HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Philadelphia

$165+ 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 9/4. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — PHL
Aug 22 — Aug 291
Sat 8/22
Sat 8/29
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Seattle to Philadelphia with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.
Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Philadelphia are usually found in October or January, booked 81 days in advance, depart on a Tuesday or Thursday and return on a Wednesday

Cheap 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 July 23, 2026.

This Alaska Airlines deal was found by Cheapflights users on 7/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/49:27 pm
SEA
-
PHL
Nonstop5h 13m
Alaska Airlines
Wed 9/97:00 am
PHL
-
SEA
Nonstop5h 51m
Alaska Airlines
Deal found 7/21$329
This Justfly.com deal was found by Cheapflights users on 7/19. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2011:55 pm
SEA
-
PHL
1 stop11h 35m
Multiple Airlines
Sat 11/74:25 pm
PHL
-
SEA
1 stop9h 09m
Multiple Airlines
Deal found 7/19$330
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 8/147:06 pm
SEA
-
PHL
1 stop7h 33m
Frontier
Fri 8/214:45 pm
PHL
-
SEA
2 stops43h 34m
Frontier
Deal found 7/20$331
This Frontier deal was found by Cheapflights users on 7/20. 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 8/37:06 pm
SEA
-
PHL
1 stop7h 33m
Frontier
Fri 8/148:37 pm
PHL
-
SEA
1 stop15h 27m
Frontier
Deal found 7/20$332
This Expedia deal was found by Cheapflights users on 7/20. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/188:53 pm
SEA
-
PHL
1 stop30h 37m
Multiple Airlines
Tue 8/256:59 pm
PHL
-
SEA
Nonstop5h 52m
Multiple Airlines
Deal found 7/20$333
This CheapOair deal was found by Cheapflights users on 7/22. 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.
Wed 8/52:22 pm
SEA
-
PHL
1 stop18h 27m
Frontier
Sat 8/811:06 am
PHL
-
SEA
1 stop26h 58m
Frontier
Deal found 7/22$334
This CheapOair deal was found by Cheapflights users on 7/20. 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 8/118:13 pm
SEA
-
PHL
1 stop30h 47m
Frontier
Tue 8/188:37 pm
PHL
-
SEA
1 stop15h 42m
Frontier
Deal found 7/20$335
This CheapOair deal was found by Cheapflights users on 7/20. 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.
Thu 8/68:53 pm
SEA
-
PHL
1 stop30h 07m
Frontier
Sat 8/1511:06 am
PHL
-
SEA
1 stop26h 58m
Frontier
Deal found 7/20$336
This Kiwi.com deal was found by Cheapflights users on 7/20. 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.
Wed 9/27:06 pm
SEA
-
PHL
1 stop7h 33m
Multiple Airlines
Mon 9/217:00 am
PHL
-
SEA
Nonstop5h 51m
Multiple Airlines
Deal found 7/20$337
This Expedia deal was found by Cheapflights users on 7/22. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/198:53 pm
SEA
-
PHL
1 stop30h 37m
Multiple Airlines
Wed 8/267:02 am
PHL
-
SEA
Nonstop5h 51m
Multiple Airlines
Deal found 7/22$338
This Alaska Airlines deal was found by Cheapflights users on 7/22. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/49:27 pm
SEA
-
PHL
Nonstop5h 13m
Alaska Airlines
Sun 9/64:48 pm
PHL
-
SEA
1 stop8h 51m
Alaska Airlines
Deal found 7/22$339
This CheapOair deal was found by Cheapflights users on 7/22. 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 8/147:06 pm
SEA
-
PHL
1 stop7h 33m
Frontier
Thu 8/207:00 am
PHL
-
SEA
1 stop30h 39m
Frontier
Deal found 7/22$340

Find 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 July 23, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$329
(Alaska Airlines)

One-way from

$165
(Delta)

Popular in

December

Cheapest in

October

Average price

$417

Good round-trip deal

$380 or less

Good one-way deal

$207 or less
Provider with most accurate pricing for Seattle/Tacoma Intl-Philadelphia flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Philadelphia flights.
Search Deals
From Seattle/Tacoma Intl to Philadelphia
Search Deals
One-way flight from Seattle/Tacoma Intl to Philadelphia
Search Deals
Highest demand for flights based on searches. 0% potential increase in price ($3 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($10 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 2026
Search Deals
Price to beat on a round-trip flight from Seattle/Tacoma Intl to Philadelphia.
Search Deals
Price to beat on a one-way flight from Seattle/Tacoma Intl to Philadelphia.
Search Deals

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 July 23, 2026.
Use the filters below to find and compare flights from Seattle to Philadelphia that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 10/16

9:31 pm-5:45 am

Nonstop5h 14m

Philadelphia

Sun 10/18

7:00 am-9:58 am

Nonstop5h 58m

$329

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Sat 10/10

9:31 pm-5:45 am

Nonstop5h 14m

Philadelphia

Mon 10/12

7:00 am-9:58 am

Nonstop5h 58m

$329

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Sun 11/22

9:50 pm-6:03 am

Nonstop5h 13m

Philadelphia

Fri 11/27

7:05 am-10:24 am

Nonstop6h 19m

$329
Quickest round-trip

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 10/22

9:29 pm-5:41 am

Nonstop5h 12m

Philadelphia

Sun 10/25

7:02 am-9:55 am

Nonstop5h 53m

$339

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 11/20

7:35 pm-5:41 am

1 stop7h 06m

Philadelphia

Mon 11/23

7:05 am-10:24 am

Nonstop6h 19m

$339

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 10/22

9:31 pm-5:45 am

Nonstop5h 14m

Philadelphia

Sun 10/25

7:00 am-9:58 am

Nonstop5h 58m

$339

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Mon 11/2

11:45 am-11:12 pm

1 stop8h 27m

Philadelphia

Fri 11/6

7:00 am-9:58 am

Nonstop5h 58m

$339

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 9/10

8:20 pm-11:10 am

2 stops11h 50m

Philadelphia

Mon 9/14

2:05 pm-8:45 pm

2 stops9h 40m

$347

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Fri 11/20

9:10 am-11:15 pm

2 stops11h 05m

Philadelphia

Mon 11/23

6:25 pm-12:30 am

1 stop9h 05m

$369

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Sat 9/12

5:30 am-8:50 pm

2 stops12h 20m

Philadelphia

Sun 9/13

5:05 pm-11:15 pm

1 stop9h 10m

$374

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/18

Showing 1-10 of 22 resultsSorted by cheapest first
1
2
3

Compare providers for flights from Seattle to Philadelphia

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Philadelphia in July.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy2 starsTrust Score*3 stars
PricelinePrice Accuracy1 starTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Seattle-Philadelphia flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Philadelphia flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Philadelphia flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Philadelphia flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-Philadelphia flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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?

The best time to book flights from Seattle to Philadelphia is 80 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, October is the cheapest month in which you can book a flight from Seattle to Philadelphia (average of $329). Flying from Seattle to Philadelphia in December is currently the most expensive (average of $519). 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 July 23, 2026.

When flying from Seattle to Philadelphia, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

How much does it cost to fly round-trip from Seattle to Philadelphia?

Airfare is below average for this route at the moment.

Seattle to Philadelphia flights typically cost between $372 and $544 in August.
The cheapest round-trip price found within the last 5 days was $329 on Alaska Airlines (Aug 28-Sep 8).

The best insider tips for Seattle to Philadelphia flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to Philadelphia trip
Our travel experts
Mark Chesnut

Mark Chesnut

Expert on PHL

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 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

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 July 23, 2026.
Peruse reviews from past customers who have flown with Alaska Airlines,Delta, andUnited 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
7.9
Good
12,696 reviews

Comfort

7.8

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Overall

7.9

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
Alaska Airlines
7.9
Good
12,696 reviews
Alaska Airlines
7.9
Good
12,696 reviews

Comfort

7.8

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Overall

7.9

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
Delta
7.8
Good
8,480 reviews
Alaska Airlines
7.9
Good
12,696 reviews

Comfort

7.8

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Overall

7.9

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
United Airlines
7.4
Good
10,027 reviews
Alaska Airlines
7.9
Good
12,696 reviews

Comfort

7.8

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Overall

7.9

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
American Airlines
7.1
Good
11,833 reviews
Alaska Airlines
7.9
Good
12,696 reviews

Comfort

7.8

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Overall

7.9

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
Frontier
5.6
Fair
2,770 reviews
Alaska Airlines
7.9
Good
12,696 reviews

Comfort

7.8

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Overall

7.9

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.

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 09m 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 6 different airlines.

  • How popular is this Seattle to Philadelphia flight route?

    Flights from Seattle/Tacoma Intl to Philadelphia have been viewed 14 times in the past calendar month.

  • How long is the flight from Seattle to Philadelphia?

    Airlines like Delta and Alaska Airlines fly from Seattle to Philadelphia in about 5h 12m. The time it takes to get you to your destination is usually consistent. Seattle and Philadelphia are separated by a distance of 2370 mi. All flights are typically nonstop.

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

    Currently priced at $149, Frontier will fly you from Seattle to Philadelphia and back. In addition to Frontier, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Delta and United Airlines - these airlines can fly you to your destination from $158 and $206, respectively. Frontier is currently priced 63% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from Seattle to Philadelphia one-way?

    One-way options have recently been found by users for as low as $100 on Frontier. Other airlines that offer cheap prices include United Airlines from $128 and American Airlines from $139 one-way.

  • 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 KLM (100%), STARLUX Airlines (93%) or Finnair (86%) 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 $164. While the most popular route (Seattle/Tacoma Intl - Philadelphia) can be booked for $267 on average, our data indicates $782 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, October is the cheapest month in which you can book a flight from Seattle to Philadelphia (average of $329). Flying from Seattle to Philadelphia in December is currently the most expensive (average of $519). 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
Wildwood
King of Prussia
Reading
Camden
Ocean City
Cherry Hill
Lewes
Plymouth Meeting
Wyomissing
Wildwood Crest
Pottstown
Ephrata
Milford
Dover
Elkton
Essington
Willow Grove
New Castle
Millville
Vineland

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top 6 airlines flying from Seattle to Philadelphia

Discover the top 6 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 July 23, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$149Average$309FlexibilityNo cancel feeOn-time62%
DeltaCheapest$158Average$367FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$206Average$392FlexibilityNo cancel feeOn-time69%
Hawaiian AirlinesCheapest$257Average$464FlexibilityNo cancel feeOn-time85%
Alaska AirlinesCheapest$257Average$469FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$257Average$429FlexibilityNo cancel feeOn-time71%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.