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$149+ Cheap flights from Seattle to Philadelphia (SEA - 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 11/13. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — PHL
Oct 16 — Oct 231
Thu 10/16
Thu 10/23
1 adult, Economy
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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Philadelphia are usually found in March or January, booked 86 days in advance, depart on a Wednesday or Tuesday and return on a Thursday

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 September 16, 2025.

Round-trip from

$277
(Delta)

One-way from

$149
(Alaska Airlines)

Popular in

December

Cheapest in

March

Average price

$417

Good round-trip deal

$315 or less

Good one-way deal

$198 or less
From Seattle/Tacoma Intl to Philadelphia
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One-way flight from Seattle/Tacoma Intl to Philadelphia
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Highest demand for flights based on searches. 6% potential increase in price ($28 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($13 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from Seattle/Tacoma Intl to Philadelphia.
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Price to beat on a one-way flight from Seattle/Tacoma Intl to Philadelphia.
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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 September 16, 2025.

This Delta deal was found by Cheapflights users on 9/15. 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 11/207:12 pmSEA - PHL
1 stop7h 43mDelta
Mon 11/247:10 amPHL - SEA
1 stop10h 44mDelta
Deal found 9/15$277
This CheapOair deal was found by Cheapflights users on 9/16. 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 9/307:00 amSEA - PHL
2 stops27h 50mFrontier
Sat 10/117:10 pmPHL - SEA
2 stops39h 23mFrontier
Deal found 9/16$280
This Kiwi.com deal was found by Cheapflights users on 9/13. 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.
Sun 10/128:43 pmSEA - PHL
2 stops34h 51mFrontier
Thu 10/236:42 amPHL - SEA
1 stop27h 51mFrontier
Deal found 9/13$281
This CheapOair deal was found by Cheapflights users on 9/14. 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.
Fri 11/78:22 pmSEA - PHL
2 stops32h 59mFrontier
Sat 11/156:26 pmPHL - SEA
2 stops20h 47mFrontier
Deal found 9/14$282
This CheapOair deal was found by Cheapflights users on 9/14. 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 10/1310:16 amSEA - PHL
2 stops29h 28mFrontier
Mon 10/205:20 amPHL - SEA
2 stops33h 47mFrontier
Deal found 9/14$283
This Frontier deal was found by Cheapflights users on 9/15. 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 10/66:12 amSEA - PHL
2 stops15h 24mFrontier
Thu 10/96:32 amPHL - SEA
1 stop8h 35mFrontier
Deal found 9/15$284
This CheapOair deal was found by Cheapflights users on 9/15. 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 10/211:02 pmSEA - PHL
2 stops17h 25mFrontier
Wed 10/295:27 pmPHL - SEA
2 stops21h 46mFrontier
Deal found 9/15$285
This Kiwi.com deal was found by Cheapflights users on 9/14. 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 11/142:22 pmSEA - PHL
1 stop11h 27mFrontier
Wed 11/198:00 amPHL - SEA
2 stops30h 56mFrontier
Deal found 9/14$287
This CheapOair deal was found by Cheapflights users on 9/14. 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.
Sat 10/47:00 amSEA - PHL
2 stops23h 15mFrontier
Wed 10/85:53 pmPHL - SEA
2 stops21h 14mFrontier
Deal found 9/14$288
This Hawaiian Airlines deal was found by Cheapflights users on 9/15. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/229:45 amSEA - PHL
Nonstop5h 26mHawaiian Airlines
Wed 10/227:11 pmPHL - SEA
Nonstop6h 18mHawaiian Airlines
Deal found 9/15$291
This Southwest deal was found by Cheapflights users on 9/13. 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 12/155:40 amSEA - PHL
1 stop13h 55mSouthwest
Tue 12/235:40 pmPHL - SEA
1 stop9h 55mSouthwest
Deal found 9/13$292

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 2,558,603 searches. Data last updated September 16, 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 11/19

1:39 pm-11:50 pm

1 stop7h 11m

Philadelphia

Sun 11/23

6:00 am-10:54 am

1 stop7h 54m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 10/10

9:23 pm-5:40 am

Nonstop5h 17m

Philadelphia

Tue 10/14

7:00 am-9:49 am

Nonstop5h 49m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 12/11

9:35 pm-5:46 am

Nonstop5h 11m

Philadelphia

Tue 12/16

6:54 pm-10:12 pm

Nonstop6h 18m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Mon 10/6

11:40 pm-11:56 am

1 stop9h 16m

Philadelphia

Thu 10/9

6:34 am-2:24 pm

1 stop10h 50m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 10/10

11:55 pm-10:56 am

1 stop8h 01m

Philadelphia

Fri 10/17

6:50 pm-11:59 pm

1 stop8h 09m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Wed 11/5

1:40 pm-12:52 am

1 stop8h 12m

Philadelphia

Sun 11/9

6:47 pm-12:11 am

1 stop8h 24m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 11/20

7:12 pm-5:55 am

1 stop7h 43m

Philadelphia

Sun 11/23

7:10 am-12:56 pm

1 stop8h 46m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 11/21

5:00 pm-5:55 am

1 stop9h 55m

Philadelphia

Mon 11/24

7:10 am-2:54 pm

1 stop10h 44m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Sat 10/4

6:00 am-6:06 pm

1 stop9h 06m

Philadelphia

Wed 10/8

6:00 am-10:45 am

1 stop7h 45m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 11/21

5:00 pm-5:55 am

1 stop9h 55m

Philadelphia

Sun 11/23

7:10 am-2:54 pm

1 stop10h 44m

$277

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/16

Showing 1-10 of 22 results
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The best insider tips for Seattle to Philadelphia flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to Philadelphia trip
Airports
SEA

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

Read more about SEAby Brandon Schultz
PHL

For a quick trip to Center City, take the SEPTA Airport Line. It's efficient and operates from 5:00 a.m. to midnight.

Read more about PHLby Mark Chesnut
Our travel experts
Mark Chesnut

Mark Chesnut

Expert on PHL

Mark Chesnut

Mark Chesnut

Mark Chesnut is a travel writer and public speaker with more than 30 years of experience. The 2019 winner of the NLGJA Excellence in Travel Writing Award, Mark is the author of the book “Prepare for Departure” and has covered air travel for multiple top consumer and trade media outlets.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz

Brandon Schultz

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

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 September 12, 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, August is the cheapest month in which you can book a flight from Seattle to Philadelphia (average of $236). Flying from Seattle to Philadelphia in March is currently the most expensive (average of $295). 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 September 16, 2025.

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 53% on your trip compared to booking a flight in the afternoon.

What is the cheapest day to fly from Seattle to Philadelphia?

Use this chart to determine the cheapest time to fly round-trip from Seattle to Philadelphia. Price data was last updated on September 14, 2025.

Travelers seeking maximum savings on their Seattle to Philadelphia flight should consider departing on Wednesday afternoons when fares are most often at their lowest. Saturday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

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 September 16, 2025.
Peruse reviews from past customers who have flown with Alaska Airlines, Delta, and Hawaiian Airlines from Seattle to Philadelphia to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Crew

8.5

Overall

8.0

Food

7.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Crew

8.5

Overall

8.0

Food

7.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Delta
8.0
Very good
7,957 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Crew

8.5

Overall

8.0

Food

7.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Hawaiian Airlines
7.8
Good
2,724 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Crew

8.5

Overall

8.0

Food

7.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Crew

8.5

Overall

8.0

Food

7.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Frontier
5.8
Fair
3,174 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Crew

8.5

Overall

8.0

Food

7.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

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.

  • What airports do I use to fly from Seattle to Philadelphia?

    To fly from Seattle to Philadelphia, you need to book a flight from Seattle/Tacoma Intl (SEA) to Philadelphia (PHL). Nonstop flights to Philadelphia from Seattle/Tacoma Intl take 5h 08m on average. When it comes time to book airfare, you have a few options: there are 8 outbound flights from Seattle/Tacoma Intl to Philadelphia offered by 8 different airlines.

  • How popular is this Seattle to Philadelphia flight route?

    Flights from Seattle/Tacoma Intl to Philadelphia have been viewed 9 times in the past calendar month.

  • How long is the flight from Seattle to Philadelphia?

    Airlines like Delta and Hawaiian Airlines fly from Seattle to Philadelphia in about 5h 17m. The time it takes to get you to your destination can typically vary by up to 1h 54m. Seattle and Philadelphia are separated by a distance of 2370 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines flying from Seattle to Philadelphia round-trip?

    Currently priced at $114, Spirit Airlines will fly you from Seattle to Philadelphia and back. In addition to Spirit Airlines, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Frontier and United Airlines - these airlines can fly you to your destination from $131 and $223, respectively. Spirit Airlines is currently priced 74% below the average price you’ll pay for this route.

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

    No one likes to see their flight delayed. When booking a flight from Seattle to Philadelphia consider choosing Hawaiian Airlines (77%), Finnair (75%) or American Airlines (71%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Seattle to Philadelphia?

    Looking at all options, your cheapest flight can be booked for $133. While the most popular route (Seattle/Tacoma Intl - Philadelphia) can be booked for $241 on average, our data indicates $939 when flying from Seattle to Philadelphia.

  • 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, August is the cheapest month in which you can book a flight from Seattle to Philadelphia (average of $236). Flying from Seattle to Philadelphia in March is currently the most expensive (average of $295). 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

Traveling to a place near Philadelphia?

Book flights to Philadelphia if you plan to visit one of these locations
Vineland
Wildwood
King of Prussia
Pottstown
Reading
Dewey Beach
Ephrata
Camden
Ocean City
Cherry Hill
Dover
Elkton
Essington
Willow Grove
Newark
Millville
Chester
Exton
Havre de Grace
Plymouth Meeting

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Seattle to Philadelphia

See prices for flight routes from nearby airports that may be better suited for you.
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Top 8 airlines flying from Seattle to Philadelphia

Discover the top 8 airlines that operate flights from Seattle 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 September 16, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$114Average$258FlexibilityNo cancel feeOn-time65%
FrontierCheapest$131Average$284FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$223Average$414FlexibilityNo cancel feeOn-time69%
DeltaCheapest$235Average$377FlexibilityNo cancel feeOn-timeN/A
Hawaiian AirlinesCheapest$277Average$540FlexibilityNo cancel feeOn-time85%
Alaska AirlinesCheapest$278Average$537FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$278Average$417FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$349Average$432FlexibilityNo cancel feeOn-time63%

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