St. Louis

$89+ 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 5/5. Fares are subject to change and may not be available on all flights or dates of travel.
PHL — STL
May 6 — May 131
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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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Cheapflights Tip: The best prices from Philadelphia to Lambert-St Louis are usually found in July or August, booked 86 days in advance, depart on a Saturday or Wednesday and return on a Friday

Cheap 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 May 1, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$288
(Cheapflightsfares)

One-way from

$89
(Frontier)

Popular in

April

Cheapest in

July

Average price

$347

Good round-trip deal

$357 or less

Good one-way deal

$188 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. 15% potential increase in price ($64 potential increase over avg. RT price).
Cheapest flight prices on average. 2% potential price decrease ($10 potential savings vs. average RT price).
Average for round-trip flights in May 2025
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.

Find 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 May 1, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 4/30. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/126:10 amPHL - STL
1 stop13h 22mSpirit Airlines
Fri 8/158:44 amSTL - PHL
1 stop7h 26mSpirit Airlines
Deal found 4/30$288
This Booking.com deal was found by Cheapflights users on 4/30. 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.
Thu 5/110:59 pmPHL - STL
1 stop26h 15mFrontier
Sat 5/35:45 pmSTL - PHL
1 stop16h 52mFrontier
Deal found 4/30$300
This American Airlines deal was found by Cheapflights users on 4/30. 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.
Wed 5/217:14 pmPHL - STL
Nonstop2h 44mAmerican Airlines
Sat 5/246:20 amSTL - PHL
Nonstop2h 11mAmerican Airlines
Deal found 4/30$301
This Mytrip deal was found by Cheapflights users on 4/30. 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.
Wed 6/47:00 amPHL - STL
1 stop27h 15mMultiple Airlines
Fri 6/69:50 amSTL - PHL
3 stops34h 44mMultiple Airlines
Deal found 4/30$312
This Delta deal was found by Cheapflights users on 4/30. 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 8/128:25 amPHL - STL
1 stop4h 59mDelta
Tue 8/195:45 pmSTL - PHL
1 stop4h 16mDelta
Deal found 4/30$321
This Southwest deal was found by Cheapflights users on 4/30. 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 5/215:50 amPHL - STL
1 stop4h 20mSouthwest
Sat 5/245:45 amSTL - PHL
2 stops9h 00mSouthwest
Deal found 4/30$345
This United Airlines deal was found by Cheapflights users on 4/30. 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 6/410:35 amPHL - STL
2 stops11h 50mUnited Airlines
Wed 6/116:30 amSTL - PHL
1 stop6h 54mUnited Airlines
Deal found 4/30$396

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 May 1, 2025.
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

Wed 5/21

7:14 pm-8:58 pm

Nonstop2h 44m

Lambert-St Louis

Sat 5/24

6:20 am-9:31 am

Nonstop2h 11m

$301

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Thu 7/17

5:30 am-1:34 pm

1 stop9h 04m

Lambert-St Louis

Sun 7/20

2:36 pm-12:35 am

1 stop8h 59m

$302

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Sun 7/6

7:05 am-5:04 pm

1 stop10h 59m

Lambert-St Louis

Sun 7/27

8:44 am-5:10 pm

1 stop7h 26m

$303

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Wed 6/4

7:00 am-9:15 am

1 stop27h 15m

Lambert-St Louis

Fri 6/6

9:50 am-9:34 pm

3 stops34h 44m

$312

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Wed 5/21

6:00 am-9:35 am

1 stop4h 35m

Lambert-St Louis

Wed 5/21

3:40 pm-10:55 pm

1 stop6h 15m

$321

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Wed 5/21

5:50 am-9:10 am

1 stop4h 20m

Lambert-St Louis

Sat 5/24

5:45 am-3:45 pm

2 stops9h 00m

$345

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Wed 6/4

10:35 am-9:25 pm

2 stops11h 50m

Lambert-St Louis

Wed 6/11

6:30 am-2:24 pm

1 stop6h 54m

$396

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Mon 5/5

4:33 pm-12:06 am

1 stop8h 33m

$89

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Sun 6/22

7:05 am-5:04 pm

1 stop10h 59m

$122

PhiladelphiaSt. Louis

PHL - STL

PHLSTL

Philadelphia

Sun 6/1

4:00 pm-6:41 pm

2 stops27h 41m

$126

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/30

Showing 1-10 of 14 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 May.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*2 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy2 starsTrust Score*3 stars
GotogatePrice Accuracy3 starsTrust Score*2 stars
CheapfaremartPrice 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 eDreams the most. eDreams 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.

The best insider tips for Philadelphia to St. Louis flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your Philadelphia to St. Louis trip
Airlines
Southwest

Southwest offers free snacks and non-alcoholic beverages, enhancing the flight experience.


Enjoy free messaging and in-flight entertainment streamed to your device.

Frontier

Frontier offers extra comfort seats for a fee, ideal for flights around 3 hours.


Book early morning flights to avoid carry-over delays and ensure timely arrival.

Read more about Frontierby Marisa Garcia
Airports
PHL

For a quick departure, use the inter-terminal shuttle bus linking Terminals F, C, and A every 10 minutes.

Read more about PHLby Mark Chesnut
STL

Use the MetroLink light rail for a convenient, economical 40-minute ride from STL to downtown St. Louis.

Read more about STLby Taryn White
Our travel experts
Marisa Garcia

Marisa Garcia

Expert on Southwest and Frontier

Marisa Garcia

Marisa Garcia

Marisa knows planes inside and out, spending 16 years working on aircraft in hangars at airports around the world. She is an aviation industry expert, specialized in airline interiors and regulations. Ten years ago, she pivoted to journalism. She shares her insights in leading aviation, travel, and business publications and on her site FlightChic.

Read more
Mark Chesnut

Mark Chesnut

Expert on PHL

Mark Chesnut

Mark Chesnut

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.

Read more
Taryn White

Taryn White

Expert on STL

Taryn White

Taryn White

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.

Read more

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 April 25, 2025.

Booking 86 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, August is the cheapest month in which you can book a flight from Philadelphia to St. Louis (average of $311). Flying from Philadelphia 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 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 May 1, 2025.

It’s optimal to fly from Philadelphia to St. Louis at noon. By choosing this option you can save up to 23% on the cost of your flight, compared to a flight in the morning.

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 March 30, 2025.

Travelers seeking maximum savings on their Philadelphia to St. Louis flight should consider departing on Wednesday evenings 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.

Weekly flight availability from Philadelphia to St. Louis

Explore weekly flight availability from Philadelphia 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 May 1, 2025.

The most flights from PHL to STL are scheduled on a Monday (8 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (1 on average).

Rainfall in St. Louis by month

Plan your trip to St. Louis by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in St. Louis ranges from 2.2 - 4.7 inches per month. May is typically the wettest month, when rainfall can reach 4.7 in. February is typically the driest time to visit St. Louis when rainfall is around 2.2 in.

Temperature in St. Louis by month

Plan your trip to St. Louis by taking into account the average temperature totals by month.

If weather is an important factor for your trip to St. Louis, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 32.0 F).

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 May 1, 2025.
To help decide which airline to fly from Philadelphia to St. Louis, see what other customers have to say about Alaska Airlines, Southwest and Delta. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Boarding

8.2

Overall

8.0

Entertainment

7.1

Crew

8.5

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Boarding

8.2

Overall

8.0

Entertainment

7.1

Crew

8.5

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Boarding

8.2

Overall

8.0

Entertainment

7.1

Crew

8.5

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
8.0
Very good

Boarding

8.2

Overall

8.0

Entertainment

7.1

Crew

8.5

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Boarding

8.2

Overall

8.0

Entertainment

7.1

Crew

8.5

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Boarding

8.2

Overall

8.0

Entertainment

7.1

Crew

8.5

Comfort

7.9

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

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 5 daily flights to St. Louis from 4 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?

  • 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 $288. Other airlines that can offer you cheap pricing are American Airlines, from $301, and Frontier, from $302. These flights start at 16% 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 $89. 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 Southwest (82%), Aer Lingus (70%) or PSA Airlines (66%) 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 $324, our data indicates the cheapest price to be $136. The most popular route (Philadelphia - Lambert-St Louis), is priced around $211.

  • 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, August is the cheapest month in which you can book a flight from Philadelphia to St. Louis (average of $311). Flying from Philadelphia 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 Philadelphia?

Book flights to Philadelphia if you plan to visit one of these locations
Fenton
Maryland Heights
Fairview Heights
Collinsville
Wentzville
Eureka
St. Peters
Festus
Glencoe
Alton
Farmington
O'Fallon

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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 4 airlines flying from Philadelphia to St. Louis

Discover the top 4 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 May 1, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$53Average$90FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$131Average$303FlexibilityNo cancel feeOn-time71%
DeltaCheapest$199Average$318FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$274Average$417FlexibilityNo cancel feeOn-time63%

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