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Cheap flights from London to Seattle from £398

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 3/6. Fares are subject to change and may not be available on all flights or dates of travel.
LON — SEA
9 Jan — 16 Jan1
1 adult
1 adult, Economy, 0 bags

Cheapflights Tip: The best prices from London to Seattle/Tacoma Intl are usually found in January or February, booked 90 days in advance, depart on a Wednesday or Thursday and return on a Tuesday

Cheap flight deals from London to Seattle

Enter your travel dates to find the best prices.

Cheapest flights from London to Seattle
Explore the most affordable flight options available from London to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 10 December 2025.

Sat 27/1214:30LHR - SEA
1 stop12h 46mAir Canada
Thu 22/108:10SEA - LHR
1 stop16h 20mAir Canada
Deal found 9/12£480
Tue 23/1220:35LHR - SEA
1 stop28h 25mIcelandair
Tue 6/114:35SEA - LHR
1 stop20h 55mIcelandair
Deal found 7/12£483
Tue 23/1220:35LHR - SEA
1 stop28h 25mIcelandair
Wed 7/114:35SEA - LHR
1 stop20h 55mIcelandair
Deal found 7/12£484
Fri 26/1209:25LHR - SEA
Nonstop10h 05mBritish Airways
Fri 23/118:50SEA - LHR
Nonstop9h 30mBritish Airways
Deal found 9/12£498
Sat 27/1214:30LHR - SEA
1 stop12h 46mAir Canada
Sat 24/115:40SEA - LHR
1 stop12h 10mAir Canada
Deal found 9/12£498
Tue 9/1220:35LHR - SEA
1 stop28h 25mIcelandair
Sat 31/114:35SEA - LHR
1 stop12h 15mIcelandair
Deal found 9/12£521
Mon 8/1220:35LHR - SEA
1 stop28h 25mIcelandair
Sat 31/114:35SEA - LHR
1 stop12h 15mIcelandair
Deal found 8/12£522
Thu 11/1211:55LGW - SEA
1 stop13h 05mIcelandair
Tue 6/114:35SEA - LGW
1 stop12h 20mIcelandair
Deal found 9/12£527
Wed 24/1211:55LGW - SEA
1 stop13h 05mIcelandair
Sun 28/1214:35SEA - LGW
1 stop12h 20mIcelandair
Deal found 8/12£529
Sat 27/1209:25LHR - SEA
Nonstop10h 05mBritish Airways
Mon 19/118:50SEA - LHR
Nonstop9h 30mBritish Airways
Deal found 9/12£538
Fri 26/1211:55LGW - SEA
1 stop13h 05mIcelandair
Tue 20/114:35SEA - LGW
1 stop12h 20mIcelandair
Deal found 9/12£539
Fri 26/1211:55LGW - SEA
1 stop13h 05mIcelandair
Fri 23/114:35SEA - LGW
1 stop12h 20mIcelandair
Deal found 9/12£540

Find flight deals from London to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from London (LON) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 10 December 2025.

Round-trip from

£467

One-way from

£398

Popular in

July

Cheapest in

January

Average price

£640

Good round-trip deal

£520 or less

Good one-way deal

£464 or less
Icelandair
  • Icelandair
  • 8/4-15/4
  • 2 total stops
  • 45h 55m total
  • London to Seattle
Search Deals
Lufthansa
  • Lufthansa
  • 3/6
  • 1 total stop
  • 14h 09m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (£60 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 December 2025
Search Deals
Price to beat on a round-trip flight from London (LON) to Seattle/Tacoma Intl.
Search Deals
Price to beat on a one-way flight from London (LON) to Seattle/Tacoma Intl.
Search Deals

Cheapflights Fare Finder

 
Customise your flight search to find flights from London 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 10 December 2025.
Use the filters below to find and compare flights from London to Seattle that are best for you.

Fly from

London

Fly to

Seattle

Route

Depart

Return

Price

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Fri 6/3

11:55-17:00

1 stop13h 05m

Seattle/Tacoma Intl

Wed 18/3

15:35-10:55

1 stop12h 20m

£471

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Sun 1/3

11:55-17:00

1 stop13h 05m

Seattle/Tacoma Intl

Wed 18/3

15:35-10:55

1 stop12h 20m

£471

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Thu 9/4

15:40-20:40

1 stop13h 00m

Seattle/Tacoma Intl

Sun 19/4

15:40-14:40

1 stop15h 00m

£477

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Sun 12/4

15:40-20:40

1 stop13h 00m

Seattle/Tacoma Intl

Thu 16/4

19:00-14:40

1 stop11h 40m

£477

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Tue 7/4

15:40-20:40

1 stop13h 00m

Seattle/Tacoma Intl

Wed 15/4

19:00-14:40

1 stop11h 40m

£495

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Mon 6/4

15:40-20:40

1 stop13h 00m

Seattle/Tacoma Intl

Tue 14/4

19:00-14:40

1 stop11h 40m

£495

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Thu 9/4

15:40-20:40

1 stop13h 00m

Seattle/Tacoma Intl

Tue 14/4

15:40-14:40

1 stop15h 00m

£495

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 13/2

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Thu 19/2

07:15-08:15

1 stop17h 00m

£499

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 2/2

19:05-09:37

2 stops22h 32m

Seattle/Tacoma Intl

Sun 15/2

07:15-08:15

1 stop17h 00m

£517

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 1/3

08:40-11:35

1 stop34h 55m

Seattle/Tacoma Intl

Thu 19/3

19:25-11:55

Nonstop9h 30m

£519

Flights are sorted by cheapest return flights first.

Deals found on 9/12

Showing 1-10 of 60 results
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Best time to book a flight from London to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from London 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 London to Seattle

How far ahead should I book a flight from London to Seattle?

Use this chart to determine the optimal time to book a return flight from London to Seattle. Price data was last updated on 5 December 2025.

Booking 90 days in advance of your planned departure date is, on average, the best time to get cheap flights from London to Seattle. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, March is the cheapest month in which you can book a flight from London to Seattle (average of £306). Flying from London to Seattle in August is currently the most expensive (average of £463). 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 LON to SEA?

Find hourly flight availability from London 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 10 December 2025.

Unlike in the evening, when flights are generally more expensive, you can save up to 21% on flights from London to Seattle by exploring options for tickets in the morning.

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

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

Travellers seeking maximum savings on their London 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 London to Seattle

Explore weekly flight availability from London 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 10 December 2025.

The most flights from LON to SEA are scheduled on a Friday (17 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (11 on average).

How much does it cost for a return flight from London to Seattle?

What’s the top stopover airport for flights from London to Seattle?

Share of one-stop return flights from London to Seattle chosen by Cheapflights users in the past 12 months, using the same stopover each way.

Reykjavik (KEF) – chosen by Cheapflights users on 76% of one-stop itineraries from London to Seattle on Cheapflights.

What’s the cheapest stopover airport for flights from London to Seattle?

Average return fare for one-stop flights from London to Seattle, chosen by Cheapflights users in the past 12 months, with the same stopover each way.

Calgary (YYC) is the most affordable one-stop option, with an average return flight price of £393.

What’s the fastest stopover option from London to Seattle?

Shortest average travel time for one-stop one-way flights from London to Seattle, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by stopover airport.

Flights via Paris (CDG) have the shortest average one-way travel time for one-stop routes: 13h 00m.

Which airport typically offers the quickest stopover for flights from London to Seattle?

Average stopover duration for one-stop one-way flights from London to Seattle, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Salt Lake City (SLC) offer the fastest connection on this route, with an average stopover time of 0h 52m.

How often are flights from London to Seattle delayed?

About 13% of weekly flights between London and Seattle have experienced delays in the past year, with the average delay time being 117 minutes.

What is the most punctual flight time for London to Seattle flights?

Historically, flights departing in the evening are less likely to be delayed, whereas flights leaving in the early afternoon tend to experience delays more often.

What day of the week experiences the fewest flight delays on this route?

Tuesday tends to have the lowest number of delays on this route, whereas Wednesday has historically faced a higher average of delays compared to other days of the week.

Which airline has the best punctuality record on London to Seattle flights?

Over the past year, Delta have had the lowest number of delays on this route, with just 6% of flights being delayed.

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated 10 December 2025.
Read reviews from past customers who have flown with KLM, Virgin Atlantic, andAir France from London to Seattle. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
KLM
7.7
Good
1,431 reviews
Check prices

Boarding

7.8

Overall

7.7

Food

7.2

Entertainment

7.1

Crew

8.3

Comfort

7.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2025

YYC - AMS

Not literally sitting in the very last row in the middle
KLM
7.7
Good
1,431 reviews
KLM
7.7
Good
1,431 reviews
Check prices

Boarding

7.8

Overall

7.7

Food

7.2

Entertainment

7.1

Crew

8.3

Comfort

7.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2025

YYC - AMS

Not literally sitting in the very last row in the middle
Virgin Atlantic
7.5
Good
675 reviews
KLM
7.7
Good
1,431 reviews
Check prices

Boarding

7.8

Overall

7.7

Food

7.2

Entertainment

7.1

Crew

8.3

Comfort

7.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2025

YYC - AMS

Not literally sitting in the very last row in the middle
Air France
7.4
Good
1,502 reviews
KLM
7.7
Good
1,431 reviews
Check prices

Boarding

7.8

Overall

7.7

Food

7.2

Entertainment

7.1

Crew

8.3

Comfort

7.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2025

YYC - AMS

Not literally sitting in the very last row in the middle
Icelandair
7.0
Good
588 reviews
KLM
7.7
Good
1,431 reviews
Check prices

Boarding

7.8

Overall

7.7

Food

7.2

Entertainment

7.1

Crew

8.3

Comfort

7.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2025

YYC - AMS

Not literally sitting in the very last row in the middle
British Airways
6.7
Okay
7,573 reviews
KLM
7.7
Good
1,431 reviews
Check prices

Boarding

7.8

Overall

7.7

Food

7.2

Entertainment

7.1

Crew

8.3

Comfort

7.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2025

YYC - AMS

Not literally sitting in the very last row in the middle

Related info for your journey

Find useful and relevant information for your journey from London 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 London?

    Located just 11.4 mi from the city center, Seattle/Tacoma Intl is the airport most travelers will use when flying to Seattle from London. Booking flights from London to Seattle/Tacoma Intl (SEA) should be relatively easy as there are 14 daily inbound flights from London from 14 different airlines.

  • How long is the flight from London to Seattle?

    A quick flight from London to Seattle can take about 10h. Icelandair provides one of the quickest options available for as low as £499. There are 4783 mi between London and Seattle. This flight may include one or multiple stops.

  • What are the cheapest airlines flying from London to Seattle round-trip?

    Icelandair, at £327, was found to be the cheapest airline from London to Seattle.Alternate airlines flying return to your destination include Air France and Lufthansa. Icelandair is priced at 40% lower than the current average price of a flight leaving 3 months from now.

  • What are the cheapest airlines to fly from London to Seattle one-way?

    £254 is the cheapest one-way deal found within the past few days, from WestJet. You may also be able to find cheap deals on British Airways and Icelandair, with prices starting from £373 and £379, respectively.

  • What are the most popular routes from London to Seattle?

    When deciding which route to take from London to Seattle consider London Heathrow - Seattle/Tacoma Intl, London Gatwick - Seattle/Tacoma Intl or London City - Seattle/Tacoma Intl as they are the most popular.

  • What are the most reliable airlines from London to Seattle?

    Consider Scandinavian Airlines (95%), Air France (88%) or Delta (85%) when booking your flight. These represent the most reliable airlines when flying from London to Seattle.

  • What are the cheapest flights from London to Seattle?

    On average you can expect to pay £1,617 for a flight from London to Seattle. The cheapest flight overall is £373 while the most popular route, (London Heathrow - Seattle/Tacoma Intl) is currently priced at £396.

  • Can I find deals for flights from London to Seattle that include hotel bookings?

    Yes. In addition to deals on London to Seattle flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from London to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from London to Seattle.

  • Can I find deals for business class flights from London to Seattle?

    Yes. Cheapflights offers flight deals from London 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 London to Seattle?

    Currently, March is the cheapest month in which you can book a flight from London to Seattle (average of £306). Flying from London to Seattle in August is currently the most expensive (average of £463). 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
SeaTac

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Fly from London to Seattle on these airlines

Choose from the following airlines for your flight from London to Seattle. Flights are based on user searches made on Cheapflights and were last updated on 10 December 2025.
Virgin Atlantic flights from London to Seattle/Tacoma Intl
British Airways flights from London to Seattle/Tacoma Intl
Finnair flights from London to Seattle/Tacoma Intl

Top 10 airlines flying from London to Seattle

Discover the top 10 airlines that operate flights from London 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 10 December 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£327Average£485FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Air FranceCheapest£388Average£609FlexibilityNo cancel feeOn-time77%
Search Air France flights
LufthansaCheapest£398Average£491FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
FinnairCheapest£400Average£579FlexibilityNo cancel feeOn-time76%
Search Finnair flights
KLMCheapest£403Average£574FlexibilityNo cancel feeOn-time75%
Search KLM flights
United AirlinesCheapest£409Average£645FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Aer LingusCheapest£421Average£675FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
British AirwaysCheapest£441Average£601FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£445Average£592FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
DeltaCheapest£448Average£583FlexibilityNo cancel feeOn-timeN/A
Search Delta 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 London to Seattle?

Cheapflights makes it easy to find London to Seattle flights by helping our users search from 900+ travel sites for deals. We also provide you with filters for cabin, price, airline, airports, number of stops, and many more to narrow down that perfect flight.

Why should you use Cheapflights to find cheap flight tickets from London to Seattle?

Millions of users choose and trust Cheapflights to book the best flight deals from London to Seattle for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.

Can Cheapflights find flights from London to Seattle with no change fees?

Certainly. Search results for flights to Seattle from London shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

Can Cheapflights notify me if prices for flights from London to Seattle become cheaper?

Yes, Cheapflights offers price alerts on London to Seattle flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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