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Cheap flights from Portsmouth to Seattle from £524

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 23/3. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
6 Apr — 13 Apr1
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 March 2026.

Mon 20/417:20
SOU
-
SEA
2 stops29h 22m
KLM
Mon 27/422:40
SEA
-
SOU
2 stops49h 55m
KLM
Deal found 6/3£679
Mon 20/417:20
SOU
-
SEA
1 stop31h 50m
Aer Lingus
Mon 27/419:10
SEA
-
SOU
1 stop16h 20m
Aer Lingus
Deal found 6/3£690
Fri 25/908:55
SOU
-
SEA
2 stops34h 40m
British Airways
Mon 28/919:10
SEA
-
SOU
1 stop16h 20m
British Airways
Deal found 5/3£786
Sat 4/417:20
SOU
-
SEA
1 stop31h 10m
KLM
Sat 11/413:45
SEA
-
SOU
1 stop34h 50m
KLM
Deal found 7/3£931

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 March 2026.

Round-trip from

£679

One-way from

£524

Popular in

July

Cheapest in

February

Average price

£539
KLM
  • KLM
  • 20/4-27/4
  • 4 total stops
  • 79h 17m total
  • Portsmouth to Seattle
Search Deals
Aer Lingus
  • Aer Lingus
  • 23/3
  • 1 total stop
  • 16h 50m total
  • Portsmouth to Seattle
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (£56 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (£9 potential savings vs. average return price).
Search Deals
Average for round-trip flights in March 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 March 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 - SEA

SOUSEA

Southampton Eastleigh

Mon 20/4

17:20-14:42

2 stops29h 22m

Seattle/Tacoma Intl

Mon 27/4

22:40-08:35

2 stops49h 55m

£679

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 20/4

17:20-17:10

1 stop31h 50m

Seattle/Tacoma Intl

Mon 27/4

19:10-19:30

1 stop16h 20m

£690

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Sat 4/4

17:20-16:30

1 stop31h 10m

Seattle/Tacoma Intl

Sat 11/4

13:45-08:35

1 stop34h 50m

£931

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 20/4

17:20-11:35

2 stops26h 15m

Seattle/Tacoma Intl

Mon 27/4

13:35-08:35

3 stops35h 00m

£953

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Sat 4/4

09:20-22:53

3 stops45h 33m

Seattle/Tacoma Intl

Sat 11/4

14:10-16:50

2 stops18h 40m

£1,405
Fastest return journey

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Wed 15/4

09:10-17:10

1 stop16h 00m

Seattle/Tacoma Intl

Wed 15/4

19:10-16:50

1 stop13h 40m

£3,226
Cheapest one-way

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Tue 30/6

14:25-17:10

2 stops34h 45m

£530

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Sun 28/6

14:45-17:10

2 stops34h 25m

£530

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Wed 1/7

06:50-17:10

2 stops18h 20m

£545

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 23/3

16:05-23:04

2 stops37h 59m

£556

Flights are sorted by cheapest return flights first.

Deals found on 4/3

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
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 month to book a flight from Portsmouth to Seattle?

Currently, January is the cheapest month in which you can book a flight from Portsmouth to Seattle (average of £350). Flying from Portsmouth to Seattle in August is currently the most expensive (average of £467). 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 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 March 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.

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. 15 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 £679, KLM can have you in Seattle from Portsmouth in 29h 22m. 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: KLM (93%), Air France (93%), Delta( 93%).

  • What are the cheapest flights from Portsmouth to Seattle?

    Looking for the cheapest flight from Portsmouth to Seattle? While on average our users pay £1,734, our data indicates the cheapest price to be £408. The most popular route (Southampton Eastleigh - Seattle/Tacoma Intl), is priced around £679.

  • 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.

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

    Currently, January is the cheapest month in which you can book a flight from Portsmouth to Seattle (average of £350). Flying from Portsmouth to Seattle in August is currently the most expensive (average of £467). 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
Tacoma
Federal Way
SeaTac

Browse thousands of different options on Cheapflights for your next trip

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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 March 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£337Average£488FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
IcelandairCheapest£342Average£473FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
IberiaCheapest£408Average£627FlexibilityNo cancel feeOn-time77%
Search Iberia flights
Aer LingusCheapest£419Average£678FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
United AirlinesCheapest£424Average£659FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Virgin AtlanticCheapest£429Average£584FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
KLMCheapest£443Average£593FlexibilityNo cancel feeOn-time75%
Search KLM flights
British AirwaysCheapest£450Average£623FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Air FranceCheapest£452Average£641FlexibilityNo cancel feeOn-time77%
Search Air France flights
FinnairCheapest£463Average£637FlexibilityNo cancel feeOn-time76%
Search Finnair 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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