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Cheap flights from Portsmouth to Seattle from £472

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 21/4. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
18 Dec — 25 Dec1
1 adult
1 adult, Economy, 0 bags

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 November 2025.

Round-trip from

£521

One-way from

£472

Popular in

July

Cheapest in

February

Average price

£544
Delta
  • Delta
  • 4/12-7/12
  • 3 total stops
  • 51h 56m total
  • Portsmouth to Seattle
Search Deals
British Airways
  • British Airways
  • 21/4
  • 1 total stop
  • 15h 49m total
  • Portsmouth to Seattle
Search Deals
Highest demand for flights based on searches. 11% potential increase in price (£57 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 November 2025
Search Deals

Find 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 18 November 2025.

Thu 4/1208:50SOU - SEA
1 stop35h 00mDelta
Sun 7/1215:05SEA - SOU
1 stop33h 05mDelta
Deal found 17/11£521
Mon 15/1208:40SOU - SEA
1 stop35h 10mMultiple Airlines
Mon 22/1215:05SEA - SOU
1 stop33h 05mMultiple Airlines
Deal found 17/11£742
Mon 15/1208:40SOU - SEA
2 stops46h 45mVirgin Atlantic
Mon 22/1206:00SEA - SOU
2 stops18h 10mVirgin Atlantic
Deal found 17/11£842
Mon 15/1209:30SOU - SEA
1 stop16h 50mBritish Airways
Sun 4/118:50SEA - SOU
2 stops17h 30mBritish Airways
Deal found 17/11£1,036
Wed 31/1216:05SOU - SEA
2 stops49h 04mMultiple Airlines
Wed 7/108:04SEA - SOU
2 stops23h 31mMultiple Airlines
Deal found 15/11£1,047

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 November 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

Thu 4/12

08:50-11:50

1 stop35h 00m

Seattle/Tacoma Intl

Sun 7/12

15:05-08:10

1 stop33h 05m

£521

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 15/12

08:40-11:50

1 stop35h 10m

Seattle/Tacoma Intl

Mon 22/12

15:05-08:10

1 stop33h 05m

£742

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 15/12

08:40-23:25

2 stops46h 45m

Seattle/Tacoma Intl

Mon 22/12

06:00-08:10

2 stops18h 10m

£842

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Tue 21/4

09:10-16:59

1 stop15h 49m

£472

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 23/3

16:05-12:30

2 stops27h 25m

£481

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 23/3

09:30-19:20

1 stop16h 50m

£508

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Mon 15/12

09:30-18:20

1 stop16h 50m

£779

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Tue 16/12

20:10-18:20

1 stop30h 10m

£786

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Thu 11/12

19:55-11:30

2 stops23h 35m

£811

SouthamptonSeattle

SOU - SEA

SOUSEA

Southampton Eastleigh

Fri 12/12

09:30-18:20

1 stop16h 50m

£982

Flights are sorted by cheapest return flights first.

Deals found on 17/11

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, March is the cheapest month in which you can book a flight from Portsmouth to Seattle (average of £310). Flying from Portsmouth to Seattle in August is currently the most expensive (average of £469). 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 November 2025.

It’s optimal to fly from Portsmouth to Seattle in the morning. By choosing this option you can save up to 19% on the cost of your flight, compared to a flight in the evening.

What is the cheapest day to fly from Portsmouth to Seattle?

Use this chart to determine the cheapest time to fly return from Portsmouth to Seattle. Price data was last updated on 16 December 2024.

Travellers seeking maximum savings on their Portsmouth to Seattle flight should consider departing on Wednesday mornings when fares are most often at their lowest. Sunday at midday flights should be avoided if possible as fares are typically the most expensive at this time.

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 November 2025.

The most flights from P0R to SEA are scheduled on a Tuesday (21 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (11 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 £521, Delta can have you in Seattle from Portsmouth in 35h. 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 (95%), Air France (86%), KLM( 85%).

  • What are the cheapest flights from Portsmouth to Seattle?

    Looking for the cheapest flight from Portsmouth to Seattle? While on average our users pay £1,555, our data indicates the cheapest price to be £421. The most popular route (Southampton Eastleigh - Seattle/Tacoma Intl), is priced around £521.

  • 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, March is the cheapest month in which you can book a flight from Portsmouth to Seattle (average of £310). Flying from Portsmouth to Seattle in August is currently the most expensive (average of £469). 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 November 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£350Average£499FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Air FranceCheapest£393Average£611FlexibilityNo cancel feeOn-time77%
Search Air France flights
FinnairCheapest£406Average£576FlexibilityNo cancel feeOn-time76%
Search Finnair flights
LufthansaCheapest£407Average£504FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
KLMCheapest£411Average£581FlexibilityNo cancel feeOn-time75%
Search KLM flights
United AirlinesCheapest£413Average£653FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
British AirwaysCheapest£449Average£615FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£451Average£598FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
DeltaCheapest£454Average£607FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Aer LingusCheapest£466Average£678FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus 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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