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.

Most accurate provider | eDreams 3 stars |
|---|---|
Most trusted provider | eDreams 3 stars |
Round-trip from | $110 (Priceline) |
One-way from | $48 (Kiwi.com) |
Popular in | March |
Cheapest in | August |
Average price | $398 |
Good round-trip deal | $446 or less |
Good one-way deal | $221 or less |
Fly from
Fly to
Route
Depart
Return
Price
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
mar. 12/9
3:30 pm-12:40 am
1 stop8h 10m
Philadelphia
sáb. 12/13
10:00 pm-8:59 am
1 stop11h 59m
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
sáb. 11/22
7:43 pm-4:50 am
1 stop8h 07m
Philadelphia
mar. 11/25
5:46 am-2:29 pm
1 stop9h 43m
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
vie. 12/12
3:30 pm-12:40 am
1 stop8h 10m
Philadelphia
sáb. 12/13
10:00 pm-8:59 am
1 stop11h 59m
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
jue. 11/20
3:14 pm-12:30 am
1 stop8h 16m
Philadelphia
lun. 11/24
4:14 pm-11:57 pm
1 stop8h 43m
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
lun. 12/15
10:47 am-12:36 am
2 stops12h 49m
Philadelphia
vie. 12/19
8:36 pm-10:02 am
1 stop14h 26m
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
mar. 12/9
8:15 am-11:25 am
Nonstop2h 10m
Philadelphia
sáb. 12/13
7:00 am-2:55 pm
1 stop8h 55m
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
lun. 12/22
5:30 am-8:47 am
Nonstop2h 17m
Philadelphia
mié. 12/24
6:00 am-2:09 pm
1 stop9h 09m
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
sáb. 2/28
10:18 am-4:38 pm
1 stop5h 20m
Philadelphia
mar. 3/3
8:00 am-2:49 pm
1 stop7h 49m
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
lun. 1/12
8:20 am-5:05 pm
2 stops7h 45m
Philadelphia
jue. 1/15
5:25 am-12:30 pm
2 stops8h 05m
St. LouisPhiladelphia
STL - PHL
STLPHL
Lambert-St Louis
jue. 12/4
3:30 pm-12:40 am
1 stop8h 10m
| 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 Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*2 stars | |
| Price Accuracy- | Trust Score*1 star |
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.
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 November is currently the most expensive (average of $209). 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.
It’s typically best to fly out from St. Louis to Philadelphia in the evening. Doing so could potentially save you 62% on the flight price compared to flying at noon, which is usually more expensive.
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.
Detroit (DTW) – chosen by Cheapflights users on 71% of 1-stop itineraries from St. Louis to Philadelphia on Cheapflights.
Flights via Orlando (MCO) have the shortest average one-way travel time for 1-stop routes: 6h 14m.
Flights via Orlando (MCO) have the shortest average one-way travel time for 1-stop routes: 6h 14m.
Flights via Orlando (MCO) offer the fastest connection on this route, with an average layover time of 2h 19m.
Crew
Food
Entertainment
Boarding
Comfort
Overall
Reviews
Mike,Aug 2025
OKC - AUS
Crew
Food
Entertainment
Boarding
Comfort
Overall
Reviews
Mike,Aug 2025
OKC - AUS
Crew
Food
Entertainment
Boarding
Comfort
Overall
Reviews
Mike,Aug 2025
OKC - AUS
Crew
Food
Entertainment
Boarding
Comfort
Overall
Reviews
Mike,Aug 2025
OKC - AUS
Crew
Food
Entertainment
Boarding
Comfort
Overall
Reviews
Mike,Aug 2025
OKC - AUS
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$106 | Average$219 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$130 | Average$229 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$243 | Average$418 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$297 | Average$422 | FlexibilityNo cancel fee | On-time63% |