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Cheap flights from London to Seattle from £417

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 24/9. Fares are subject to change and may not be available on all flights or dates of travel.
LON — SEA
17 Aug — 24 Aug1
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 Thursday

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 18 July 2026.

Thu 12/1107:30
LHR
-
SEA
2 stops21h 19m
United Airlines
Thu 12/1123:16
SEA
-
LHR
2 stops23h 54m
United Airlines
Deal found 16/7£445
Tue 1/909:50
LHR
-
SEA
Nonstop9h 45m
British Airways
Fri 18/913:30
SEA
-
LHR
Nonstop9h 15m
British Airways
Deal found 14/7£447
Fri 16/1015:40
LGW
-
SEA
1 stop13h 00m
Icelandair
Mon 19/1015:40
SEA
-
LGW
1 stop15h 00m
Icelandair
Deal found 17/7£447
Fri 14/810:45
LHR
-
SEA
1 stop19h 20m
Delta
Sat 22/821:45
SEA
-
LHR
Nonstop9h 50m
Delta
Deal found 13/7£447
Mon 10/809:50
LHR
-
SEA
Nonstop9h 45m
British Airways
Sat 22/813:30
SEA
-
LHR
Nonstop9h 15m
British Airways
Deal found 13/7£448
Tue 1/913:00
LGW
-
SEA
1 stop12h 55m
Icelandair
Sat 31/1015:35
SEA
-
LGW
1 stop12h 20m
Icelandair
Deal found 16/7£450
Thu 13/809:50
LHR
-
SEA
Nonstop9h 45m
British Airways
Wed 19/820:20
SEA
-
LHR
Nonstop9h 25m
British Airways
Deal found 13/7£450
Sun 30/815:40
LGW
-
SEA
1 stop28h 05m
Icelandair
Sun 6/919:00
SEA
-
LGW
1 stop32h 45m
Icelandair
Deal found 16/7£450
Wed 9/913:05
LHR
-
SEA
1 stop12h 50m
Multiple Airlines
Tue 4/507:55
SEA
-
LHR
2 stops17h 10m
Multiple Airlines
Deal found 14/7£450
Tue 11/816:30
LHR
-
SEA
Nonstop9h 55m
British Airways
Sun 23/820:20
SEA
-
LHR
Nonstop9h 25m
British Airways
Deal found 13/7£451
Sun 30/821:25
LHR
-
SEA
1 stop28h 30m
Icelandair
Sun 6/919:00
SEA
-
LHR
1 stop17h 20m
Icelandair
Deal found 16/7£452
Tue 1/1212:15
LHR
-
SEA
1 stop12h 45m
Icelandair
Tue 15/1214:35
SEA
-
LHR
1 stop12h 15m
Icelandair
Deal found 16/7£453

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 18 July 2026.

Round-trip from

£445

One-way from

£417

Popular in

December

Cheapest in

February

Average price

£626

Good round-trip deal

£498 or less

Good one-way deal

£417 or less
United Airlines
  • United Airlines
  • 12/11-12/11
  • 4 total stops
  • 45h 13m total
  • London to Seattle
Search Deals
SWISS
  • SWISS
  • 24/9
  • 2 total stops
  • 17h 17m 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 July 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 18 July 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

LHR - SEA

LHRSEA

London Heathrow

Fri 28/8

09:00-16:59

1 stop15h 59m

Seattle/Tacoma Intl

Fri 4/9

15:34-20:40

1 stop21h 06m

£527

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 30/8

09:00-16:59

1 stop15h 59m

Seattle/Tacoma Intl

Sat 19/9

15:54-12:25

1 stop12h 31m

£531

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 4/9

08:55-16:41

1 stop15h 46m

Seattle/Tacoma Intl

Mon 7/9

13:30-06:45

Nonstop9h 15m

£556

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 17/8

13:35-16:59

1 stop35h 24m

Seattle/Tacoma Intl

Wed 2/9

18:52-20:40

2 stops17h 48m

£561

LondonSeattle

LCY - SEA

LCYSEA

London City

Tue 15/9

20:15-11:47

1 stop23h 32m

Seattle/Tacoma Intl

Fri 25/9

13:50-11:40

1 stop13h 50m

£563

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 13/8

17:45-20:03

Nonstop10h 18m

Seattle/Tacoma Intl

Sat 29/8

21:45-15:35

Nonstop9h 50m

£595

LondonSeattle

LCY - SEA

LCYSEA

London City

Mon 7/12

18:55-11:50

1 stop24h 55m

Seattle/Tacoma Intl

Tue 15/12

06:00-08:50

2 stops18h 50m

£608

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 21/8

11:40-14:00

Nonstop10h 20m

Seattle/Tacoma Intl

Wed 9/9

17:30-11:20

Nonstop9h 50m

£608

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Wed 4/11

10:00-22:12

2 stops20h 12m

Seattle/Tacoma Intl

Fri 6/11

11:15-15:45

2 stops20h 30m

£610

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Tue 3/11

08:00-17:00

1 stop17h 00m

Seattle/Tacoma Intl

Tue 17/11

14:35-17:30

1 stop18h 55m

£611

Flights are sorted by cheapest return flights first.

Deals found on 14/7

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, October is the cheapest month in which you can book a flight from London to Seattle (average of £267). Flying from London to Seattle in December is currently the most expensive (average of £1,269). 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 18 July 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 18 July 2026.

The most flights from LON to SEA are scheduled on a Tuesday (24 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?

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 75% 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 £452.

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 10% 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 18 July 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
12,670 reviews
Check prices

Entertainment

7.0

Crew

8.5

Food

7.0

Overall

7.9

Boarding

8.1

Comfort

7.8

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
12,670 reviews
Alaska Airlines
7.9
Good
12,670 reviews
Check prices

Entertainment

7.0

Crew

8.5

Food

7.0

Overall

7.9

Boarding

8.1

Comfort

7.8

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
1,541 reviews
Alaska Airlines
7.9
Good
12,670 reviews
Check prices

Entertainment

7.0

Crew

8.5

Food

7.0

Overall

7.9

Boarding

8.1

Comfort

7.8

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
693 reviews
Alaska Airlines
7.9
Good
12,670 reviews
Check prices

Entertainment

7.0

Crew

8.5

Food

7.0

Overall

7.9

Boarding

8.1

Comfort

7.8

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
710 reviews
Alaska Airlines
7.9
Good
12,670 reviews
Check prices

Entertainment

7.0

Crew

8.5

Food

7.0

Overall

7.9

Boarding

8.1

Comfort

7.8

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
8,122 reviews
Alaska Airlines
7.9
Good
12,670 reviews
Check prices

Entertainment

7.0

Crew

8.5

Food

7.0

Overall

7.9

Boarding

8.1

Comfort

7.8

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 15h 46m. United Airlines provides one of the quickest options available for as low as £556. 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?

    Lufthansa, at £334, 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?

    £352 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 KLM, with prices starting from £363 and £391, 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 (88%), KLM (79%) or Air France (79%) 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 £1,420 for a flight from London to Seattle. The cheapest flight overall is £343 while the most popular route, (London Heathrow - Seattle/Tacoma Intl) is currently priced at £369.

  • 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, October is the cheapest month in which you can book a flight from London to Seattle (average of £267). Flying from London to Seattle in December is currently the most expensive (average of £1,269). 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
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 18 July 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 18 July 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£334Average£525FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
IcelandairCheapest£340Average£501FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Aer LingusCheapest£390Average£615FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
Virgin AtlanticCheapest£423Average£585FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
United AirlinesCheapest£429Average£639FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
KLMCheapest£436Average£612FlexibilityNo cancel feeOn-time75%
Search KLM flights
DeltaCheapest£440Average£636FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air FranceCheapest£449Average£636FlexibilityNo cancel feeOn-time77%
Search Air France flights
British AirwaysCheapest£456Average£637FlexibilityNo cancel feeOn-time70%
Search British Airways flights
FinnairCheapest£473Average£673FlexibilityNo cancel feeOn-time76%
Search Finnair 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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