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Cheap flights from Seattle to Philadelphia from C$ 171

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 4/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — PHL
5 Feb — 12 Feb1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Philadelphia are usually found in October or January, booked 69 days in advance, depart on a Tuesday or Monday and return on a Monday

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 6 January 2026.

Round-trip from

C$ 354

One-way from

C$ 171

Popular in

December

Cheapest in

October

Average price

C$ 504

Good round-trip deal

C$ 491 or less
Alaska Airlines
  • Alaska Airlines
  • 1/5-4/5
  • Nonstop
  • 11h 22m total
  • Seattle to Philadelphia
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United Airlines
  • United Airlines
  • 4/3
  • 1 total stop
  • 9h 14m total
  • Seattle to Philadelphia
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Highest demand for flights based on searches. 2% potential increase in price (C$ 20 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease (C$ 22 potential savings vs. average RT price).
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Average for round-trip flights in January 2026
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Price to beat on a round-trip flight from Seattle/Tacoma Intl to Philadelphia.
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Find flight deals from Seattle to Philadelphia

Enter your travel dates to find the best prices.

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 6 January 2026.

Fri 1/59:44 p.m.SEA - PHL
Nonstop5h 18mAlaska Airlines
Mon 4/56:58 p.m.PHL - SEA
Nonstop6h 04mAlaska Airlines
Deal found 5/1C$ 354
Fri 20/29:19 a.m.SEA - PHL
1 stop9h 14mUnited Airlines
Tue 24/23:05 p.m.PHL - SEA
2 stops10h 38mUnited Airlines
Deal found 5/1C$ 355
Sat 17/15:00 a.m.SEA - PHL
2 stops9h 34mUnited Airlines
Tue 20/16:30 a.m.PHL - SEA
1 stop8h 02mUnited Airlines
Deal found 5/1C$ 358
Tue 20/17:00 a.m.SEA - PHL
1 stop7h 34mUnited Airlines
Mon 2/23:01 p.m.PHL - SEA
2 stops10h 42mUnited Airlines
Deal found 4/1C$ 359
Wed 28/17:00 a.m.SEA - PHL
1 stop7h 33mUnited Airlines
Sat 31/16:30 a.m.PHL - SEA
2 stops12h 14mUnited Airlines
Deal found 6/1C$ 361
Sat 11/411:55 p.m.SEA - PHL
1 stop7h 45mSouthwest
Sat 18/45:00 p.m.PHL - SEA
1 stop8h 10mSouthwest
Deal found 4/1C$ 363
Sat 21/311:55 p.m.SEA - PHL
1 stop7h 50mSouthwest
Tue 24/32:10 p.m.PHL - SEA
2 stops11h 20mSouthwest
Deal found 4/1C$ 365
Fri 15/57:35 p.m.SEA - PHL
1 stop7h 08mDelta
Tue 26/57:05 a.m.PHL - SEA
Nonstop5h 59mDelta
Deal found 3/1C$ 368
Wed 25/29:19 a.m.SEA - PHL
1 stop9h 14mUnited Airlines
Fri 27/25:00 p.m.PHL - SEA
1 stop8h 43mUnited Airlines
Deal found 4/1C$ 379
Fri 22/59:27 p.m.SEA - PHL
Nonstop5h 13mAlaska Airlines
Sun 24/57:00 a.m.PHL - SEA
Nonstop5h 59mAlaska Airlines
Deal found 6/1C$ 381

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 6 January 2026.
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

Tue 3/2

11:10 p.m.-11:43 a.m.

1 stop9h 33m

Philadelphia

Tue 10/2

6:37 p.m.-12:09 a.m.

1 stop8h 32m

C$ 354

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 10/4

9:55 p.m.-6:05 a.m.

Nonstop5h 10m

Philadelphia

Tue 21/4

7:25 a.m.-10:30 a.m.

Nonstop6h 05m

C$ 354

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 27/3

11:15 p.m.-8:50 a.m.

1 stop6h 35m

Philadelphia

Tue 31/3

12:26 p.m.-6:26 p.m.

1 stop9h 00m

C$ 354

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 27/3

9:37 a.m.-5:47 p.m.

Nonstop5h 10m

Philadelphia

Tue 31/3

6:47 p.m.-9:52 p.m.

Nonstop6h 05m

C$ 354

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Tue 7/4

11:15 p.m.-8:50 a.m.

1 stop6h 35m

Philadelphia

Thu 30/4

7:05 a.m.-3:26 p.m.

1 stop11h 21m

C$ 354

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 26/2

5:30 a.m.-5:38 p.m.

1 stop9h 08m

Philadelphia

Mon 2/3

6:50 p.m.-12:09 a.m.

1 stop8h 19m

C$ 354

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 12/2

1:38 p.m.-11:46 p.m.

1 stop7h 08m

Philadelphia

Mon 16/2

6:50 p.m.-12:09 a.m.

1 stop8h 19m

C$ 354

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 30/1

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

1 stop9h 25m

Philadelphia

Sun 1/2

6:37 p.m.-12:09 a.m.

1 stop8h 32m

C$ 354

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Sun 25/1

11:10 p.m.-8:50 a.m.

1 stop6h 40m

Philadelphia

Sun 1/2

6:37 p.m.-12:09 a.m.

1 stop8h 32m

C$ 354

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Wed 25/2

11:20 a.m.-11:46 p.m.

1 stop9h 26m

Philadelphia

Tue 3/3

7:00 a.m.-2:44 p.m.

1 stop10h 44m

C$ 354

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/1

Showing 1-10 of 21 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 2 January 2026.

The best time to book flights from Seattle to Philadelphia is 69 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, December is the cheapest month in which you can book a flight from Seattle to Philadelphia (average of C$ 178). Flying from Seattle to Philadelphia in February is currently the most expensive (average of C$ 274). 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 6 January 2026.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Seattle to Philadelphia as you normally would.

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 5 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$ 354, Delta can have you in Philadelphia from Seattle in 5h 10m. Seattle and Philadelphia are separated by a distance of 3814 km. This flight may include one or multiple stops.

  • 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: Alaska Airlines (84%), Hawaiian Airlines (84%), Air Tahiti Nui( 84%).

  • What are the cheapest flights from Seattle to Philadelphia?

    Looking for the cheapest flight from Seattle to Philadelphia? While on average our users pay C$ 500, our data indicates the cheapest price to be C$ 380. The most popular route (Seattle/Tacoma Intl - Philadelphia), is priced around C$ 354.

  • 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, December is the cheapest month in which you can book a flight from Seattle to Philadelphia (average of C$ 178). Flying from Seattle to Philadelphia in February is currently the most expensive (average of C$ 274). 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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