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Cheap flights from Philadelphia to Seattle from $139

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Philadelphia to Seattle departing on 9/24. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Cheap round-trip flights

Alaska Airlines Logo
7:22 am - 10:18 amPHL-SEA
5h 56mnonstop
Alaska Airlines Logo
9:23 pm - 5:40 amSEA-PHL
5h 17mnonstop
$277Alaska Airlines
Find Deal
Wed, Oct 1 - Fri, Oct 17
Frontier Logo
6:45 am - 12:30 amPHL-SEA
20h 45m1 stop
Frontier Logo
6:12 am - 12:57 amSEA-PHL
15h 45m1 stop
$279Frontier
Find Deal
Fri, Sep 26 - Fri, Oct 3
Hawaiian Airlines Logo
7:22 am - 10:18 amPHL-SEA
5h 56mnonstop
Hawaiian Airlines Logo
9:45 pm - 6:02 amSEA-PHL
5h 17mnonstop
$282Hawaiian Airlines
Find Deal
Mon, Sep 15 - Tue, Sep 23
Frontier Logo
6:45 am - 8:39 pmPHL-SEA
16h 54m1 stop
Frontier Logo
6:12 am - 12:57 amSEA-PHL
15h 45m1 stop
$284Frontier
Find Deal
Sat, Sep 20 - Fri, Sep 26
United Airlines Logo
3:00 pm - 8:42 pmPHL-SEA
8h 42m1 stop
United Airlines Logo
7:00 am - 5:35 pmSEA-PHL
7h 35m1 stop
$287United Airlines
Find Deal
Tue, Sep 16 - Sat, Sep 27
United Airlines Logo
10:10 am - 5:54 pmPHL-SEA
10h 44m2 stops
United Airlines Logo
7:00 am - 5:35 pmSEA-PHL
7h 35m1 stop
$292United Airlines
Find Deal
Tue, Sep 16 - Sat, Sep 27
Delta Logo
6:25 pm - 11:54 pmPHL-SEA
8h 29m1 stop
Delta Logo
7:30 pm - 5:45 amSEA-PHL
7h 15m1 stop
$297Delta
Find Deal
Fri, Sep 26 - Mon, Sep 29
Delta Logo
6:40 pm - 12:09 amPHL-SEA
8h 29m1 stop
Delta Logo
6:10 am - 5:54 pmSEA-PHL
8h 44m1 stop
$305Delta
Find Deal
Fri, Dec 12 - Fri, Jan 2
American Airlines Logo
6:50 pm - 10:04 pmPHL-SEA
6h 14mnonstop
American Airlines Logo
7:45 am - 4:05 pmSEA-PHL
5h 20mnonstop
$307American Airlines
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Mon, Sep 22 - Sat, Sep 27
American Airlines Logo
8:09 am - 11:03 amPHL-SEA
5h 54mnonstop
American Airlines Logo
12:34 am - 12:50 pmSEA-PHL
9h 16m1 stop
$317American Airlines
Find Deal
Fri, Oct 17 - Mon, Oct 20

American Airlines flights from Philadelphia to Seattle

Our best American Airlines deals on Philadelphia to Seattle flight tickets
American Airlines
Aug 31
PHL7:10 pmPhiladelphia
6h 16m
SEA10:26 pmSeattle/Tacoma Intl
Sep 6
SEA7:45 amSeattle/Tacoma Intl
5h 20m
PHL4:05 pmPhiladelphia
$277
Find similar
American Airlines
Sep 3
PHL6:50 pmPhiladelphia
6h 14m
SEA10:04 pmSeattle/Tacoma Intl
Sep 5
SEA11:05 pmSeattle/Tacoma Intl
5h 04m
PHL7:09 amPhiladelphia
$287
Find similar
American Airlines
Sep 22
PHL6:50 pmPhiladelphia
6h 14m
SEA10:04 pmSeattle/Tacoma Intl
Sep 27
SEA7:45 amSeattle/Tacoma Intl
5h 20m
PHL4:05 pmPhiladelphia
$307
Find similar

Frontier flights from Philadelphia to Seattle

Our best Frontier deals on Philadelphia to Seattle flight tickets
Frontier
Sep 26
PHL6:45 amPhiladelphia
20h 45m
1 stop
SEA12:30 amSeattle/Tacoma Intl
Oct 3
SEA6:12 amSeattle/Tacoma Intl
15h 45m
1 stop
PHL12:57 amPhiladelphia
$279
Find similar
Frontier
Sep 6
PHL6:45 amPhiladelphia
16h 54m
1 stop
SEA8:39 pmSeattle/Tacoma Intl
Sep 14
SEA6:12 amSeattle/Tacoma Intl
15h 45m
1 stop
PHL12:57 amPhiladelphia
$283
Find similar
Frontier
Sep 20
PHL6:45 amPhiladelphia
16h 54m
1 stop
SEA8:39 pmSeattle/Tacoma Intl
Sep 26
SEA6:12 amSeattle/Tacoma Intl
15h 45m
1 stop
PHL12:57 amPhiladelphia
$284
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Philadelphia to Seattle 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, momondo users made 832,500 searches. Data last updated August 25, 2025.
Use the filters below to find and compare flights from Philadelphia to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Wed 10/1

7:22 am-10:18 am

Nonstop5h 56m

Seattle/Tacoma Intl

Fri 10/17

9:23 pm-5:40 am

Nonstop5h 17m

$277

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Fri 9/26

6:45 am-12:30 am

1 stop20h 45m

Seattle/Tacoma Intl

Fri 10/3

6:12 am-12:57 am

1 stop15h 45m

$279

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Mon 9/15

7:22 am-10:18 am

Nonstop5h 56m

Seattle/Tacoma Intl

Tue 9/23

9:45 pm-6:02 am

Nonstop5h 17m

$282

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Sat 9/20

6:45 am-8:39 pm

1 stop16h 54m

Seattle/Tacoma Intl

Fri 9/26

6:12 am-12:57 am

1 stop15h 45m

$284

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Tue 9/16

3:00 pm-8:42 pm

1 stop8h 42m

Seattle/Tacoma Intl

Sat 9/27

7:00 am-5:35 pm

1 stop7h 35m

$287

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Tue 9/16

10:10 am-5:54 pm

2 stops10h 44m

Seattle/Tacoma Intl

Sat 9/27

7:00 am-5:35 pm

1 stop7h 35m

$292

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Fri 9/26

6:25 pm-11:54 pm

1 stop8h 29m

Seattle/Tacoma Intl

Mon 9/29

7:30 pm-5:45 am

1 stop7h 15m

$297

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Fri 12/12

6:40 pm-12:09 am

1 stop8h 29m

Seattle/Tacoma Intl

Fri 1/2

6:10 am-5:54 pm

1 stop8h 44m

$305

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Mon 9/22

6:50 pm-10:04 pm

Nonstop6h 14m

Seattle/Tacoma Intl

Sat 9/27

7:45 am-4:05 pm

Nonstop5h 20m

$307

PhiladelphiaSeattle

PHL - SEA

PHLSEA

Philadelphia

Fri 10/17

8:09 am-11:03 am

Nonstop5h 54m

Seattle/Tacoma Intl

Mon 10/20

12:34 am-12:50 pm

1 stop9h 16m

$317

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Seattle from

How to get the cheapest flight ticket from Philadelphia to Seattle

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Seattle?

In general, March is the cheapest month to fly from Philadelphia to Seattle. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $367. If you don’t want to visit Seattle in March, then you should wait until January to fly from Philadelphia, when ticket prices are also cheap, with an average price of $387.

What is the cheapest day to depart on your flight to Seattle?

On average, the least expensive day to fly to Seattle from Philadelphia is on a Thursday. momondo users have found tickets for Thursday departures for as low as $478. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Sunday is the most expensive day to depart from Philadelphia because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $590.

What is the cheapest time of day to depart on your flight to Seattle?

Flying to Seattle from Philadelphia at noon is the least expensive time of day to depart. momondo users have found prices as low as $416 when looking at flights departing at noon. Flights to Seattle are more costly in the morning, with an average ticket price of $539. Departure times in the morning fall within the peak daily travel times, which is why tickets can be more expensive.

What is the cheapest Philadelphia to Seattle/Tacoma Intl flight route?

Fly from Philadelphia to Seattle/Tacoma Intl for the best Philadelphia - Seattle/Tacoma Intl flight prices

How far in advance should I book a flight to Seattle?

You are more likely to see cheaper flights to Seattle from Philadelphia when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around $429 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from Philadelphia for as low as $376 on momondo.

What cabin class options are available on Philadelphia to Seattle/Tacoma Intl flights?

There are 4 cabin classes available to choose from on Philadelphia to Seattle/Tacoma Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have Philadelphia to Seattle flight prices changed over time?

As of August 2025, prices for Philadelphia to Seattle flights are approximately 7% more expensive when compared to flights at the same time last year.

When to book flights from Philadelphia to Seattle

Are you open to changing your travel dates? Check out the ideal times to fly from Philadelphia to Seattle according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Philadelphia to Seattle (PHL to SEA) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Philadelphia to Seattle

Best Price Found

$199

Fastest flight time

5h 49m

Direct flights

Every day

Airports in Seattle

1 airport
The best one-way flight to Seattle from Philadelphia in the past 72 hours is $199. The best round-trip flight deal from Philadelphia to Seattle found on momondo in the last 72 hours is $329.
The fastest flight from Philadelphia to Seattle takes 5h 49m
Direct flights go from Philadelphia to Seattle every day.
There is 1 airport near Seattle: Seattle/Tacoma Intl (SEA)
Search flight deals

  • How far is Philadelphia to Seattle/Tacoma Intl by plane?

    The straight-line distance from Philadelphia to Seattle/Tacoma Intl is 2372.3 mi. 5h 54m is a normal flight duration for this route.

  • When did momondo last update prices for flights from Philadelphia Airport to Seattle/Tacoma Intl Airport?

    Prices for flights from Philadelphia Airport to Seattle/Tacoma Intl Airport refresh daily.

  • How many operators does momondo search for flights from Philadelphia Airport to Seattle/Tacoma Intl Airport?

  • How old do you have to be to fly from Philadelphia Airport to Seattle/Tacoma Intl Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Philadelphia Airport to Seattle/Tacoma Intl Airport.

  • What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

    The travel and health documents required for your trip to Seattle/Tacoma Intl Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Seattle/Tacoma Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular plane model from Philadelphia to Seattle?

  • What is the most popular airline from Philadelphia to Seattle?

Best airlines flying from Philadelphia to Seattle

Compare and see reviews for airlines that fly from Philadelphia to Seattle with momondo
Airline
Rating
Free Cancellation
Price
Spirit AirlinesPriceFrom $127Free CancellationRating
6.3
8,029 reviews
Search Spirit Airlines flights
FrontierPriceFrom $128Free CancellationRating
5.8
3,201 reviews
Search Frontier flights
Sun Country AirPriceFrom $238Free CancellationRating
6.9
332 reviews
Search Sun Country Air flights
DeltaPriceFrom $258Free CancellationRating
7.9
7,981 reviews
Search Delta flights
Hawaiian AirlinesPriceFrom $277Free CancellationRating
7.8
2,679 reviews
Search Hawaiian Airlines flights
United AirlinesPriceFrom $286Free CancellationRating
7.4
8,940 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $291Free CancellationRating
8.0
10,000 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $296Free CancellationRating
8.0
4,243 reviews
Search Southwest flights
American AirlinesPriceFrom $297Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights

  • Alaska Airlines Flights From Philadelphia to Seattle

    Alaska Airlines flies from Philadelphia to Seattle around 2 times per week, with 10,000 momondo users rating the airline 8.0/10. The cheapest Alaska Airlines deal from Philadelphia to Seattle in the last 72 hours was $291 (round-trip), much lower than the average airfare cost of $497 for Alaska Airlines flights on this route.

  • Hawaiian Airlines Flights From Philadelphia to Seattle

    Hawaiian Airlines (7.8/10 from 2,679 reviews) operates around 15 flights from Philadelphia to Seattle in any given week. The average Hawaiian Airlines airfare for this route is around $480, with deals from around $277 rare but found on momondo. Referenced prices are for round-trip Philadelphia to Seattle flight searches in the last 72 hours.

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Leavenworth
Tacoma
SeaTac
Ocean Shores
Olympia
Renton
Lynnwood
Kent
Marysville
Puyallup
Federal Way
Cle Elum
Tukwila
Kirkland
Centralia
Lakewood
Shoreline
Fife
Redmond
Westport

Why use momondo?

Why should I use momondo to find a flight deal from Philadelphia to Seattle?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Philadelphia to Seattle. Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from Philadelphia to Seattle with flexible booking policies on momondo?

Yes. All flights to Seattle from Philadelphia on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Philadelphia to Seattle?

momondo provides multiple filters to help you find the best flight to Seattle from Philadelphia. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

I’m not ready to book a flight from Philadelphia to Seattle right now. Can momondo alert me if prices change?

Of course. momondo tracks the price of Philadelphia to Seattle flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

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