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Cheap flights from Seattle to Philadelphia from C$ 210

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 12/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — PHL
15 Oct — 22 Oct1
1 adult
1 adult, Economy

Cheap flight deals from Seattle to Philadelphia

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) 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 15 September 2025.

Round-trip from

C$ 383

One-way from

C$ 210

Popular in

December

Cheapest in

March

Average price

C$ 577
Alaska Airlines
  • Alaska Airlines
  • 18/11-23/11
  • Nonstop
  • 11h 19m total
  • Seattle to Philadelphia
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United Airlines
  • United Airlines
  • 12/3
  • 1 total stop
  • 7h 06m total
  • Seattle to Philadelphia
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Highest demand for flights based on searches. 5% potential increase in price (C$ 53 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease (C$ 26 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from Seattle to Philadelphia

Cheapest flights from Seattle to Philadelphia
Explore the most affordable flight options available from Seattle to Philadelphia. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 15 September 2025.

Thu 20/117:12 p.m.SEA - PHL
1 stop7h 43mDelta
Sun 23/117:10 a.m.PHL - SEA
1 stop8h 46mDelta
Deal found 15/9C$ 383
Mon 15/129:35 p.m.SEA - PHL
Nonstop5h 11mAlaska Airlines
Sun 1/26:35 p.m.PHL - SEA
Nonstop6h 12mAlaska Airlines
Deal found 14/9C$ 397
Mon 15/125:40 a.m.SEA - PHL
1 stop13h 55mSouthwest
Tue 23/125:40 p.m.PHL - SEA
1 stop9h 55mSouthwest
Deal found 13/9C$ 404
Wed 29/109:59 a.m.SEA - PHL
Nonstop5h 13mAlaska Airlines
Fri 31/107:02 a.m.PHL - SEA
Nonstop6h 11mAlaska Airlines
Deal found 14/9C$ 411
Mon 15/125:40 a.m.SEA - PHL
1 stop13h 55mSouthwest
Sun 1/25:00 a.m.PHL - SEA
1 stop8h 25mSouthwest
Deal found 14/9C$ 418
Mon 15/127:29 p.m.SEA - PHL
2 stops11h 06mUnited Airlines
Sun 1/26:30 a.m.PHL - SEA
1 stop8h 02mUnited Airlines
Deal found 14/9C$ 424
Sun 12/109:23 p.m.SEA - PHL
Nonstop5h 17mHawaiian Airlines
Thu 23/107:11 p.m.PHL - SEA
Nonstop6h 18mHawaiian Airlines
Deal found 13/9C$ 425
Sat 1/115:45 a.m.SEA - PHL
1 stop11h 45mSouthwest
Thu 6/1112:35 p.m.PHL - SEA
1 stop10h 25mSouthwest
Deal found 13/9C$ 432
Thu 30/106:22 p.m.SEA - PHL
1 stop12h 11mSun Country Air
Sun 2/1110:00 a.m.PHL - SEA
1 stop10h 15mSun Country Air
Deal found 14/9C$ 436
Fri 14/116:35 a.m.SEA - PHL
1 stop8h 45mSouthwest
Fri 21/113:20 p.m.PHL - SEA
1 stop7h 40mSouthwest
Deal found 13/9C$ 439

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle 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 629,999 searches. Data last updated 15 September 2025.
Use the filters below to find and compare flights from Seattle to Philadelphia that are best for you.

Fly from

Seattle

Fly to

Philadelphia

Route

Depart

Return

Price

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Wed 19/11

1:39 p.m.-11:50 p.m.

1 stop7h 11m

Philadelphia

Sun 23/11

6:00 a.m.-10:54 a.m.

1 stop7h 54m

C$ 383

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Wed 22/10

6:00 a.m.-4:35 p.m.

1 stop7h 35m

Philadelphia

Tue 28/10

5:02 p.m.-11:54 p.m.

1 stop9h 52m

C$ 383

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 10/10

7:18 p.m.-5:50 a.m.

1 stop7h 32m

Philadelphia

Fri 17/10

6:50 p.m.-11:59 p.m.

1 stop8h 09m

C$ 383

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 20/11

7:12 p.m.-5:55 a.m.

1 stop7h 43m

Philadelphia

Sun 23/11

7:10 a.m.-12:56 p.m.

1 stop8h 46m

C$ 383

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 17/10

7:18 p.m.-5:50 a.m.

1 stop7h 32m

Philadelphia

Tue 21/10

7:00 p.m.-11:57 p.m.

1 stop7h 57m

C$ 383

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Sat 18/10

7:10 a.m.-5:38 p.m.

1 stop7h 28m

Philadelphia

Sun 26/10

6:00 a.m.-10:33 a.m.

1 stop7h 33m

C$ 383

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 10/10

7:18 p.m.-5:50 a.m.

1 stop7h 32m

Philadelphia

Tue 14/10

6:00 a.m.-10:33 a.m.

1 stop7h 33m

C$ 383

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Mon 15/12

9:35 p.m.-5:46 a.m.

Nonstop5h 11m

Philadelphia

Sun 1/2

6:35 p.m.-9:47 p.m.

Nonstop6h 12m

C$ 397

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Mon 15/12

5:40 a.m.-10:35 p.m.

1 stop13h 55m

Philadelphia

Sun 1/2

5:00 a.m.-10:25 a.m.

1 stop8h 25m

C$ 418

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Wed 4/3

9:15 a.m.-5:31 p.m.

Nonstop5h 16m

Philadelphia

Wed 11/3

6:35 p.m.-9:47 p.m.

Nonstop6h 12m

C$ 425

Flights are sorted by cheapest round-trip flights first.

Deals found on 13/9

Showing 1-10 of 20 results
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Best time to book a flight from Seattle to Philadelphia

Have a flexible travel schedule? Discover the best time to fly to Philadelphia from Seattle 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 Seattle to Philadelphia

How far ahead should I book a flight from Seattle to Philadelphia?

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Philadelphia. Price data was last updated on 12 September 2025.

The best time to book flights from Seattle to Philadelphia is 86 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.

What is the cheapest month to book a flight from Seattle to Philadelphia?

Currently, January is the cheapest month in which you can book a flight from Seattle to Philadelphia (average of C$ 388). Flying from Seattle to Philadelphia in September is currently the most expensive (average of C$ 418). 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 SEA to PHL?

Find hourly flight availability from Seattle 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 15 September 2025.

One of the essential ways to save on airfare from Seattle to Philadelphia is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight at noon could potentially save you up to 54% on airfare.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Philadelphia. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How popular is this Seattle to Philadelphia flight route?

    This flight path from Seattle/Tacoma Intl to Philadelphia was viewed by 7 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • How long is the flight from Seattle to Philadelphia?

    For as low as C$ 383, Delta can have you in Philadelphia from Seattle in 6h 26m. Seattle and Philadelphia are separated by a distance of 3814 km.

  • What are the most reliable airlines from Seattle to Philadelphia?

    Before booking your flight to Philadelphia from Seattle, check out the most reliable airlines to get you to your destination on time: Hawaiian Airlines (77%), Finnair (75%), American Airlines( 71%).

  • Can I find deals for flights from Seattle to Philadelphia that include hotel bookings?

    Yes. In addition to deals on Seattle to Philadelphia flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Philadelphia?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Philadelphia.

  • Can I find deals for business class flights from Seattle to Philadelphia?

    Yes. Cheapflights offers flight deals from Seattle to Philadelphia by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Seattle to Philadelphia?

    Currently, January is the cheapest month in which you can book a flight from Seattle to Philadelphia (average of C$ 388). Flying from Seattle to Philadelphia in September is currently the most expensive (average of C$ 418). 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.

See more FAQs

Travelling to a place near Philadelphia?

Book flights to Philadelphia if you plan to visit one of these locations
King of Prussia
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