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Cheap flights from Portsmouth to Seattle from £519

LHR — SEA
18 Sep — 25 Sep1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Portsmouth to Seattle

Enter your travel dates to find the best prices.

Cheapest flights from Portsmouth to Seattle

Tue 29/909:05 -
1 stop15h 30m
Tue 6/1013:45 -
1 stop34h 50m
Deal found 15/8£655
Thu 1/1017:20 -
1 stop31h 15m
Thu 8/1013:45 -
1 stop35h 00m
Deal found 17/8£655
Thu 1/1009:05 -
2 stops22h 50m
Thu 8/1017:45 -
1 stop15h 05m
Deal found 17/8£675
Sat 3/1017:20 -
1 stop31h 15m
Sat 10/1017:45 -
1 stop15h 05m
Deal found 19/8£684
Sat 3/1009:15 -
2 stops20h 48m
Sat 10/1007:45 -
2 stops17h 00m
Deal found 19/8£689
Fri 2/1009:20 -
1 stop15h 50m
Fri 9/1019:10 -
1 stop13h 40m
Deal found 18/8£700
Fri 2/1009:05 -
1 stop15h 30m
Fri 9/1022:59 -
2 stops25h 46m
Deal found 18/8£726
Wed 30/909:20 -
1 stop15h 50m
Sun 4/1019:10 -
1 stop16h 20m
Deal found 14/8£797

Find flight deals from Portsmouth to Seattle

Round-trip from

£655

One-way from

£519

Popular in

August

Cheapest in

February

Average price

£631
KLM
  • KLM
  • 29/9-6/10
  • 2 total stops
  • 50h 20m total
  • Portsmouth to Seattle
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British Airways
  • British Airways
  • 28/12
  • 2 total stops
  • 36h 35m total
  • Portsmouth to Seattle
Search Deals
Highest demand for flights based on searches. 6% potential increase in price (£26 potential increase over avg. return price).
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Cheapest flight prices on average. 1% potential price decrease (£5 potential savings vs. average return price).
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Average for round-trip flights in August 2026
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Cheapflights Fare Finder

 
Use the filters below to find and compare flights from Portsmouth to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Tue 29/9

09:05-11:47

1 stop34h 42m

Seattle/Tacoma Intl

Tue 6/10

09:36-08:45

2 stops15h 09m

£657

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Thu 1/10

09:05-23:55

2 stops22h 50m

Seattle/Tacoma Intl

Thu 8/10

17:45-16:50

1 stop15h 05m

£675

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Sat 3/10

17:20-16:35

1 stop31h 15m

Seattle/Tacoma Intl

Sat 10/10

07:45-08:45

2 stops17h 00m

£684

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Sat 3/10

09:15-22:03

2 stops20h 48m

Seattle/Tacoma Intl

Sat 10/10

07:45-08:45

2 stops17h 00m

£689
Fastest return journey

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Fri 2/10

09:20-17:10

1 stop15h 50m

Seattle/Tacoma Intl

Fri 9/10

19:10-16:50

1 stop13h 40m

£700

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Wed 30/9

09:20-17:10

1 stop15h 50m

Seattle/Tacoma Intl

Sun 4/10

19:10-19:30

1 stop16h 20m

£797
Cheapest one-way

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Sat 26/12

19:55-16:50

2 stops28h 55m

£519

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Sun 27/12

20:50-16:50

2 stops28h 00m

£519

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Thu 17/9

17:20-17:10

1 stop31h 50m

£817

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Wed 30/12

06:50-16:50

2 stops42h 00m

£837

Flights are sorted by cheapest return flights first.

Deals found on 18/8

Showing 1-10 of 17 resultsSorted by cheapest first
1
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Best time to book a flight from Portsmouth to Seattle

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

Cheapflights Insights

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

What is the cheapest time of day to fly from P0R to SEA?

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

Weekly flight availability from Portsmouth to Seattle

The most flights from P0R to SEA are scheduled on a Tuesday (24 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (12 on average).

Related info for your journey

  • What airport do you fly into for flights to Seattle from Portsmouth?

    For a flight from Portsmouth to Seattle, you will be flying into Seattle/Tacoma Intl. Seattle/Tacoma Intl (SEA) is just 11.4 mi from the center of the city. Seattle/Tacoma Intl is the only Seattle airport and it handles 0 inbound flights from Portsmouth per day. 12 airlines have flights to Seattle/Tacoma Intl from Portsmouth on a regular basis.

  • How long is the flight from Portsmouth to Seattle?

    For as low as £655, KLM can have you in Seattle from Portsmouth in 15h 30m. The distance from Portsmouth to Seattle is about 4787 mi. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

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

    Before booking your flight to Seattle from Portsmouth, check out the most reliable airlines to get you to your destination on time: Scandinavian Airlines (82%), American Airlines (75%), KLM( 75%).

  • What are the cheapest flights from Portsmouth to Seattle?

    Looking for the cheapest flight from Portsmouth to Seattle? While on average our users pay £1,218, our data indicates the cheapest price to be £323. The most popular route (Southampton Eastleigh - Seattle/Tacoma Intl), is priced around £655.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Portsmouth 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.

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

Top 10 airlines flying from Portsmouth to Seattle

AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£332Average£420FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
IcelandairCheapest£338Average£500FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Aer LingusCheapest£388Average£628FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
United AirlinesCheapest£414Average£485FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Virgin AtlanticCheapest£419Average£586FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
KLMCheapest£430Average£607FlexibilityNo cancel feeOn-time75%
Search KLM flights
DeltaCheapest£437Average£644FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air FranceCheapest£446Average£619FlexibilityNo cancel feeOn-time77%
Search Air France flights
British AirwaysCheapest£450Average£628FlexibilityNo cancel feeOn-time70%
Search British Airways flights
FinnairCheapest£457Average£670FlexibilityNo cancel feeOn-time76%
Search Finnair flights

Fly with Cheapflights

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

900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Seattle from Portsmouth today with Cheapflights!

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

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Portsmouth to Seattle for you. Better yet — we are completely free to use.

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

Yes, we can. To see specific flights from Portsmouth to Seattle with no change fees, users can toggle flexible booking options after using the search form above to find flights.

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

Yes, Cheapflights has a feature called Price Alert, which notifies users when flight prices change. Track prices for your flight to Seattle from Portsmouth today and book when prices fit your budget.

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