$70+ 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 5/14. Fares are subject to change and may not be available on all flights or dates of travel.
STL — PHL
May 21 — May 281
Round-trip
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 Friday or Thursday and return on a Wednesday
Cheap flight deals from St. Louis to Philadelphia
Cheapest
Best
Last-minute
One-way
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 April 21, 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 April 21, 2026.
This Priceline deal was found by Cheapflights users on 4/20. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/144:19 pm
STL
- PHL
1 stop7h 21m
Frontier
Sun 5/176:10 am
PHL
- STL
1 stop9h 38m
Frontier
Deal found 4/20![Frontier logo]()
$140
This Frontier deal was found by Cheapflights users on 4/17. 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 5/98:08 pm
STL
- PHL
1 stop8h 29m
Frontier
Mon 5/1110:11 am
PHL
- STL
1 stop15h 10m
Frontier
Deal found 4/17![Frontier logo]()
$141
This Expedia deal was found by Cheapflights users on 4/17. 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.
Thu 5/76:55 pm
STL
- PHL
1 stop11h 17m
Frontier
Sat 5/98:35 pm
PHL
- STL
1 stop23h 48m
Frontier
Deal found 4/17![Frontier logo]()
$160
This Frontier deal was found by Cheapflights users on 4/17. 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 5/218:08 pm
STL
- PHL
1 stop8h 29m
Frontier
Tue 5/268:30 am
PHL
- STL
1 stop10h 03m
Frontier
Deal found 4/17![Frontier logo]()
$165
This Kiwi.com deal was found by Cheapflights users on 4/18. 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.
Sat 5/98:08 pm
STL
- PHL
1 stop8h 29m
Multiple Airlines
Mon 5/118:44 pm
PHL
- STL
2 stops21h 49m
Multiple Airlines
Deal found 4/18![Multiple Airlines logo]()
$170
This Frontier deal was found by Cheapflights users on 4/17. 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 5/284:19 pm
STL
- PHL
1 stop7h 21m
Frontier
Sun 5/316:10 am
PHL
- STL
1 stop9h 21m
Frontier
Deal found 4/17![Frontier logo]()
$180
This Expedia deal was found by Cheapflights users on 4/19. 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 5/114:19 pm
STL
- PHL
1 stop15h 40m
Frontier
Thu 5/149:05 pm
PHL
- STL
1 stop28h 16m
Frontier
Deal found 4/19![Frontier logo]()
$181
This Orbitz deal was found by Cheapflights users on 4/17. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/144:19 pm
STL
- PHL
1 stop7h 21m
Frontier
Mon 5/187:55 am
PHL
- STL
1 stop17h 26m
Frontier
Deal found 4/17![Frontier logo]()
$186
This Booking.com deal was found by Cheapflights users on 4/20. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/58:08 pm
STL
- PHL
1 stop8h 29m
Frontier
Mon 6/810:40 am
PHL
- STL
1 stop31h 25m
Frontier
Deal found 4/20![Frontier logo]()
$187
This Frontier deal was found by Cheapflights users on 4/20. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/76:33 pm
STL
- PHL
1 stop11h 46m
Frontier
Tue 7/146:30 am
PHL
- STL
1 stop12h 00m
Frontier
Deal found 4/20![Frontier logo]()
$190
This CheapOair deal was found by Cheapflights users on 4/21. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/84:19 pm
STL
- PHL
1 stop6h 10m
Frontier
Sun 5/106:10 am
PHL
- STL
1 stop9h 38m
Frontier
Deal found 4/21![Frontier logo]()
$191
Best flights from St. Louis to PhiladelphiaDiscover carefully curated flight deals from St. Louis to Philadelphia that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 21, 2026.
Discover carefully curated flight deals from St. Louis to Philadelphia that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 21, 2026.
This Southwest deal was found by Cheapflights users on 4/18. 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.
Sat 5/96:55 pm
STL
- PHL
Nonstop2h 10m
Southwest
Mon 5/117:10 pm
PHL
- STL
Nonstop2h 40m
Southwest
Deal found 4/18![Southwest logo]()
$400
This United Airlines deal was found by Cheapflights users on 4/17. 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.
Sun 6/146:00 am
STL
- PHL
1 stop5h 25m
United Airlines
Sun 6/148:26 pm
PHL
- STL
1 stop4h 53m
United Airlines
Deal found 4/17![United Airlines logo]()
$483
This Southwest deal was found by Cheapflights users on 4/20. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/26:55 pm
STL
- PHL
Nonstop2h 10m
Southwest
Sun 5/37:30 pm
PHL
- STL
Nonstop2h 40m
Southwest
Deal found 4/20![Southwest logo]()
$461
This Southwest deal was found by Cheapflights users on 4/18. 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.
Sat 5/166:10 am
STL
- PHL
2 stops8h 35m
Southwest
Sat 5/239:45 am
PHL
- STL
2 stops9h 25m
Southwest
Deal found 4/18![Southwest logo]()
$466
This Southwest deal was found by Cheapflights users on 4/19. 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.
Tue 6/26:50 pm
STL
- PHL
Nonstop2h 10m
Southwest
Sat 6/61:45 pm
PHL
- STL
Nonstop2h 20m
Southwest
Deal found 4/19![Southwest logo]()
$471
This Southwest deal was found by Cheapflights users on 4/20. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/131:00 pm
STL
- PHL
Nonstop2h 10m
Southwest
Wed 6/176:20 am
PHL
- STL
Nonstop2h 20m
Southwest
Deal found 4/20![Southwest logo]()
$471
This Southwest deal was found by Cheapflights users on 4/19. 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.
Fri 7/317:55 pm
STL
- PHL
Nonstop2h 10m
Southwest
Sun 8/26:20 am
PHL
- STL
Nonstop2h 20m
Southwest
Deal found 4/19![Southwest logo]()
$479
This Southwest deal was found by Cheapflights users on 4/16. 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.
Fri 6/197:55 pm
STL
- PHL
Nonstop2h 10m
Southwest
Sun 6/216:20 am
PHL
- STL
Nonstop2h 20m
Southwest
Deal found 4/16![Southwest logo]()
$479
This Southwest deal was found by Cheapflights users on 4/18. 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.
Thu 5/78:25 am
STL
- PHL
2 stops7h 50m
Southwest
Sat 5/99:45 am
PHL
- STL
2 stops9h 00m
Southwest
Deal found 4/18![Southwest logo]()
$486
This Southwest deal was found by Cheapflights users on 4/17. 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.
Fri 7/107:55 pm
STL
- PHL
Nonstop2h 10m
Southwest
Mon 7/134:45 pm
PHL
- STL
1 stop6h 55m
Southwest
Deal found 4/17![Southwest logo]()
$489
This Southwest deal was found by Cheapflights users on 4/16. 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.
Thu 7/27:55 pm
STL
- PHL
Nonstop2h 10m
Southwest
Sun 7/56:20 am
PHL
- STL
Nonstop2h 20m
Southwest
Deal found 4/16![Southwest logo]()
$490
Last-minute flights from St. Louis to PhiladelphiaDiscover last-minute flight deals from St. Louis to Philadelphia. Data last updated April 21, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Philadelphia. Data last updated April 21, 2026 and is based on user searches.
This Expedia deal was found by Cheapflights users on 4/17. 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.
Thu 5/76:55 pm
STL
- PHL
1 stop11h 17m
Frontier
Sat 5/98:35 pm
PHL
- STL
1 stop23h 48m
Frontier
Deal found 4/17![Frontier logo]()
$160
This CheapOair deal was found by Cheapflights users on 4/21. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/84:19 pm
STL
- PHL
1 stop6h 10m
Frontier
Sun 5/106:10 am
PHL
- STL
1 stop9h 38m
Frontier
Deal found 4/21![Frontier logo]()
$191
This Frontier deal was found by Cheapflights users on 4/17. 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 5/98:08 pm
STL
- PHL
1 stop8h 29m
Frontier
Mon 5/1110:11 am
PHL
- STL
1 stop15h 10m
Frontier
Deal found 4/17![Frontier logo]()
$141
This Kiwi.com deal was found by Cheapflights users on 4/18. 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.
Sat 5/98:08 pm
STL
- PHL
1 stop8h 29m
Multiple Airlines
Mon 5/118:44 pm
PHL
- STL
2 stops21h 49m
Multiple Airlines
Deal found 4/18![Multiple Airlines logo]()
$170
This Expedia deal was found by Cheapflights users on 4/19. 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 5/114:19 pm
STL
- PHL
1 stop15h 40m
Frontier
Thu 5/149:05 pm
PHL
- STL
1 stop28h 16m
Frontier
Deal found 4/19![Frontier logo]()
$181
This Priceline deal was found by Cheapflights users on 4/20. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/144:19 pm
STL
- PHL
1 stop7h 21m
Frontier
Sun 5/176:10 am
PHL
- STL
1 stop9h 38m
Frontier
Deal found 4/20![Frontier logo]()
$140
This Orbitz deal was found by Cheapflights users on 4/17. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/144:19 pm
STL
- PHL
1 stop7h 21m
Frontier
Mon 5/187:55 am
PHL
- STL
1 stop17h 26m
Frontier
Deal found 4/17![Frontier logo]()
$186
This Frontier deal was found by Cheapflights users on 4/17. 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 5/218:08 pm
STL
- PHL
1 stop8h 29m
Frontier
Tue 5/268:30 am
PHL
- STL
1 stop10h 03m
Frontier
Deal found 4/17![Frontier logo]()
$165
This Frontier deal was found by Cheapflights users on 4/17. 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 5/284:19 pm
STL
- PHL
1 stop7h 21m
Frontier
Sun 5/316:10 am
PHL
- STL
1 stop9h 21m
Frontier
Deal found 4/17![Frontier logo]()
$180
This Expedia deal was found by Cheapflights users on 4/17. 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 5/304:19 pm
STL
- PHL
1 stop15h 35m
Frontier
Sun 5/319:16 pm
PHL
- STL
1 stop14h 13m
Frontier
Deal found 4/17![Frontier logo]()
$201
One-way flights from St. Louis to PhiladelphiaSearch for one-way flight options from St. Louis to Philadelphia. Find affordable one-way fares based on user searches. Data last updated April 21, 2026.
Search for one-way flight options from St. Louis to Philadelphia. Find affordable one-way fares based on user searches. Data last updated April 21, 2026.
This Frontier deal was found by Cheapflights users on 4/16. 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 5/144:19 pm
STL
- PHL
1 stop7h 21m
Frontier
Deal found 4/16![Frontier logo]()
$70
This Frontier deal was found by Cheapflights users on 4/19. 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.
Fri 5/158:08 pm
STL
- PHL
1 stop8h 29m
Frontier
Deal found 4/19![Frontier logo]()
$90
This Frontier deal was found by Cheapflights users on 4/17. 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.
Wed 6/177:46 pm
STL
- PHL
1 stop9h 41m
Frontier
Deal found 4/17![Frontier logo]()
$95
This Expedia deal was found by Cheapflights users on 4/18. 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.
Sun 6/74:19 pm
STL
- PHL
1 stop15h 35m
Frontier
Deal found 4/18![Frontier logo]()
$96
This Kiwi.com deal was found by Cheapflights users on 4/16. 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 5/196:33 pm
STL
- PHL
2 stops27h 59m
Multiple Airlines
Deal found 4/16![Multiple Airlines logo]()
$97
This Kiwi.com deal was found by Cheapflights users on 4/16. 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 5/135:27 pm
STL
- PHL
2 stops30h 17m
Frontier
Deal found 4/16![Frontier logo]()
$98
This Expedia deal was found by Cheapflights users on 4/17. 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 6/166:31 pm
STL
- PHL
1 stop11h 48m
Frontier
Deal found 4/17![Frontier logo]()
$101
This Kiwi.com deal was found by Cheapflights users on 4/16. 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.
Mon 5/185:27 pm
STL
- PHL
2 stops29h 21m
Frontier
Deal found 4/16![Frontier logo]()
$103
This Kiwi.com deal was found by Cheapflights users on 4/16. 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 5/76:55 pm
STL
- PHL
2 stops28h 03m
Multiple Airlines
Deal found 4/16![Multiple Airlines logo]()
$108
This Frontier deal was found by Cheapflights users on 4/17. 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 6/184:17 pm
STL
- PHL
1 stop7h 27m
Frontier
Deal found 4/17![Frontier logo]()
$115
Find 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 April 21, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $140 (Expedia) |
One-way from | $70 (Frontier) |
Popular in | November |
Cheapest in | August |
Average price | $407 |
Good round-trip deal | $429 or less |
Good one-way deal | $217 or less |
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 April 21, 2026.
Use the filters below to find and compare flights from St. Louis to Philadelphia that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Sat 5/9
6:55 pm-10:05 pm
Nonstop2h 10m
Philadelphia
Mon 5/11
7:10 pm-8:50 pm
Nonstop2h 40m
$400
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Sat 5/2
6:55 pm-10:05 pm
Nonstop2h 10m
Philadelphia
Sun 5/3
7:30 pm-9:10 pm
Nonstop2h 40m
$461
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Sat 5/16
6:10 am-3:45 pm
2 stops8h 35m
Philadelphia
Sat 5/23
9:45 am-6:10 pm
2 stops9h 25m
$466
Quickest round-trip
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Tue 6/2
6:50 pm-10:00 pm
Nonstop2h 10m
Philadelphia
Sat 6/6
1:45 pm-3:05 pm
Nonstop2h 20m
$471
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Sat 6/13
1:00 pm-4:10 pm
Nonstop2h 10m
Philadelphia
Wed 6/17
6:20 am-7:40 am
Nonstop2h 20m
$471
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Fri 7/31
7:55 pm-11:05 pm
Nonstop2h 10m
Philadelphia
Sun 8/2
6:20 am-7:40 am
Nonstop2h 20m
$479
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Fri 6/19
7:55 pm-11:05 pm
Nonstop2h 10m
Philadelphia
Sun 6/21
6:20 am-7:40 am
Nonstop2h 20m
$479
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Sun 6/14
6:00 am-12:25 pm
1 stop5h 25m
Philadelphia
Sun 6/14
8:26 pm-12:19 am
1 stop4h 53m
$483
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Thu 5/7
8:25 am-5:15 pm
2 stops7h 50m
Philadelphia
Sat 5/9
9:45 am-5:45 pm
2 stops9h 00m
$486
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Fri 7/10
7:55 pm-11:05 pm
Nonstop2h 10m
Philadelphia
Mon 7/13
4:45 pm-10:40 pm
1 stop6h 55m
$489
Showing 1-10 of 23 resultsSorted by cheapest first
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 April.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy2 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 FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Philadelphia flight deals on Cheapflights vs. FlightHub >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 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 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.
STL-PHL
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
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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 April 17, 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 $277). Flying from St. Louis to Philadelphia in November is currently the most expensive (average of $493). 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 April 21, 2026.
It’s typically best to fly out from St. Louis to Philadelphia in the evening. Doing so could potentially save you 60% 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 April 18, 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. Saturday 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 63% 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.
Atlanta (ATL) is the most affordable 1-stop option, with an average round-trip price of $154.
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
Our travel experts
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 April 21, 2026.
Read reviews from past customers who have flown Southwest,United Airlines, andAmerican 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.
Boarding
8.1
Comfort
8.0
Crew
8.6
Food
7.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Boarding
8.1
Comfort
8.0
Crew
8.6
Food
7.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Boarding
8.1
Comfort
8.0
Crew
8.6
Food
7.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Boarding
8.1
Comfort
8.0
Crew
8.6
Food
7.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Boarding
8.1
Comfort
8.0
Crew
8.6
Food
7.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Boarding
8.1
Comfort
8.0
Crew
8.6
Food
7.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
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
King of Prussia
Reading
Camden
Ocean City
Lewes
Dewey Beach
Pottstown
Ephrata
Vineland
Milford
Dover
Elkton
Essington
Willow Grove
New Castle
Millville
Glen Mills
Chester
Newark
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St. Louis and Philadelphia flights
Browse other St. Louis and Philadelphia flight options. Last updated on April 21, 2026.
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Browse through other flights departing from St. Louis. Flights are based on user searches made on Cheapflights and were last updated on April 21, 2026.
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Top 6 airlines flying from St. Louis to Philadelphia
Discover the top 6 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 April 21, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$82 | Average$219 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$141 | Average$236 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$204 | Average$734 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$231 | Average$428 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$240 | Average$425 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$252 | Average$443 | FlexibilityNo cancel fee | On-time63% |