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Cheap flights from Philadelphia to Seattle from £150

PHL — SEA
29 Oct — 5 Nov1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Philadelphia to Seattle

Enter your travel dates to find the best prices.

Cheapest flights from Philadelphia to Seattle

Thu 29/1005:20 -
2 stops11h 10m
Sun 1/1100:15 -
1 stop7h 45m
Deal found 27/9£273
Wed 21/1013:20 -
2 stops12h 20m
Sat 24/1005:25 -
2 stops12h 35m
Deal found 28/9£277
Thu 19/1114:45 -
2 stops11h 05m
Mon 23/1105:30 -
1 stop10h 15m
Deal found 28/9£278
Mon 19/1017:08 -
1 stop8h 45m
Mon 26/1022:56 -
1 stop7h 56m
Deal found 27/9£281
Tue 3/1106:15 -
1 stop9h 04m
Tue 3/1119:35 -
2 stops13h 02m
Deal found 25/9£281
Fri 11/1218:25 -
1 stop9h 05m
Mon 14/1220:15 -
2 stops11h 50m
Deal found 27/9£284
Fri 23/1017:10 -
2 stops10h 50m
Mon 26/1021:15 -
2 stops10h 25m
Deal found 25/9£288
Fri 6/1113:50 -
1 stop13h 55m
Wed 11/1105:40 -
2 stops12h 45m
Deal found 25/9£289
Thu 5/1118:21 -
1 stop9h 38m
Sun 8/1122:56 -
1 stop7h 56m
Deal found 29/9£292
Tue 17/1109:45 -
1 stop8h 47m
Sat 21/1122:56 -
1 stop7h 49m
Deal found 25/9£293
Thu 29/1012:35 -
2 stops10h 30m
Sun 1/1109:10 -
1 stop7h 15m
Deal found 28/9£296
Fri 20/1118:25 -
1 stop9h 10m
Mon 23/1105:30 -
1 stop10h 15m
Deal found 28/9£297

Find flight deals from Philadelphia to Seattle

Round-trip from

£273

One-way from

£150

Popular in

August

Cheapest in

January

Average price

£306
Southwest
  • Southwest
  • 29/10-4/11
  • 3 total stops
  • 17h 35m total
  • Philadelphia to Seattle
Search Deals
Southwest
  • Southwest
  • 4/12-31/12
  • 2 total stops
  • 11h 30m total
  • Philadelphia to Seattle
Search Deals
Highest demand for flights based on searches. 9% potential increase in price (£24 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (£4 potential savings vs. average return price).
Search Deals
Average for round-trip flights in September 2026
Search Deals

Cheapflights Fare Finder

 
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

Cheapest return flight

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Mon 23/11

06:00-13:54

2 stops10h 54m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£150

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Sun 22/11

10:00-17:57

1 stop10h 57m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£158

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Sun 8/11

06:15-12:19

1 stop9h 04m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£158

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Fri 4/12

07:30-16:00

2 stops11h 30m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£158
Fastest return journey

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Thu 5/11

07:00-09:58

Nonstop5h 58m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£173

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Sun 15/11

07:00-10:05

Nonstop6h 05m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£173

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Tue 1/12

18:20-23:35

1 stop8h 15m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£173

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Wed 25/11

07:00-10:05

Nonstop6h 05m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£174

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Sat 10/10

16:15-21:45

1 stop8h 30m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£180

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Thu 26/11

06:00-16:19

2 stops13h 19m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£188

Flights are sorted by cheapest return flights first.

Deals found on 28/9

Showing 1-10 of 23 resultsSorted by cheapest first
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Best time to book a flight from Philadelphia to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Philadelphia with our price prediction graph.
Estimated return price

Cheapflights Insights

Everything you need to know about your flight from Philadelphia to Seattle

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

Booking 70 days in advance of your planned departure date is, on average, the best time to get cheap flights from Philadelphia to Seattle. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, January is the cheapest month in which you can book a flight from Philadelphia to Seattle (average of £254). Flying from Philadelphia to Seattle in August is currently the most expensive (average of £355). 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 PHL to SEA?

When flying from Philadelphia to Seattle, 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 for a return flight from Philadelphia to Seattle?

Airfare is typical for this route at the moment.

Philadelphia to Seattle flights typically cost between £256 and £363 in October.
The cheapest return price found within the last 5 days was £273 on Southwest (29 Oct–4 Nov).

Related info for your journey

  • How popular is this Philadelphia to Seattle flight route?

    Within the past month, 1 users have taken a look at flights from Philadelphia to Seattle/Tacoma Intl.

  • How long is the flight from Philadelphia to Seattle?

    For as low as £300, United Airlines can have you in Seattle from Philadelphia in 6h 06m. Philadelphia and Seattle are separated by a distance of 2370 mi. Both multi-stop and direct flights can be found to your destination and back.

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

    Before booking your flight to Seattle from Philadelphia, check out the most reliable airlines to get you to your destination on time: Finnair (83%), Alaska Airlines (67%), Delta( 62%).

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Philadelphia to Seattle 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 Philadelphia to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Philadelphia to Seattle (average of £254). Flying from Philadelphia to Seattle in August is currently the most expensive (average of £355). 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 Seattle?

Book flights to Seattle if you plan to visit one of these locations
Federal Way
SeaTac

Browse thousands of different options on Cheapflights for your next trip

Alternative routes for Philadelphia to Seattle

Dulles Intl to Seattle flights
Newark to Seattle flights
John F Kennedy Intl to Seattle flights
John F Kennedy Intl to Portland flights

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How does Cheapflights help users find flights from Philadelphia to Seattle?

Deals for Philadelphia to Seattle flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Philadelphia to Seattle?

Cheapflights helps you find that perfect flight to Seattle from Philadelphia by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Philadelphia to Seattle with no change fees?

Need flexible booking options for your flight to Seattle from Philadelphia? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

Can Cheapflights notify me if prices for flights from Philadelphia to Seattle become cheaper?

Yes! Start tracking prices for Philadelphia to Seattle flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

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