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Cheap flights from London to Seattle from £415

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 10/1. Fares are subject to change and may not be available on all flights or dates of travel.
LON — SEA
26 Dec — 2 Jan1
1 adult
1 adult, Economy, 0 bags

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

Find 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 26 November 2025.

Wed 10/1212:15LHR - SEA
1 stop12h 45mIcelandair
Mon 5/114:35SEA - LHR
1 stop20h 55mIcelandair
Deal found 24/11£479
Tue 2/1217:15LCY - SEA
1 stop33h 05mBritish Airways
Wed 10/1220:05SEA - LCY
1 stop14h 30mBritish Airways
Deal found 25/11£485
Tue 2/1215:35LHR - SEA
2 stops51h 00mFinnair
Sat 6/1222:59SEA - LHR
1 stop24h 51mFinnair
Deal found 25/11£491
Wed 10/1207:15LCY - SEA
2 stops22h 44mBritish Airways
Mon 15/1220:05SEA - LCY
1 stop14h 30mBritish Airways
Deal found 24/11£491
Wed 24/1216:30LHR - SEA
1 stop26h 29mAmerican Airlines
Sun 28/1223:07SEA - LHR
1 stop24h 43mAmerican Airlines
Deal found 24/11£491
Thu 4/1214:55LHR - SEA
Nonstop10h 00mBritish Airways
Thu 11/1210:34SEA - LHR
1 stop14h 01mBritish Airways
Deal found 25/11£496
Tue 16/1220:45LHR - SEA
1 stop29h 35mBritish Airways
Wed 14/118:50SEA - LHR
Nonstop9h 30mBritish Airways
Deal found 26/11£499
Tue 16/1220:45LHR - SEA
1 stop29h 35mBritish Airways
Thu 15/114:04SEA - LHR
1 stop13h 31mBritish Airways
Deal found 26/11£502
Wed 24/1211:55LGW - SEA
1 stop13h 05mIcelandair
Tue 6/114:35SEA - LGW
1 stop12h 20mIcelandair
Deal found 24/11£503
Wed 10/1217:00LHR - SEA
2 stops49h 35mFinnair
Mon 15/1206:15SEA - LHR
1 stop19h 00mFinnair
Deal found 24/11£504
Thu 4/1210:05LHR - SEA
1 stop17h 07mFinnair
Wed 10/1200:31SEA - LHR
1 stop24h 04mFinnair
Deal found 25/11£507
Wed 24/1211:55LGW - SEA
1 stop13h 05mIcelandair
Mon 5/114:35SEA - LGW
1 stop12h 20mIcelandair
Deal found 24/11£512

Cheap 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 26 November 2025.

Round-trip from

£479

One-way from

£415

Popular in

July

Cheapest in

February

Average price

£545

Good round-trip deal

£560 or less

Good one-way deal

£489 or less
Icelandair
  • Icelandair
  • 10/12-5/1
  • 2 total stops
  • 33h 40m total
  • London to Seattle
Search Deals
Air Canada
  • Air Canada
  • 10/1
  • 1 total stop
  • 19h 06m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (£58 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 November 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 26 November 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

LHR - SEA

LHRSEA

London Heathrow

Fri 13/2

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Thu 19/2

10:30-08:15

1 stop13h 45m

£486

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 8/2

12:20-14:45

Nonstop10h 25m

Seattle/Tacoma Intl

Wed 4/3

16:45-10:30

Nonstop9h 45m

£486

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 15/1

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Wed 28/1

08:35-06:50

1 stop14h 15m

£491

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/2

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Sun 1/3

18:50-12:20

Nonstop9h 30m

£499

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 7/2

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Tue 3/3

18:50-12:20

Nonstop9h 30m

£499

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 7/2

09:25-11:30

Nonstop10h 05m

Seattle/Tacoma Intl

Thu 26/2

18:50-12:20

Nonstop9h 30m

£499

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 11/2

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Sat 28/2

18:50-12:20

Nonstop9h 30m

£499

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 27/2

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Sat 14/3

19:50-12:20

Nonstop9h 30m

£502

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 19/1

09:00-21:12

2 stops20h 12m

Seattle/Tacoma Intl

Tue 27/1

10:58-13:00

2 stops18h 02m

£523

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 20/5

09:50-11:35

Nonstop9h 45m

Seattle/Tacoma Intl

Sat 23/5

13:35-06:50

Nonstop9h 15m

£525

Flights are sorted by cheapest return flights first.

Deals found on 25/11

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 21 November 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 £310). Flying from London 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 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 26 November 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 26 November 2025.

The most flights from LON to SEA are scheduled on a Monday (15 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (11 on average).

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 77% 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 £398.

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 26 November 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
1,422 reviews
Check prices

Entertainment

7.1

Overall

7.7

Crew

8.4

Boarding

7.8

Comfort

7.6

Food

7.2

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.
KLM
7.7
Good
1,422 reviews
KLM
7.7
Good
1,422 reviews
Check prices

Entertainment

7.1

Overall

7.7

Crew

8.4

Boarding

7.8

Comfort

7.6

Food

7.2

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.
Virgin Atlantic
7.5
Good
675 reviews
KLM
7.7
Good
1,422 reviews
Check prices

Entertainment

7.1

Overall

7.7

Crew

8.4

Boarding

7.8

Comfort

7.6

Food

7.2

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.
Air France
7.4
Good
1,497 reviews
KLM
7.7
Good
1,422 reviews
Check prices

Entertainment

7.1

Overall

7.7

Crew

8.4

Boarding

7.8

Comfort

7.6

Food

7.2

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.
Icelandair
7.0
Good
581 reviews
KLM
7.7
Good
1,422 reviews
Check prices

Entertainment

7.1

Overall

7.7

Crew

8.4

Boarding

7.8

Comfort

7.6

Food

7.2

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.
British Airways
6.7
Okay
7,539 reviews
KLM
7.7
Good
1,422 reviews
Check prices

Entertainment

7.1

Overall

7.7

Crew

8.4

Boarding

7.8

Comfort

7.6

Food

7.2

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.

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 12 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. British Airways provides one of the quickest options available for as low as £486. There are 4783 mi between London and Seattle. All flights are typically direct.

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

    Icelandair, at £351, was found to be the cheapest airline from London to Seattle.Alternate airlines flying return to your destination include Air France and Finnair. Icelandair is priced at 37% 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?

    £418 is the cheapest one-way deal found within the past few days, from British Airways. You may also be able to find cheap deals on SWISS and Icelandair, with prices starting from £431 and £482, 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 (86%) or KLM (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 £1,733 for a flight from London to Seattle. The cheapest flight overall is £378 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 £310). Flying from London 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

Browse thousands of different options on Cheapflights for your next trip

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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 26 November 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 26 November 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£332Average£479FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Air FranceCheapest£393Average£617FlexibilityNo cancel feeOn-time77%
Search Air France flights
FinnairCheapest£405Average£581FlexibilityNo cancel feeOn-time76%
Search Finnair flights
LufthansaCheapest£408Average£499FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
KLMCheapest£409Average£581FlexibilityNo cancel feeOn-time75%
Search KLM flights
United AirlinesCheapest£414Average£652FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
British AirwaysCheapest£449Average£610FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£451Average£600FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
DeltaCheapest£454Average£591FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Aer LingusCheapest£466Average£683FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus 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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