$77+ 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 5/9. Fares are subject to change and may not be available on all flights or dates of travel.
STL — PHL
Apr 9 — Apr 161
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 53 days in advance, depart on a Thursday or Friday and return on a Wednesday
Cheap flight deals from St. Louis to Philadelphia
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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 March 10, 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 March 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Tue 4/217:10 pm
PHL
- STL
1 stop12h 40m
Frontier
Deal found 3/6![Frontier logo]()
$149
This Priceline deal was found by Cheapflights users on 3/6. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/88:16 pm
STL
- PHL
1 stop8h 15m
Frontier
Sat 4/114:11 pm
PHL
- STL
1 stop8h 14m
Frontier
Deal found 3/6![Frontier logo]()
$160
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Wed 4/2211:02 am
PHL
- STL
1 stop24h 28m
Frontier
Deal found 3/6![Frontier logo]()
$161
This CheapOair deal was found by Cheapflights users on 3/9. 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.
Wed 4/88:16 pm
STL
- PHL
1 stop8h 15m
Frontier
Wed 4/158:41 pm
PHL
- STL
1 stop23h 40m
Frontier
Deal found 3/9![Frontier logo]()
$171
This Booking.com deal was found by Cheapflights users on 3/8. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/228:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Wed 4/297:56 pm
PHL
- STL
1 stop28h 23m
Frontier
Deal found 3/8![Frontier logo]()
$172
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/188:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Tue 4/217:10 pm
PHL
- STL
1 stop12h 40m
Frontier
Deal found 3/6![Frontier logo]()
$176
This Frontier deal was found by Cheapflights users on 3/9. 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 5/18:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Tue 5/511:48 am
PHL
- STL
1 stop12h 31m
Frontier
Deal found 3/9![Frontier logo]()
$180
This Frontier deal was found by Cheapflights users on 3/6. 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.
Thu 4/3011:21 am
STL
- PHL
1 stop6h 58m
Frontier
Sat 5/24:42 pm
PHL
- STL
1 stop7h 37m
Frontier
Deal found 3/6![Frontier logo]()
$181
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/38:16 pm
STL
- PHL
1 stop8h 15m
Frontier
Mon 4/67:11 pm
PHL
- STL
1 stop16h 19m
Frontier
Deal found 3/6![Frontier logo]()
$182
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/38:16 pm
STL
- PHL
1 stop8h 15m
Frontier
Wed 4/87:10 pm
PHL
- STL
1 stop23h 24m
Frontier
Deal found 3/6![Frontier logo]()
$183
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
- PHL
1 stop10h 47m
Multiple Airlines
Sun 4/197:00 am
PHL
- STL
1 stop24h 50m
Multiple Airlines
Deal found 3/6![Multiple Airlines logo]()
$188
This CheapOair deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/118:13 pm
STL
- PHL
1 stop10h 57m
Frontier
Wed 5/138:00 am
PHL
- STL
1 stop16h 19m
Frontier
Deal found 3/6![Frontier logo]()
$192
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 March 10, 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 March 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 3/9. 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 4/238:06 pm
STL
- PHL
1 stop8h 28m
Frontier
Thu 4/3010:38 pm
PHL
- STL
2 stops33h 12m
Frontier
Deal found 3/9![Frontier logo]()
$265
This Southwest deal was found by Cheapflights users on 3/9. 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 4/81:40 pm
STL
- PHL
Nonstop2h 10m
Southwest
Wed 4/156:35 pm
PHL
- STL
Nonstop2h 25m
Southwest
Deal found 3/9![Southwest logo]()
$277
This American Airlines deal was found by Cheapflights users on 3/9. 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.
Fri 6/55:40 pm
STL
- PHL
Nonstop2h 29m
American Airlines
Mon 6/89:01 am
PHL
- STL
Nonstop2h 36m
American Airlines
Deal found 3/9![American Airlines logo]()
$371
This Delta deal was found by Cheapflights users on 3/6. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/47:15 am
STL
- PHL
1 stop6h 45m
Delta
Sat 6/136:20 pm
PHL
- STL
1 stop6h 18m
Delta
Deal found 3/6![Delta logo]()
$391
This Southwest deal was found by Cheapflights users on 3/9. 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 4/156:50 pm
STL
- PHL
Nonstop2h 10m
Southwest
Mon 4/206:00 pm
PHL
- STL
1 stop5h 45m
Southwest
Deal found 3/9![Southwest logo]()
$298
This Southwest deal was found by Cheapflights users on 3/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/111:45 pm
STL
- PHL
1 stop7h 00m
Southwest
Mon 5/187:10 pm
PHL
- STL
Nonstop2h 40m
Southwest
Deal found 3/8![Southwest logo]()
$309
This Southwest deal was found by Cheapflights users on 3/9. 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 4/231:35 pm
STL
- PHL
Nonstop2h 10m
Southwest
Thu 4/306:00 pm
PHL
- STL
1 stop5h 45m
Southwest
Deal found 3/9![Southwest logo]()
$309
This Southwest deal was found by Cheapflights users on 3/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/222:30 pm
STL
- PHL
1 stop6h 30m
Southwest
Wed 4/296:35 pm
PHL
- STL
Nonstop2h 25m
Southwest
Deal found 3/8![Southwest logo]()
$309
This Southwest deal was found by Cheapflights users on 3/9. 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.
Mon 5/41:45 pm
STL
- PHL
2 stops8h 00m
Southwest
Fri 5/812:45 pm
PHL
- STL
2 stops7h 10m
Southwest
Deal found 3/9![Southwest logo]()
$365
This Southwest deal was found by Cheapflights users on 3/9. 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 5/77:35 am
STL
- PHL
2 stops7h 15m
Southwest
Mon 5/1111:10 am
PHL
- STL
2 stops8h 45m
Southwest
Deal found 3/9![Southwest logo]()
$365
This Southwest deal was found by Cheapflights users on 3/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/231:35 pm
STL
- PHL
Nonstop2h 10m
Southwest
Sun 4/265:50 am
PHL
- STL
1 stop4h 15m
Southwest
Deal found 3/8![Southwest logo]()
$381
Last-minute flights from St. Louis to PhiladelphiaDiscover last-minute flight deals from St. Louis to Philadelphia. Data last updated March 10, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Philadelphia. Data last updated March 10, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/38:16 pm
STL
- PHL
1 stop8h 15m
Frontier
Mon 4/67:11 pm
PHL
- STL
1 stop16h 19m
Frontier
Deal found 3/6![Frontier logo]()
$182
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/38:16 pm
STL
- PHL
1 stop8h 15m
Frontier
Wed 4/87:10 pm
PHL
- STL
1 stop23h 24m
Frontier
Deal found 3/6![Frontier logo]()
$183
This Priceline deal was found by Cheapflights users on 3/6. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/88:16 pm
STL
- PHL
1 stop8h 15m
Frontier
Sat 4/114:11 pm
PHL
- STL
1 stop8h 14m
Frontier
Deal found 3/6![Frontier logo]()
$160
This CheapOair deal was found by Cheapflights users on 3/9. 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.
Wed 4/88:16 pm
STL
- PHL
1 stop8h 15m
Frontier
Wed 4/158:41 pm
PHL
- STL
1 stop23h 40m
Frontier
Deal found 3/9![Frontier logo]()
$171
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Tue 4/217:10 pm
PHL
- STL
1 stop12h 40m
Frontier
Deal found 3/6![Frontier logo]()
$149
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Wed 4/2211:02 am
PHL
- STL
1 stop24h 28m
Frontier
Deal found 3/6![Frontier logo]()
$161
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
- PHL
1 stop10h 47m
Multiple Airlines
Sun 4/197:00 am
PHL
- STL
1 stop24h 50m
Multiple Airlines
Deal found 3/6![Multiple Airlines logo]()
$188
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Sun 4/197:45 am
PHL
- STL
2 stops24h 05m
Frontier
Deal found 3/6![Frontier logo]()
$193
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/188:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Tue 4/217:10 pm
PHL
- STL
1 stop12h 40m
Frontier
Deal found 3/6![Frontier logo]()
$176
This Booking.com deal was found by Cheapflights users on 3/8. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/228:23 pm
STL
- PHL
1 stop10h 47m
Frontier
Wed 4/297:56 pm
PHL
- STL
1 stop28h 23m
Frontier
Deal found 3/8![Frontier logo]()
$172
This Frontier deal was found by Cheapflights users on 3/6. 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.
Thu 4/3011:21 am
STL
- PHL
1 stop6h 58m
Frontier
Sat 5/24:42 pm
PHL
- STL
1 stop7h 37m
Frontier
Deal found 3/6![Frontier logo]()
$181
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 March 10, 2026.
Search for one-way flight options from St. Louis to Philadelphia. Find affordable one-way fares based on user searches. Data last updated March 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 3/9. 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 5/98:12 pm
STL
- PHL
1 stop8h 22m
Frontier
Deal found 3/9![Frontier logo]()
$77
This Priceline deal was found by Cheapflights users on 3/5. 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.
Fri 5/88:12 pm
STL
- PHL
1 stop8h 22m
Frontier
Deal found 3/5![Frontier logo]()
$80
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/68:13 pm
STL
- PHL
1 stop10h 57m
Frontier
Deal found 3/6![Frontier logo]()
$83
This CheapOair deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/54:55 pm
STL
- PHL
1 stop16h 43m
Frontier
Deal found 3/6![Frontier logo]()
$92
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/711:21 am
STL
- PHL
2 stops20h 18m
Multiple Airlines
Deal found 3/6![Multiple Airlines logo]()
$95
This Frontier deal was found by Cheapflights users on 3/6. 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.
Fri 6/56:40 pm
STL
- PHL
1 stop11h 20m
Frontier
Deal found 3/6![Frontier logo]()
$101
This Kiwi.com deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/38:16 pm
STL
- PHL
1 stop8h 15m
Frontier
Deal found 3/6![Frontier logo]()
$105
This Frontier deal was found by Cheapflights users on 3/5. 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 6/22:17 pm
STL
- PHL
1 stop9h 47m
Frontier
Deal found 3/5![Frontier logo]()
$107
This Frontier deal was found by Cheapflights users on 3/6. 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.
Mon 4/68:19 pm
STL
- PHL
1 stop8h 12m
Frontier
Deal found 3/6![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 March 10, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $149 (Kiwi.com) |
One-way from | $77 (Kiwi.com) |
Popular in | November |
Cheapest in | August |
Average price | $461 |
Good round-trip deal | $480 or less |
Good one-way deal | $324 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 March 10, 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
Thu 4/23
8:06 pm-5:34 am
1 stop8h 28m
Philadelphia
Thu 4/30
10:38 pm-6:50 am
2 stops33h 12m
$265
Quickest round-trip
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Wed 4/8
1:40 pm-4:50 pm
Nonstop2h 10m
Philadelphia
Wed 4/15
6:35 pm-8:00 pm
Nonstop2h 25m
$277
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Wed 4/15
6:50 pm-10:00 pm
Nonstop2h 10m
Philadelphia
Mon 4/20
6:00 pm-10:45 pm
1 stop5h 45m
$298
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Mon 5/11
1:45 pm-9:45 pm
1 stop7h 00m
Philadelphia
Mon 5/18
7:10 pm-8:50 pm
Nonstop2h 40m
$309
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Thu 4/23
1:35 pm-4:45 pm
Nonstop2h 10m
Philadelphia
Thu 4/30
6:00 pm-10:45 pm
1 stop5h 45m
$309
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Wed 4/22
2:30 pm-10:00 pm
1 stop6h 30m
Philadelphia
Wed 4/29
6:35 pm-8:00 pm
Nonstop2h 25m
$309
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Mon 5/4
1:45 pm-10:45 pm
2 stops8h 00m
Philadelphia
Fri 5/8
12:45 pm-6:55 pm
2 stops7h 10m
$365
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Thu 5/7
7:35 am-3:50 pm
2 stops7h 15m
Philadelphia
Mon 5/11
11:10 am-6:55 pm
2 stops8h 45m
$365
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Fri 6/5
5:40 pm-9:09 pm
Nonstop2h 29m
Philadelphia
Mon 6/8
9:01 am-10:37 am
Nonstop2h 36m
$371
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
Thu 4/23
1:35 pm-4:45 pm
Nonstop2h 10m
Philadelphia
Sun 4/26
5:50 am-9:05 am
1 stop4h 15m
$381
Showing 1-10 of 22 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 March.
| 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
Prices
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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 March 6, 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 53 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, January is the cheapest month in which you can book a flight from St. Louis to Philadelphia (average of $121). Flying from St. Louis to Philadelphia in March is currently the most expensive (average of $245). 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 March 10, 2026.
It’s typically best to fly out from St. Louis to Philadelphia in the evening. Doing so could potentially save you 63% 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 February 21, 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. Friday 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 March 10, 2026.
Read reviews from past customers who have flown Southwest,American Airlines, andSpirit 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
Food
7.0
Overall
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
10.0
ExcellentAnonymous,Mar 2026
KOA - HNL
Comfort
8.0
Food
7.0
Overall
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
10.0
ExcellentAnonymous,Mar 2026
KOA - HNL
Comfort
8.0
Food
7.0
Overall
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
10.0
ExcellentAnonymous,Mar 2026
KOA - HNL
Comfort
8.0
Food
7.0
Overall
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
10.0
ExcellentAnonymous,Mar 2026
KOA - HNL
Comfort
8.0
Food
7.0
Overall
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
10.0
ExcellentAnonymous,Mar 2026
KOA - HNL
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
Reading
King of Prussia
Camden
Ocean City
Cherry Hill
Lewes
Dewey Beach
Pottstown
Ephrata
Vineland
Milford
Dover
Elkton
Essington
Willow Grove
New Castle
Millville
Glen Mills
Chester
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St. Louis and Philadelphia flights
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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 March 10, 2026.
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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 March 10, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$82 | Average$219 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$142 | Average$236 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$240 | Average$425 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$275 | Average$432 | FlexibilityNo cancel fee | On-time63% |