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Cheap flights from Portsmouth to Seattle from £508

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 4/11. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
6 Sep — 13 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
Explore the most affordable flight options available from Portsmouth to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 7 August 2026.

Tue 15/909:05 -
1 stop15h 30m
Tue 22/917:45 -
1 stop15h 05m
Deal found 4/8£650
Tue 15/909:05 -
1 stop15h 30m
Tue 22/911:50 -
2 stops21h 00m
Deal found 4/8£671
Sat 19/909:15 -
2 stops22h 05m
Sat 17/1017:45 -
1 stop15h 05m
Deal found 3/8£677
Mon 31/809:05 -
2 stops20h 55m
Mon 7/917:45 -
1 stop15h 05m
Deal found 3/8£692
Mon 31/809:05 -
2 stops20h 55m
Mon 7/917:45 -
1 stop15h 05m
Deal found 3/8£698
Thu 17/909:05 -
1 stop15h 30m
Thu 24/917:45 -
1 stop15h 05m
Deal found 3/8£716

Find flight deals from Portsmouth to Seattle

Keep the following information in mind while searching for Portsmouth to Seattle flight deals. Data was last updated 7 August 2026.

Round-trip from

£650

One-way from

£508

Popular in

December

Cheapest in

February

Average price

£609
KLM
  • KLM
  • 15/9-22/9
  • 2 total stops
  • 30h 35m total
  • Portsmouth to Seattle
Search Deals
British Airways
  • British Airways
  • 4/11
  • 2 total stops
  • 28h 10m total
  • Portsmouth to Seattle
Search Deals
High demand for flights, 1% potential price rise
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

 
Customise your flight search to find flights from Portsmouth 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, Cheapflights users made 858,174 searches. Data last updated 7 August 2026.
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 15/9

09:05-16:35

1 stop15h 30m

Seattle/Tacoma Intl

Tue 22/9

17:45-16:50

1 stop15h 05m

£650

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Tue 15/9

09:05-16:35

1 stop15h 30m

Seattle/Tacoma Intl

Tue 22/9

13:50-16:50

1 stop19h 00m

£671

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Sat 19/9

09:15-23:20

2 stops22h 05m

Seattle/Tacoma Intl

Sat 17/10

17:45-16:50

1 stop15h 05m

£677

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Thu 17/9

09:05-23:20

2 stops22h 15m

Seattle/Tacoma Intl

Thu 24/9

17:45-16:50

1 stop15h 05m

£724
Fastest return journey

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Mon 31/8

09:05-16:27

1 stop15h 22m

Seattle/Tacoma Intl

Mon 7/9

17:45-16:50

1 stop15h 05m

£741

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Tue 13/10

09:15-17:10

1 stop15h 55m

Seattle/Tacoma Intl

Wed 21/10

19:10-19:30

1 stop16h 20m

£767

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Thu 17/9

09:05-20:21

2 stops19h 16m

Seattle/Tacoma Intl

Thu 24/9

06:00-08:35

2 stops18h 35m

£771

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Wed 30/9

20:00-17:10

1 stop29h 10m

Seattle/Tacoma Intl

Wed 14/10

19:10-19:30

1 stop16h 20m

£780
Cheapest one-way

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Sat 7/11

07:50-16:50

2 stops41h 00m

£517
Fastest single journey

SouthamptonSeattle

SOU Southampton Eastleigh - SEA Seattle/Tacoma Intl

SOUSEA

Southampton Eastleigh

Thu 5/11

06:50-16:50

2 stops18h 00m

£517

Flights are sorted by cheapest return flights first.

Deals found on 4/8

Showing 1-10 of 13 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
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 Portsmouth to Seattle

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

Find hourly flight availability from Portsmouth to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 7 August 2026.

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

Explore weekly flight availability from Portsmouth to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 7 August 2026.

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 (18 on average).

Related info for your journey

Find useful and relevant information for your journey from Portsmouth to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • 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. 13 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 £650, KLM can have you in Seattle from Portsmouth in 15h 30m. The distance from Portsmouth to Seattle is about 4787 mi.

  • 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 (85%), KLM (77%), Air France( 77%).

  • What are the cheapest flights from Portsmouth to Seattle?

    Looking for the cheapest flight from Portsmouth to Seattle? While on average our users pay £1,818, our data indicates the cheapest price to be £379. The most popular route (Southampton Eastleigh - Seattle/Tacoma Intl), is priced around £654.

  • 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

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Top 10 airlines flying from Portsmouth to Seattle

Discover the top 10 airlines that operate flights from Portsmouth to Seattle. 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 858,174 searches. Data last updated 7 August 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£333Average£513FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
IcelandairCheapest£340Average£500FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Aer LingusCheapest£390Average£618FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
Virgin AtlanticCheapest£422Average£585FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
United AirlinesCheapest£429Average£638FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
KLMCheapest£432Average£610FlexibilityNo cancel feeOn-time75%
Search KLM flights
DeltaCheapest£440Average£636FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air FranceCheapest£449Average£634FlexibilityNo cancel feeOn-time77%
Search Air France flights
FinnairCheapest£460Average£669FlexibilityNo cancel feeOn-time76%
Search Finnair flights
British AirwaysCheapest£461Average£642FlexibilityNo cancel feeOn-time70%
Search British Airways flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

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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