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Cheap flights from Portsmouth to Seattle from £541

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 4/3. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
18 Oct — 25 Oct1
1 adult
1 adult, Economy

Cheap flight deals from Portsmouth to Seattle

Keep the following information in mind while searching for Portsmouth to Seattle flight deals. Data was last updated 18 September 2025.

Round-trip from

£541

Popular in

July

Cheapest in

January

Average price

£496
Delta
  • Delta
  • 4/3-8/3
  • 3 total stops
  • 69h 50m total
  • Portsmouth to Seattle
Search Deals
Highest demand for flights based on searches. 13% potential increase in price (£61 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (£10 potential savings vs. average return price).
Search Deals
Average for round-trip flights in September 2025
Search Deals

Find flight deals from Portsmouth to Seattle

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 18 September 2025.

Wed 24/909:20SOU - SEA
1 stop14h 45mDelta
Mon 24/1115:00SEA - SOU
1 stop18h 00mDelta
Deal found 17/9£573
Thu 25/909:20SOU - SEA
1 stop14h 45mDelta
Wed 26/1122:14SEA - SOU
2 stops25h 51mDelta
Deal found 17/9£579
Wed 24/909:20SOU - SEA
2 stops18h 48mDelta
Wed 26/1107:20SEA - SOU
2 stops17h 00mDelta
Deal found 17/9£582
Wed 24/909:20SOU - SEA
1 stop14h 45mDelta
Sat 29/1115:00SEA - SOU
1 stop33h 10mDelta
Deal found 17/9£603
Thu 25/909:20SOU - SEA
1 stop14h 45mDelta
Fri 28/1115:00SEA - SOU
1 stop18h 00mDelta
Deal found 17/9£609
Sat 27/909:20SOU - SEA
2 stops18h 55mMultiple Airlines
Thu 27/1106:00SEA - SOU
2 stops18h 05mMultiple Airlines
Deal found 17/9£652
Sat 27/909:40SOU - SEA
1 stop16h 10mBritish Airways
Mon 24/1120:05SEA - SOU
1 stop15h 35mBritish Airways
Deal found 17/9£797
Fri 26/920:00SOU - SEA
1 stop29h 50mBritish Airways
Wed 26/1120:05SEA - SOU
1 stop15h 35mBritish Airways
Deal found 17/9£805
Sat 27/909:40SOU - SEA
1 stop16h 10mBritish Airways
Sun 30/1120:05SEA - SOU
1 stop15h 35mBritish Airways
Deal found 17/9£827
Sat 27/909:40SOU - SEA
1 stop16h 10mBritish Airways
Fri 28/1120:05SEA - SOU
1 stop28h 40mBritish Airways
Deal found 17/9£833
Fri 26/920:00SOU - SEA
1 stop29h 50mBritish Airways
Sun 30/1120:05SEA - SOU
1 stop15h 35mBritish Airways
Deal found 17/9£835
Mon 29/917:35SOU - SEA
1 stop30h 30mDelta
Wed 26/1115:00SEA - SOU
1 stop18h 25mDelta
Deal found 17/9£840

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 18 September 2025.
Use the filters below to find and compare flights from Portsmouth to Seattle that are best for you.

Fly from

Portsmouth

Fly to

Seattle

Route

Depart

Return

Price

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Wed 4/3

08:40-11:35

1 stop34h 55m

Seattle/Tacoma Intl

Sun 8/3

23:05-17:00

2 stops34h 55m

£541

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Wed 4/3

08:40-22:16

2 stops21h 36m

Seattle/Tacoma Intl

Sun 8/3

22:00-17:00

2 stops36h 00m

£545

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Sun 28/9

18:25-21:00

2 stops34h 35m

Seattle/Tacoma Intl

Tue 25/11

15:00-17:00

1 stop18h 00m

£573

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Sun 28/9

18:25-11:45

1 stop25h 20m

Seattle/Tacoma Intl

Wed 26/11

15:00-08:05

1 stop33h 05m

£573

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Tue 30/9

09:20-11:50

1 stop34h 30m

Seattle/Tacoma Intl

Wed 26/11

22:14-08:05

2 stops25h 51m

£573

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Sun 28/9

18:25-11:45

1 stop25h 20m

Seattle/Tacoma Intl

Thu 27/11

15:00-17:00

1 stop18h 00m

£573

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Tue 30/9

17:35-11:50

1 stop26h 15m

Seattle/Tacoma Intl

Mon 24/11

15:00-17:00

1 stop18h 00m

£573

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Sun 28/9

18:25-11:45

1 stop25h 20m

Seattle/Tacoma Intl

Mon 24/11

07:20-17:00

2 stops25h 40m

£573

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Tue 30/9

17:35-11:50

1 stop26h 15m

Seattle/Tacoma Intl

Thu 27/11

07:20-08:05

2 stops16h 45m

£573

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Sun 4/1

20:00-11:30

2 stops47h 30m

£580

Flights are sorted by cheapest return flights first.

Deals found on 16/9

Showing 1-10 of 13 results
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 £622). Flying from Portsmouth to Seattle in July is currently the most expensive (average of £946). 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 18 September 2025.

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 18 September 2025.

The most flights from P0R to SEA are scheduled on a Monday (21 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (10 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. 14 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 £545, Delta can have you in Seattle from Portsmouth in 21h 36m. 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 (95%), KLM (93%), Air France( 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 £1,560, our data indicates the cheapest price to be £435. The most popular route (Southampton Eastleigh - Seattle/Tacoma Intl), is priced around £541.

  • 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 £622). Flying from Portsmouth to Seattle in July is currently the most expensive (average of £946). 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
Leavenworth
Bothell
SeaTac

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Alternative routes for Portsmouth to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
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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 18 September 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£320Average£490FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Air FranceCheapest£378Average£566FlexibilityNo cancel feeOn-time77%
Search Air France flights
LufthansaCheapest£389Average£485FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
FinnairCheapest£390Average£534FlexibilityNo cancel feeOn-time76%
Search Finnair flights
KLMCheapest£398Average£558FlexibilityNo cancel feeOn-time75%
Search KLM flights
United AirlinesCheapest£399Average£635FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Aer LingusCheapest£400Average£652FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
British AirwaysCheapest£421Average£586FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£432Average£524FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
DeltaCheapest£437Average£586FlexibilityNo cancel feeOn-timeN/A
Search Delta flights

Fly with Cheapflights

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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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