Expect security screening at STL to take 5-10 minutes during off-peak times. Check real-time wait times online before heading to the airport.
$68+ Cheap flights from St. Louis to Philadelphia (STL - PHL)
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 2/3. Fares are subject to change and may not be available on all flights or dates of travel.
STL — PHL
Feb 7 — Feb 141
1 adult, Economy
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Find cheap flights from St. Louis to Philadelphia with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheapflights Tip: The best prices from Lambert-St Louis to Philadelphia are usually found in August or September, booked 76 days in advance, depart on a Thursday or Friday and return on a Wednesday
Cheap flight deals from St. Louis to Philadelphia
Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Philadelphia (PHL). 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 8, 2026.
Most accurate provider | eDreams 3 stars |
|---|---|
Most trusted provider | eDreams 3 stars |
Round-trip from | $128 (Expedia) |
One-way from | $68 (Kiwi.com) |
Popular in | November |
Cheapest in | August |
Average price | $426 |
Good round-trip deal | $509 or less |
Good one-way deal | $260 or less |
Find flight deals from St. Louis to Philadelphia
Cheapest flights from St. Louis to PhiladelphiaExplore the most affordable flight options available from St. Louis to Philadelphia. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 8, 2026.
Explore the most affordable flight options available from St. Louis to Philadelphia. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 8, 2026.
This Expedia deal was found by Cheapflights users on 1/8. 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.
Wed 2/183:49 pmSTL - PHL
1 stop29h 04mFrontier
Tue 2/242:09 pmPHL - STL
1 stop9h 18mFrontier
Deal found 1/8![Frontier logo]()
$128
This Kiwi.com deal was found by Cheapflights users on 1/7. 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.
Wed 2/45:42 pmSTL - PHL
1 stop15h 17mMultiple Airlines
Wed 2/115:30 amPHL - STL
1 stop17h 57mMultiple Airlines
Deal found 1/7![Multiple Airlines logo]()
$137
This Priceline deal was found by Cheapflights users on 1/7. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 1/2412:12 pmSTL - PHL
1 stop9h 20mFrontier
Mon 1/263:54 pmPHL - STL
1 stop8h 39mFrontier
Deal found 1/7![Frontier logo]()
$144
This Travelocity deal was found by Cheapflights users on 1/7. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/114:51 pmSTL - PHL
1 stop13h 45mFrontier
Sat 3/141:44 pmPHL - STL
1 stop10h 35mFrontier
Deal found 1/7![Frontier logo]()
$150
This Kiwi.com deal was found by Cheapflights users on 1/8. 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 1/295:42 pmSTL - PHL
1 stop25h 15mFrontier
Tue 2/310:35 amPHL - STL
1 stop13h 58mFrontier
Deal found 1/8![Frontier logo]()
$152
This Booking.com deal was found by Cheapflights users on 1/7. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/253:49 pmSTL - PHL
1 stop18h 52mFrontier
Sat 2/286:13 pmPHL - STL
1 stop6h 46mFrontier
Deal found 1/7![Frontier logo]()
$154
This Kiwi.com deal was found by Cheapflights users on 1/7. 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.
Fri 2/278:22 pmSTL - PHL
1 stop13h 51mFrontier
Tue 3/34:14 pmPHL - STL
1 stop7h 13mFrontier
Deal found 1/7![Frontier logo]()
$155
This Kiwi.com deal was found by Cheapflights users on 1/7. 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.
Sun 1/255:42 pmSTL - PHL
1 stop14h 39mFrontier
Tue 1/2710:35 amPHL - STL
1 stop13h 58mFrontier
Deal found 1/7![Frontier logo]()
$156
This Kiwi.com deal was found by Cheapflights users on 1/7. 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.
Sun 1/255:42 pmSTL - PHL
1 stop27h 21mMultiple Airlines
Sun 2/110:45 pmPHL - STL
1 stop11h 36mMultiple Airlines
Deal found 1/7![Multiple Airlines logo]()
$157
This Kiwi.com deal was found by Cheapflights users on 1/7. 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.
Fri 2/68:22 pmSTL - PHL
1 stop13h 56mFrontier
Sun 2/87:06 pmPHL - STL
1 stop12h 45mFrontier
Deal found 1/7![Frontier logo]()
$158
This Frontier deal was found by Cheapflights users on 1/6. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/219:41 amSTL - PHL
1 stop11h 08mFrontier
Wed 2/2510:50 amPHL - STL
1 stop12h 37mFrontier
Deal found 1/6![Frontier logo]()
$159
Cheapflights Fare Finder
Customize your flight search to find flights from St. Louis to Philadelphia 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 8, 2026.
Use the filters below to find and compare flights from St. Louis to Philadelphia that are best for you.
Fly from
St. Louis
Fly to
Philadelphia
Route
Depart
Return
Price
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Fri 2/27
8:22 pm-11:13 am
1 stop13h 51m
Philadelphia
Tue 3/3
4:14 pm-10:27 pm
1 stop7h 13m
$155
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Sun 1/25
5:42 pm-9:21 am
1 stop14h 39m
Philadelphia
Tue 1/27
10:35 am-11:33 pm
1 stop13h 58m
$156
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Sat 1/24
12:12 pm-10:32 pm
1 stop9h 20m
Philadelphia
Sun 1/25
8:25 pm-9:21 am
1 stop13h 56m
$167
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Sun 1/25
5:42 pm-10:03 pm
1 stop27h 21m
Philadelphia
Sun 2/1
6:30 am-6:51 am
2 stops25h 21m
$178
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Sun 2/22
3:49 pm-7:32 am
1 stop14h 43m
Philadelphia
Wed 2/25
10:50 am-10:27 pm
1 stop12h 37m
$229
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Wed 2/18
2:00 pm-5:17 pm
Nonstop2h 17m
Philadelphia
Tue 2/24
11:00 am-12:33 pm
Nonstop2h 33m
$255
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Wed 4/8
1:40 pm-4:50 pm
Nonstop2h 10m
Philadelphia
Wed 4/15
7:30 am-11:30 am
1 stop5h 00m
$265
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Wed 4/8
6:59 pm-12:57 am
1 stop4h 58m
Philadelphia
Wed 4/15
9:41 am-1:00 pm
1 stop4h 19m
$275
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Wed 4/8
6:00 am-2:21 pm
1 stop7h 21m
Philadelphia
Wed 4/15
7:15 am-11:19 am
1 stop5h 04m
$275
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Wed 4/1
3:30 pm-12:40 am
1 stop8h 10m
Philadelphia
Mon 4/6
10:00 pm-9:47 am
2 stops12h 47m
$292
Showing 1-10 of 20 results
Compare providers for flights from St. Louis to Philadelphia
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 St. Louis to Philadelphia in January.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*2 stars | |
| Price Accuracy1 star | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on St. Louis-Philadelphia flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on St. Louis-Philadelphia flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from St. Louis-Philadelphia flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on St. Louis-Philadelphia 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 St. Louis-Philadelphia 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 St. Louis to Philadelphia
Have a flexible travel schedule? Discover the best time to fly to Philadelphia from St. Louis 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 St. Louis to Philadelphia
Prices
Airlines
More
How far ahead should I book a flight from St. Louis to Philadelphia?
Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Philadelphia. Price data was last updated on January 2, 2026.
The price you pay for your flight from St. Louis to Philadelphia may vary depending on when you book. For the best chance of a lower fare, look to book 76 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
What is the cheapest month to book a flight from St. Louis to Philadelphia?
Currently, August is the cheapest month in which you can book a flight from St. Louis to Philadelphia (average of $129). Flying from St. Louis to Philadelphia in May is currently the most expensive (average of $199). 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 STL to PHL?
Find hourly flight availability from St. Louis to Philadelphia. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated January 8, 2026.
It’s typically best to fly out from St. Louis to Philadelphia in the evening. Doing so could potentially save you 64% on the flight price compared to flying at noon, which is usually more expensive.
What is the cheapest day to fly from St. Louis to Philadelphia?
Use this chart to determine the cheapest time to fly round-trip from St. Louis to Philadelphia. Price data was last updated on January 3, 2026.
Travelers seeking maximum savings on their St. Louis to Philadelphia flight should consider departing on Wednesday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
What’s the top layover airport for flights from St. Louis to Philadelphia?
Share of 1-stop round-trip flights from St. Louis to Philadelphia chosen by Cheapflights users in the past 12 months, using the same layover each way.
Detroit (DTW) – chosen by Cheapflights users on 71% of 1-stop itineraries from St. Louis to Philadelphia on Cheapflights.
What’s the cheapest layover airport for flights from St. Louis to Philadelphia?
Average round-trip fare for 1-stop flights from St. Louis to Philadelphia, chosen by Cheapflights users in the past 12 months, with the same layover each way.
Detroit (DTW) is the most affordable 1-stop option, with an average round-trip price of $196.
What’s the fastest layover option from St. Louis to Philadelphia?
Shortest average travel time for 1-stop one-way flights from St. Louis to Philadelphia, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.
Flights via Orlando (MCO) have the shortest average one-way travel time for 1-stop routes: 6h 14m.
Which airport typically offers the quickest layover for flights from St. Louis to Philadelphia?
Average layover duration for 1-stop one-way flights from St. Louis to Philadelphia, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.
Flights via Orlando (MCO) offer the fastest connection on this route, with an average layover time of 2h 19m.
The best insider tips for St. Louis to Philadelphia 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 St. Louis to Philadelphia trip
Reviews of airlines servicing Philadelphia
Get insights into the airlines that provide service to Philadelphia. 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 Philadelphia. Reviews last updated January 8, 2026.
Read reviews from past customers who have flown Southwest, American Airlines, and Spirit Airlines from St. Louis to Philadelphia. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Comfort
8.0
Entertainment
7.5
Food
7.0
Boarding
8.1
Crew
8.6
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Entertainment
7.5
Food
7.0
Boarding
8.1
Crew
8.6
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Entertainment
7.5
Food
7.0
Boarding
8.1
Crew
8.6
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Entertainment
7.5
Food
7.0
Boarding
8.1
Crew
8.6
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Entertainment
7.5
Food
7.0
Boarding
8.1
Crew
8.6
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Related info for your journey
Find useful and relevant information for your journey from St. Louis to Philadelphia. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Traveling to a place near Philadelphia?
Book flights to Philadelphia if you plan to visit one of these locationsWildwood
Pottstown
Reading
Ocean City
King of Prussia
Cherry Hill
Lewes
Dewey Beach
Ephrata
Camden
Vineland
Milford
Dover
Elkton
Essington
Willow Grove
New Castle
Millville
Newark
Chester
Browse thousands of different options on Cheapflights for your next trip
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Alternative routes for St. Louis to Philadelphia
See prices for flight routes from nearby airports that may be better suited for you.
Top 4 airlines flying from St. Louis to Philadelphia
Discover the top 4 airlines that operate flights from St. Louis to Philadelphia. 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 8, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$132 | Average$219 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$141 | Average$233 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$243 | Average$422 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$295 | Average$422 | FlexibilityNo cancel fee | On-time63% |