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Cheap flights from Portsmouth to Seattle from £522

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 15/5. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
27 Apr — 4 May1
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 28 March 2026.

Mon 11/509:05
SOU
-
SEA
1 stop34h 37m
KLM
Mon 18/517:40
SEA
-
SOU
1 stop30h 55m
KLM
Deal found 26/3£648
Mon 11/509:05
SOU
-
SEA
2 stops19h 25m
Multiple Airlines
Mon 18/513:45
SEA
-
SOU
1 stop19h 05m
Multiple Airlines
Deal found 26/3£662
Sun 10/509:20
SOU
-
SEA
1 stop15h 50m
Aer Lingus
Sun 17/519:10
SEA
-
SOU
1 stop13h 40m
Aer Lingus
Deal found 26/3£691
Sun 12/417:20
SOU
-
SEA
1 stop26h 25m
Delta
Sun 19/423:14
SEA
-
SOU
2 stops25h 21m
Delta
Deal found 26/3£727
Sat 9/517:20
SOU
-
SEA
1 stop26h 22m
KLM
Sat 16/517:40
SEA
-
SOU
1 stop15h 10m
KLM
Deal found 25/3£756
Sat 11/409:15
SOU
-
SEA
1 stop34h 30m
Delta
Sun 19/423:59
SEA
-
SOU
2 stops24h 36m
Delta
Deal found 26/3£758
Sun 12/417:20
SOU
-
SEA
2 stops31h 28m
Delta
Sat 18/423:11
SEA
-
SOU
2 stops25h 24m
Delta
Deal found 26/3£761
Sat 9/509:15
SOU
-
SEA
2 stops19h 15m
Multiple Airlines
Sat 16/517:40
SEA
-
SOU
1 stop30h 55m
Multiple Airlines
Deal found 25/3£783
Sat 9/509:15
SOU
-
SEA
2 stops20h 25m
Delta
Sat 16/506:00
SEA
-
SOU
2 stops18h 45m
Delta
Deal found 25/3£785
Thu 16/417:20
SOU
-
SEA
1 stop31h 10m
Delta
Sat 18/423:11
SEA
-
SOU
2 stops25h 24m
Delta
Deal found 26/3£788

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 28 March 2026.

Round-trip from

£648

One-way from

£522

Popular in

July

Cheapest in

February

Average price

£543
KLM
  • KLM
  • 11/5-18/5
  • 2 total stops
  • 65h 32m total
  • Portsmouth to Seattle
Search Deals
British Airways
  • British Airways
  • 15/5
  • 1 total stop
  • 15h 50m total
  • Portsmouth to Seattle
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (£57 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 28 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 11/5

09:05-11:42

1 stop34h 37m

Seattle/Tacoma Intl

Mon 18/5

17:40-08:35

1 stop30h 55m

£648

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 11/5

09:05-20:30

2 stops19h 25m

Seattle/Tacoma Intl

Mon 18/5

13:55-16:50

2 stops18h 55m

£698

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Sat 9/5

09:15-21:40

2 stops20h 25m

Seattle/Tacoma Intl

Sat 16/5

06:00-08:45

2 stops18h 45m

£785
Fastest return journey

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Wed 23/9

09:20-17:10

1 stop15h 50m

Seattle/Tacoma Intl

Sun 27/9

19:10-19:30

1 stop16h 20m

£791

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Tue 2/6

09:05-16:24

1 stop15h 19m

Seattle/Tacoma Intl

Thu 9/7

17:40-08:45

1 stop31h 05m

£806

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 1/6

17:20-11:37

1 stop26h 17m

Seattle/Tacoma Intl

Mon 13/7

17:40-17:35

1 stop15h 55m

£806

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Thu 7/5

20:00-17:10

1 stop29h 10m

Seattle/Tacoma Intl

Mon 11/5

19:10-08:05

1 stop28h 55m

£808
Cheapest one-way
Fastest single journey

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Fri 15/5

09:20-17:10

1 stop15h 50m

£522

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 25/5

09:20-17:10

1 stop15h 50m

£528

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 18/5

09:20-17:10

1 stop15h 50m

£543

Flights are sorted by cheapest return flights first.

Deals found on 26/3

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 £352). Flying from Portsmouth to Seattle in August is currently the most expensive (average of £470). 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 28 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 £791, KLM can have you in Seattle from Portsmouth in 15h 50m. 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 (98%), Air France (98%), Delta( 98%).

  • What are the cheapest flights from Portsmouth to Seattle?

    Looking for the cheapest flight from Portsmouth to Seattle? While on average our users pay £1,799, our data indicates the cheapest price to be £418. The most popular route (Southampton Eastleigh - Seattle/Tacoma Intl), is priced around £648.

  • 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 £352). Flying from Portsmouth to Seattle in August is currently the most expensive (average of £470). 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 28 March 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£337Average£497FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
IcelandairCheapest£344Average£477FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
IberiaCheapest£410Average£657FlexibilityNo cancel feeOn-time77%
Search Iberia flights
Aer LingusCheapest£421Average£678FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
Virgin AtlanticCheapest£431Average£593FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
United AirlinesCheapest£434Average£675FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
KLMCheapest£446Average£620FlexibilityNo cancel feeOn-time75%
Search KLM flights
British AirwaysCheapest£453Average£634FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Air FranceCheapest£454Average£644FlexibilityNo cancel feeOn-time77%
Search Air France flights
FinnairCheapest£465Average£650FlexibilityNo 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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