Find flights
When to book
FAQs

Cheap flights from Portsmouth to Seattle from £603

LHR — SEA
22 Sep — 29 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

Mon 5/1009:20 -
1 stop15h 50m
Mon 12/1019:10 -
1 stop16h 20m
Deal found 22/8£603
Mon 5/1020:00 -
2 stops46h 35m
Mon 12/1019:10 -
1 stop16h 20m
Deal found 21/8£657
Mon 5/1009:05 -
2 stops19h 16m
Mon 12/1013:45 -
1 stop19h 05m
Deal found 22/8£670
Sat 3/1017:20 -
1 stop31h 15m
Sat 10/1007:45 -
2 stops17h 00m
Deal found 19/8£679
Sat 3/1009:15 -
2 stops20h 48m
Sat 10/1007:45 -
2 stops17h 00m
Deal found 19/8£683
Mon 5/1009:05 -
2 stops19h 45m
Mon 12/1010:37 -
2 stops22h 13m
Deal found 21/8£684
Wed 16/909:15 -
1 stop15h 20m
Sun 27/907:15 -
2 stops17h 20m
Deal found 20/8£713
Thu 31/1208:40 -
2 stops21h 25m
Wed 3/214:20 -
1 stop18h 40m
Deal found 21/8£717
Fri 11/917:20 -
1 stop26h 27m
Sun 27/907:15 -
2 stops17h 20m
Deal found 20/8£754
Mon 5/1009:20 -
1 stop15h 50m
Wed 21/1019:10 -
1 stop13h 40m
Deal found 19/8£761

Find flight deals from Portsmouth to Seattle

Round-trip from

£603

Popular in

August

Cheapest in

February

Average price

£628
Aer Lingus
  • Aer Lingus
  • 5/10-12/10
  • 2 total stops
  • 32h 10m 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).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (£6 potential savings vs. average return price).
Search Deals
Average for round-trip flights in August 2026
Search Deals

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

Mon 5/10

09:05-20:21

2 stops19h 16m

Seattle/Tacoma Intl

Mon 12/10

13:45-16:50

1 stop19h 05m

£670

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

£683

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Thu 31/12

08:40-22:05

2 stops21h 25m

Seattle/Tacoma Intl

Thu 28/1

08:25-08:10

2 stops15h 45m

£717

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Tue 5/1

17:30-11:50

1 stop26h 20m

Seattle/Tacoma Intl

Thu 28/1

14:25-17:00

1 stop18h 35m

£720

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Tue 12/1

17:30-11:50

1 stop26h 20m

Seattle/Tacoma Intl

Wed 10/2

14:20-17:00

1 stop18h 40m

£720

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Sat 12/9

09:15-16:35

1 stop15h 20m

Seattle/Tacoma Intl

Fri 25/9

17:45-16:50

1 stop15h 05m

£754

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Tue 6/10

09:15-17:10

1 stop15h 55m

Seattle/Tacoma Intl

Wed 21/10

19:10-16:50

1 stop13h 40m

£761
Fastest return journey

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Mon 5/10

09:20-17:10

1 stop15h 50m

Seattle/Tacoma Intl

Wed 21/10

19:10-16:50

1 stop13h 40m

£761

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Wed 14/10

09:20-17:10

1 stop15h 50m

Seattle/Tacoma Intl

Sun 18/10

19:10-16:50

1 stop13h 40m

£797
Cheapest one-way

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Tue 15/9

19:55-11:35

2 stops23h 40m

£818

Flights are sorted by cheapest return flights first.

Deals found on 18/8

Showing 1-10 of 15 resultsSorted by cheapest first
1
2

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 (13 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 £670, KLM can have you in Seattle from Portsmouth in 19h 16m. 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 £1,412, our data indicates the cheapest price to be £311. The most popular route (Southampton Eastleigh - Seattle/Tacoma Intl), is priced around £657.

  • 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£329Average£366FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
IcelandairCheapest£335Average£500FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Aer LingusCheapest£385Average£624FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
United AirlinesCheapest£410Average£481FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Virgin AtlanticCheapest£416Average£583FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
KLMCheapest£426Average£603FlexibilityNo cancel feeOn-time75%
Search KLM flights
DeltaCheapest£434Average£639FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air FranceCheapest£443Average£612FlexibilityNo cancel feeOn-time77%
Search Air France flights
British AirwaysCheapest£446Average£622FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Alaska AirlinesCheapest£463Average£594FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines 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.

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.