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Cheap flights from London to Seattle from £400

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 16/10. Fares are subject to change and may not be available on all flights or dates of travel.
LON — SEA
1 Sep — 8 Sep1
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 83 days in advance, depart on a Thursday or Wednesday 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 2 August 2026.

Wed 4/1112:15
LHR
-
SEA
1 stop12h 45m
Multiple Airlines
Mon 23/1108:31
SEA
-
LHR
2 stops15h 34m
Multiple Airlines
Deal found 29/7£448
Mon 2/1120:35
LHR
-
SEA
1 stop28h 25m
Multiple Airlines
Tue 24/1108:31
SEA
-
LHR
2 stops15h 34m
Multiple Airlines
Deal found 29/7£449
Sun 1/1120:35
LHR
-
SEA
1 stop28h 25m
Multiple Airlines
Tue 24/1108:31
SEA
-
LHR
2 stops15h 34m
Multiple Airlines
Deal found 29/7£449
Sat 26/916:15
LHR
-
SEA
1 stop25h 48m
United Airlines
Sun 27/913:00
SEA
-
LHR
1 stop23h 40m
United Airlines
Deal found 28/7£451
Sun 25/1013:35
LHR
-
SEA
1 stop29h 44m
Lufthansa
Tue 27/1010:40
SEA
-
LHR
1 stop13h 45m
Lufthansa
Deal found 1/8£452
Fri 2/1008:00
LHR
-
SEA
2 stops21h 01m
United Airlines
Fri 2/1023:14
SEA
-
LHR
1 stop23h 41m
United Airlines
Deal found 28/7£453
Tue 6/1015:40
LGW
-
SEA
1 stop13h 00m
Icelandair
Mon 12/1019:00
SEA
-
LGW
1 stop11h 40m
Icelandair
Deal found 30/7£454
Wed 28/1012:15
LHR
-
SEA
1 stop12h 45m
Icelandair
Thu 5/1114:35
SEA
-
LHR
1 stop12h 15m
Icelandair
Deal found 29/7£454
Tue 6/1021:25
LHR
-
SEA
1 stop28h 30m
Icelandair
Mon 12/1015:40
SEA
-
LHR
1 stop12h 15m
Icelandair
Deal found 30/7£456
Tue 22/915:40
LGW
-
SEA
1 stop13h 00m
Icelandair
Wed 30/915:40
SEA
-
LGW
1 stop15h 00m
Icelandair
Deal found 30/7£458
Wed 18/1112:15
LHR
-
SEA
1 stop12h 45m
Multiple Airlines
Sun 29/1108:31
SEA
-
LHR
2 stops15h 34m
Multiple Airlines
Deal found 29/7£459
Wed 4/1112:15
LHR
-
SEA
1 stop12h 45m
Multiple Airlines
Sun 29/1108:31
SEA
-
LHR
2 stops15h 34m
Multiple Airlines
Deal found 29/7£460

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 2 August 2026.

Round-trip from

£448

One-way from

£400

Popular in

December

Cheapest in

February

Average price

£592

Good round-trip deal

£518 or less

Good one-way deal

£416 or less
4/11-23/11
  • 4/11-23/11
  • 3 total stops
  • 28h 19m total
  • London to Seattle
Search Deals
Iberia
  • Iberia
  • 16/10
  • 2 total stops
  • 20h 40m total
  • London to Seattle
Search Deals
High demand for flights, 0% potential price rise
Search Deals
Cheapest flight prices on average. 1% potential price decrease (£6 potential savings vs. average return price).
Search Deals
Average for round-trip flights in August 2026
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 2 August 2026.
Use the filters below to find and compare flights from London to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Tue 22/9

15:40-20:40

1 stop13h 00m

Seattle/Tacoma Intl

Sat 17/10

15:40-14:35

1 stop14h 55m

£517

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Sun 18/10

15:40-17:55

1 stop34h 15m

Seattle/Tacoma Intl

Tue 3/11

14:35-10:55

1 stop12h 20m

£520

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 16/9

10:50-16:59

1 stop14h 09m

Seattle/Tacoma Intl

Fri 25/9

09:05-09:40

2 stops16h 35m

£523

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 12/12

06:30-12:00

1 stop13h 30m

Seattle/Tacoma Intl

Sun 13/12

15:15-11:50

1 stop12h 35m

£528

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 13/9

07:30-19:14

2 stops19h 44m

Seattle/Tacoma Intl

Wed 23/9

13:16-14:10

1 stop16h 54m

£528
Fastest return journey

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 28/8

06:30-11:37

1 stop13h 07m

Seattle/Tacoma Intl

Sat 12/9

21:50-15:35

Nonstop9h 45m

£549

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 2/9

08:55-16:41

1 stop15h 46m

Seattle/Tacoma Intl

Wed 16/9

13:30-06:45

Nonstop9h 15m

£555

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 25/8

06:50-18:41

2 stops19h 51m

Seattle/Tacoma Intl

Tue 1/9

05:00-07:15

2 stops18h 15m

£556

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Sat 10/10

10:25-23:04

2 stops20h 39m

Seattle/Tacoma Intl

Tue 10/11

07:15-15:45

2 stops24h 30m

£559

LondonSeattle

LCY - SEA

LCYSEA

London City

Wed 14/10

19:00-11:52

1 stop24h 52m

Seattle/Tacoma Intl

Wed 28/10

15:25-17:20

1 stop18h 55m

£561

Flights are sorted by cheapest return flights first.

Deals found on 29/7

Showing 1-10 of 60 resultsSorted by cheapest first
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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

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

Currently, February is the cheapest month in which you can book a flight from London to Seattle (average of £480). Flying from London to Seattle in December is currently the most expensive (average of £639). 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 2 August 2026.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from London to Seattle as you normally would.

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 2 August 2026.

The most flights from LON to SEA are scheduled on a Friday (29 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (18 on average).

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

Airfare is below average for this route at the moment.
London to Seattle flights typically cost between £520 and £678 in November.
The cheapest return price found within the last 5 days was £448 on Multiple Airlines (4 Nov–23 Nov).

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 80% 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.

Zurich (ZRH) is the most affordable one-stop option, with an average return flight price of £451.

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 Vancouver (YVR) have the shortest average one-way travel time for one-stop routes: 12h 26m.

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 Helsinki (HEL) offer the fastest connection on this route, with an average stopover time of 1h 03m.

How often are flights from London to Seattle delayed?

About 11% of weekly flights between London and Seattle have experienced delays in the past year, with the average delay time being 128 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?

Thursday tends to have the lowest number of delays on this route, whereas Tuesday 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 5% of flights being delayed.

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

Booking 80 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.

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 2 August 2026.
Read reviews from past customers who have flown with Alaska Airlines,KLM, andVirgin Atlantic 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.
Alaska Airlines
7.9
Good
12,749 reviews
Check prices

Entertainment

7.0

Food

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Overall

7.9

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
Alaska Airlines
7.9
Good
12,749 reviews
Alaska Airlines
7.9
Good
12,749 reviews
Check prices

Entertainment

7.0

Food

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Overall

7.9

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
KLM
7.8
Good
1,552 reviews
Alaska Airlines
7.9
Good
12,749 reviews
Check prices

Entertainment

7.0

Food

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Overall

7.9

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
Virgin Atlantic
7.5
Good
694 reviews
Alaska Airlines
7.9
Good
12,749 reviews
Check prices

Entertainment

7.0

Food

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Overall

7.9

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
Icelandair
7.0
Good
719 reviews
Alaska Airlines
7.9
Good
12,749 reviews
Check prices

Entertainment

7.0

Food

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Overall

7.9

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
British Airways
6.7
Okay
8,140 reviews
Alaska Airlines
7.9
Good
12,749 reviews
Check prices

Entertainment

7.0

Food

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Overall

7.9

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.

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 23 daily inbound flights from London from 13 different airlines.

  • How long is the flight from London to Seattle?

    A quick flight from London to Seattle can take about 13h. Icelandair provides one of the quickest options available for as low as £517. There are 4807 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?

    Lufthansa, at £333, was found to be the cheapest airline from London to Seattle.Alternate airlines flying return to your destination include Icelandair and Aer Lingus. Lufthansa is priced at 39% 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?

    £351 is the cheapest one-way deal found within the past few days, from Icelandair. You may also be able to find cheap deals on British Airways and Virgin Atlantic, with prices starting from £362 and £365, 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 Stansted - Seattle/Tacoma Intl as they are the most popular.

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

    Consider Scandinavian Airlines (85%), KLM (77%) or Air France (77%) 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 £1,814 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 £410.

  • 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, February is the cheapest month in which you can book a flight from London to Seattle (average of £480). Flying from London to Seattle in December is currently the most expensive (average of £639). 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
Federal Way
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 2 August 2026.
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 2 August 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£333Average£525FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
IcelandairCheapest£339Average£499FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Aer LingusCheapest£389Average£616FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
Virgin AtlanticCheapest£422Average£583FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
United AirlinesCheapest£428Average£653FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
KLMCheapest£434Average£607FlexibilityNo cancel feeOn-time75%
Search KLM flights
DeltaCheapest£439Average£641FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air FranceCheapest£448Average£631FlexibilityNo cancel feeOn-time77%
Search Air France flights
British AirwaysCheapest£455Average£637FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Alaska AirlinesCheapest£468Average£594FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines 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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