STL
1 stop12h 26m
Frontier
Mon 2/233:49 pm
STL
-
PHL
1 stop19h 50m
Frontier
Deal found 1/27$175
This Trip.com deal was found by Cheapflights users on 1/27. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/135:05 am
PHL
-
STL
1 stop9h 29m
Frontier
Fri 3/2012:16 pm
STL
-
PHL
1 stop11h 36m
Frontier
Deal found 1/27$177
This Kiwi.com deal was found by Cheapflights users on 1/27. 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.
Tue 2/106:40 pm
PHL
-
STL
1 stop13h 11m
Multiple Airlines
Fri 2/138:20 pm
STL
-
PHL
2 stops26h 30m
Multiple Airlines
Deal found 1/27$180
This Frontier deal was found by Cheapflights users on 1/26. 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.
Thu 2/511:09 am
PHL
-
STL
1 stop13h 24m
Frontier
Mon 2/910:16 am
STL
-
PHL
1 stop11h 16m
Frontier
Deal found 1/26$181

Find flight deals from Philadelphia to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Philadelphia (PHL) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated January 29, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$138
(Expedia)

One-way from

$64
(Frontier)

Popular in

May

Cheapest in

August

Average price

$397

Good round-trip deal

$401 or less

Good one-way deal

$221 or less
Provider with most accurate pricing for Philadelphia-Lambert-St Louis flight deals.
Provider most trusted by Cheapflights users for Philadelphia-Lambert-St Louis flights.
From Philadelphia to Lambert-St Louis
One-way flight from Philadelphia to Lambert-St Louis
Highest demand for flights based on searches. 7% potential increase in price ($34 potential increase over avg. RT price).
Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
Average for round-trip flights in January 2026
Price to beat on a round-trip flight from Philadelphia to Lambert-St Louis.
Price to beat on a one-way flight from Philadelphia to Lambert-St Louis.

Cheapflights Fare Finder

 
Customize your flight search to find flights from Philadelphia 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 January 29, 2026.
Use the filters below to find and compare flights from Philadelphia to St. Louis that are best for you.

Fly from

Philadelphia

Fly to

St. Louis

Route

Depart

Return

Price

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Sun 2/8

7:06 pm-6:51 am

1 stop12h 45m

Lambert-St Louis

Tue 2/10

3:49 pm-12:22 pm

1 stop19h 33m

$175

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Sat 3/7

10:38 pm-5:57 am

1 stop8h 19m

Lambert-St Louis

Mon 3/9

8:12 pm-5:31 am

1 stop8h 19m

$198

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Thu 2/26

3:15 pm-11:59 pm

1 stop9h 44m

Lambert-St Louis

Thu 3/5

3:49 pm-7:32 am

1 stop14h 43m

$210

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Thu 2/19

7:12 pm-6:51 am

1 stop12h 39m

Lambert-St Louis

Sun 2/22

3:49 pm-9:45 pm

2 stops28h 56m

$244

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Sat 3/7

10:38 pm-5:57 am

1 stop8h 19m

Lambert-St Louis

Mon 3/9

2:09 pm-8:44 am

2 stops17h 35m

$257

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Mon 2/23

5:05 pm-6:40 pm

Nonstop2h 35m

Lambert-St Louis

Wed 2/25

8:20 am-11:30 am

Nonstop2h 10m

$338

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Mon 2/23

5:05 pm-6:40 pm

Nonstop2h 35m

Lambert-St Louis

Tue 2/24

8:20 am-11:30 am

Nonstop2h 10m

$338

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Wed 4/29

10:33 am-9:08 pm

2 stops11h 35m

Lambert-St Louis

Tue 5/5

7:45 am-9:33 pm

1 stop12h 48m

$348

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Mon 2/23

5:00 pm-10:59 pm

1 stop6h 59m

Lambert-St Louis

Wed 2/25

9:55 am-5:14 pm

1 stop6h 19m

$352

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Tue 2/24

11:40 am-6:51 am

1 stop20h 11m

$68

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/27

Showing 1-10 of 17 results
1
2

Compare providers for flights from Philadelphia to St. Louis

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Philadelphia to St. Louis in January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy1 starTrust Score*3 stars
JustAirTicketPrice Accuracy-Trust Score*1 star

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Philadelphia-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Philadelphia-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Philadelphia-St. Louis flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Philadelphia-St. Louis flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Philadelphia-St. Louis flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Philadelphia to St. Louis

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

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

Use this chart to determine the optimal time to book a round-trip flight from Philadelphia to St. Louis. Price data was last updated on January 23, 2026.

Booking 87 days in advance of your planned departure date is, on average, the best time to get cheap flights from Philadelphia to St. Louis. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, March is the cheapest month in which you can book a flight from Philadelphia to St. Louis (average of $59). Flying from Philadelphia to St. Louis in December is currently the most expensive (average of $217). 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 PHL to STL?

Find hourly flight availability from Philadelphia 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 January 29, 2026.

It’s optimal to fly from Philadelphia to St. Louis in the afternoon. By choosing this option you can save up to 13% on the cost of your flight, compared to a flight at noon.

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

Use this chart to determine the cheapest time to fly round-trip from Philadelphia to St. Louis. Price data was last updated on January 24, 2026.

Travelers seeking maximum savings on their Philadelphia to St. Louis flight should consider departing on Saturday afternoons 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 Philadelphia to St. Louis?

The best insider tips for Philadelphia to St. Louis flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Philadelphia to St. Louis trip
Our travel experts
Mark Chesnut

Mark Chesnut

Expert on PHL

Mark Chesnut is a travel writer and public speaker with more than 30 years of experience. The 2019 winner of the NLGJA Excellence in Travel Writing Award, Mark is the author of the book “Prepare for Departure” and has covered air travel for multiple top consumer and trade media outlets.

Taryn White

Taryn White

Expert on STL

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. 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 St. Louis. Reviews last updated January 29, 2026.
See what other customers who have flown with Southwest, Delta, and American Airlines from Philadelphia to St. Louis have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

Comfort

8.0

Crew

8.6

Boarding

8.1

Food

7.0

Entertainment

7.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Comfort

8.0

Crew

8.6

Boarding

8.1

Food

7.0

Entertainment

7.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Comfort

8.0

Crew

8.6

Boarding

8.1

Food

7.0

Entertainment

7.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Comfort

8.0

Crew

8.6

Boarding

8.1

Food

7.0

Entertainment

7.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Comfort

8.0

Crew

8.6

Boarding

8.1

Food

7.0

Entertainment

7.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Comfort

8.0

Crew

8.6

Boarding

8.1

Food

7.0

Entertainment

7.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Related info for your journey

Find useful and relevant information for your journey from Philadelphia 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 airports do I use to fly from Philadelphia to St. Louis?

    Lambert-St Louis is the airport most travelers will use when flying to St. Louis from Philadelphia. Booking flights from Philadelphia (PHL) to Lambert-St Louis (STL) should be relatively easy as there are 4 daily flights to St. Louis from 5 different airlines. 2h 20m is how long a flight from Philadelphia to Lambert-St Louis will take if you book a nonstop flight.

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

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

    Airlines like Frontier fly from Philadelphia to St. Louis in about 12h 45m. The time it takes to get you to your destination can typically vary by up to . The distance between Philadelphia and St. Louis is about 811 mi.

  • What are the cheapest airlines flying from Philadelphia to St. Louis round-trip?

    Cheapflights users have booked flights from Philadelphia to St. Louis round-trip from $95. Other airlines that can offer you cheap pricing are Frontier, from $127, and American Airlines, from $241. These flights start at 76% lower than the current average price 3 months from now.

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

    The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $70. However, be on the lookout for offers from Spirit Airlines and American Airlines, as they are both options that can get you from Philadelphia to St. Louis for a low price.

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

    Consider Republic Airways (85%), American Airlines (82%) or PSA Airlines (82%) when booking your flight. These represent the most reliable airlines when flying from Philadelphia to St. Louis.

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

    Looking for the cheapest flight from Philadelphia to St. Louis? While on average our users pay $357, our data indicates the cheapest price to be $122. The most popular route (Philadelphia - Lambert-St Louis), is priced around $156.

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

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

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

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

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

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

    Currently, March is the cheapest month in which you can book a flight from Philadelphia to St. Louis (average of $59). Flying from Philadelphia to St. Louis in December is currently the most expensive (average of $217). 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
Swansea
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
Chesterfield
Alton
Farmington
Festus

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Philadelphia to St. Louis

See prices for flight routes from nearby airports that may be better suited for you.

Top 5 airlines flying from Philadelphia to St. Louis

Discover the top 5 airlines that operate flights from Philadelphia 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 January 29, 2026.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$95Average$178FlexibilityNo cancel feeOn-time65%
FrontierCheapest$127Average$212FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$241Average$417FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$253Average$421FlexibilityNo cancel feeOn-time63%
DeltaCheapest$259Average$358FlexibilityNo cancel feeOn-timeN/A

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