Plan to arrive at SEA at least two hours before your flight. Use SEA Spot Saver for security screening appointments to save time.

Most accurate provider | eDreams 3 stars |
|---|---|
Most trusted provider | eDreams 3 stars |
Round-trip from | $257 (Priceline) |
One-way from | $139 (Delta) |
Popular in | December |
Cheapest in | October |
Average price | $446 |
Good round-trip deal | $329 or less |
Good one-way deal | $191 or less |
Fly from
Fly to
Route
Depart
Return
Price
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Tue 12/2
5:25 am-5:40 pm
1 stop9h 15m
Philadelphia
Fri 12/12
6:30 pm-12:24 am
1 stop8h 54m
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Thu 12/4
9:35 pm-5:46 am
Nonstop5h 11m
Philadelphia
Sat 12/6
6:54 pm-10:12 pm
Nonstop6h 18m
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Sat 12/6
5:00 am-3:00 pm
1 stop7h 00m
Philadelphia
Sun 12/7
6:35 pm-12:35 am
1 stop9h 00m
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 12/10
7:00 am-5:39 pm
1 stop7h 39m
Philadelphia
Sat 12/13
6:30 am-11:47 am
1 stop8h 17m
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 12/3
5:25 am-5:40 pm
1 stop9h 15m
Philadelphia
Sat 12/6
6:18 am-10:54 am
1 stop7h 36m
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Mon 1/5
12:00 pm-11:57 pm
1 stop8h 57m
Philadelphia
Sat 1/10
10:30 am-7:00 pm
1 stop11h 30m
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Fri 12/5
2:03 pm-12:51 am
1 stop7h 48m
Philadelphia
Mon 12/8
5:17 pm-10:25 pm
1 stop8h 08m
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 12/3
11:55 pm-10:51 am
1 stop7h 56m
Philadelphia
Sun 12/7
6:07 pm-11:58 pm
1 stop8h 51m
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 12/10
7:25 am-6:12 pm
1 stop7h 47m
Philadelphia
Sun 12/14
6:18 am-10:54 am
1 stop7h 36m
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Tue 12/2
5:25 am-5:40 pm
1 stop9h 15m
Philadelphia
Mon 12/8
6:00 am-10:40 am
1 stop7h 40m
| 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 Accuracy3 stars | Trust Score*2 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy- | Trust Score*1 star |
The best time to book flights from Seattle to Philadelphia is 59 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
Currently, November is the cheapest month in which you can book a flight from Seattle to Philadelphia (average of $128). Flying from Seattle to Philadelphia in January is currently the most expensive (average of $223). 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.
A simple way to save on the total cost of your ticket is to fly from Seattle to Philadelphia at noon. If you’re flexible enough to do this you can expect to save up to 52% on your trip compared to booking a flight in the afternoon.
Travelers seeking maximum savings on their Seattle to Philadelphia flight should consider departing on Wednesday afternoons 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.
Boarding
Crew
Entertainment
Comfort
Overall
Food
Reviews
Anonymous,Sep 2025
SEA - MKE
Boarding
Crew
Entertainment
Comfort
Overall
Food
Reviews
Anonymous,Sep 2025
SEA - MKE
Boarding
Crew
Entertainment
Comfort
Overall
Food
Reviews
Anonymous,Sep 2025
SEA - MKE
Boarding
Crew
Entertainment
Comfort
Overall
Food
Reviews
Anonymous,Sep 2025
SEA - MKE
Boarding
Crew
Entertainment
Comfort
Overall
Food
Reviews
Anonymous,Sep 2025
SEA - MKE
Boarding
Crew
Entertainment
Comfort
Overall
Food
Reviews
Anonymous,Sep 2025
SEA - MKE
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$131 | Average$292 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$138 | Average$258 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$206 | Average$389 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$221 | Average$370 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$233 | Average$355 | FlexibilityNo cancel fee | On-time83% | |
| Cheapest$277 | Average$534 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$277 | Average$542 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$277 | Average$415 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$351 | Average$429 | FlexibilityNo cancel fee | On-time63% |