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$561+ Cheap flights from London (LON) to Seattle (SEA)

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 8/17. Fares are subject to change and may not be available on all flights or dates of travel.
LON — SEA
Jul 22 — Jul 291
Wed 7/22
Wed 7/29
1 adult, Economy
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Find cheap flights from London to Seattle with Cheapflights

1. Tell us where you want to go

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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 Monday or Sunday and return on a Wednesday

Cheap flight deals from London to Seattle

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 June 22, 2026.

This TravelUp deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure TravelUp is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/45:45 pm
LHR
-
SEA
Nonstop10h 18m
Virgin Atlantic
Mon 7/1310:40 pm
SEA
-
LHR
1 stop13h 30m
Virgin Atlantic
Deal found 6/19$633
This United Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/246:55 am
LHR
-
SEA
2 stops18h 47m
United Airlines
Fri 9/411:04 pm
SEA
-
LHR
1 stop23h 51m
United Airlines
Deal found 6/19$634
This British Airways deal was found by Cheapflights users on 6/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/279:25 am
LHR
-
SEA
Nonstop10h 05m
British Airways
Sun 11/82:46 pm
SEA
-
LHR
1 stop12h 49m
British Airways
Deal found 6/21$635
This The Travel House deal was found by Cheapflights users on 6/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure The Travel House is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/73:40 pm
LGW
-
SEA
1 stop34h 15m
Icelandair
Wed 9/163:40 pm
SEA
-
LGW
1 stop15h 00m
Icelandair
Deal found 6/21$636
This United Airlines deal was found by Cheapflights users on 6/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/16:50 am
LHR
-
SEA
2 stops19h 29m
United Airlines
Sun 11/18:33 am
SEA
-
LHR
1 stop17h 07m
United Airlines
Deal found 6/20$636
This United Airlines deal was found by Cheapflights users on 6/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/216:50 am
LHR
-
SEA
2 stops19h 51m
United Airlines
Mon 9/2812:43 pm
SEA
-
LHR
1 stop15h 42m
United Airlines
Deal found 6/21$637
This Gotogate deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/313:40 pm
LGW
-
SEA
1 stop28h 05m
Icelandair
Tue 9/87:00 pm
SEA
-
LGW
1 stop11h 40m
Icelandair
Deal found 6/17$638
This KLM deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/36:30 am
LHR
-
SEA
1 stop13h 03m
KLM
Sat 7/116:20 pm
SEA
-
LHR
Nonstop9h 50m
KLM
Deal found 6/19$638
This United Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/46:55 am
LHR
-
SEA
1 stop18h 04m
United Airlines
Fri 7/177:05 am
SEA
-
LHR
1 stop16h 50m
United Airlines
Deal found 6/19$639
This Delta deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/2710:00 am
LCY
-
SEA
1 stop14h 24m
Delta
Fri 7/37:30 am
SEA
-
LCY
2 stops17h 20m
Delta
Deal found 6/17$640
This Delta deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/29:55 am
LHR
-
SEA
1 stop14h 25m
Delta
Mon 7/139:50 pm
SEA
-
LHR
Nonstop9h 45m
Delta
Deal found 6/19$640
This Delta deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/410:25 am
LGW
-
SEA
1 stop15h 02m
Delta
Mon 7/136:35 pm
SEA
-
LGW
1 stop13h 25m
Delta
Deal found 6/17$641

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 June 22, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$633
(TravelUp)

One-way from

$561
(Kiwi.com)

Popular in

July

Cheapest in

February

Average price

$837

Good round-trip deal

$703 or less

Good one-way deal

$637 or less
Provider with most accurate pricing for London (LON)-Seattle/Tacoma Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for London (LON)-Seattle/Tacoma Intl flights.
Search Deals
From London (LON) to Seattle/Tacoma Intl
Search Deals
One-way flight from London (LON) to Seattle/Tacoma Intl
Search Deals
Highest demand for flights based on searches. 11% potential increase in price ($93 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($12 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 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

 
Customize 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 2,558,603 searches. Data last updated June 22, 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 round-trip
Quickest round-trip

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 10/15

9:50 am-11:35 am

Nonstop9h 45m

Seattle/Tacoma Intl

Mon 10/19

1:30 pm-6:45 am

Nonstop9h 15m

$657

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 8/18

6:55 am-4:59 pm

1 stop18h 04m

Seattle/Tacoma Intl

Mon 9/21

7:00 am-6:55 am

2 stops15h 55m

$662

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 7/3

9:30 am-11:44 pm

1 stop22h 14m

Seattle/Tacoma Intl

Thu 7/23

3:40 pm-12:25 pm

1 stop12h 45m

$666

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 7/3

5:45 pm-8:03 pm

Nonstop10h 18m

Seattle/Tacoma Intl

Tue 7/7

9:50 pm-3:35 pm

Nonstop9h 45m

$667

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 7/7

5:45 pm-8:03 pm

Nonstop10h 18m

Seattle/Tacoma Intl

Mon 7/13

6:15 pm-12:05 pm

Nonstop9h 50m

$671

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 7/4

9:30 am-5:40 pm

1 stop16h 10m

Seattle/Tacoma Intl

Fri 7/17

2:33 pm-12:25 pm

1 stop13h 52m

$674

LondonSeattle

LCY - SEA

LCYSEA

London City

Thu 10/15

6:45 am-5:10 pm

1 stop18h 25m

Seattle/Tacoma Intl

Mon 10/19

7:10 pm-8:45 pm

1 stop17h 35m

$678

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 7/16

11:25 am-1:15 am

2 stops21h 50m

Seattle/Tacoma Intl

Sun 7/26

10:44 pm-9:35 pm

1 stop14h 51m

$698

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Mon 11/23

10:00 am-10:04 pm

2 stops20h 04m

Seattle/Tacoma Intl

Mon 11/30

2:05 pm-3:45 pm

1 stop17h 40m

$705

LondonSeattle

LCY - SEA

LCYSEA

London City

Mon 11/23

7:45 am-6:59 pm

2 stops19h 14m

Seattle/Tacoma Intl

Mon 11/30

2:35 pm-4:35 pm

1 stop18h 00m

$722

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/20

Showing 1-10 of 60 resultsSorted by cheapest first
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Compare providers for flights from London to Seattle

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from London to Seattle in June.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
Justfly.comPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy2 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on London-Seattle flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on London-Seattle flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from London-Seattle flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on London-Seattle flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for London-Seattle flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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 round-trip 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 $390). Flying from London to Seattle in December is currently the most expensive (average of $1,738). 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 June 22, 2026.

When flying from London to Seattle, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

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 June 22, 2026.

The most flights from LON to SEA are scheduled on a Monday (22 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (22 on average).

How much does it cost to fly round-trip from London to Seattle?

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

Share of 1-stop round-trip flights from London to Seattle chosen by Cheapflights users in the past 12 months, using the same layover each way.

Reykjavik (KEF) – chosen by Cheapflights users on 75% of 1-stop itineraries from London to Seattle on Cheapflights.

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

Average round-trip fare for 1-stop flights from London to Seattle, chosen by Cheapflights users in the past 12 months, with the same layover each way.

Reykjavik (KEF) is the most affordable 1-stop option, with an average round-trip price of $504.

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

Shortest average travel time for 1-stop one-way flights from London to Seattle, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.

Flights via Reykjavik (KEF) have the shortest average one-way travel time for 1-stop routes: 13h 05m.

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

Average layover duration for 1-stop one-way flights from London to Seattle, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Denver (DEN) offer the fastest connection on this route, with an average layover time of 1h 25m.

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 124 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 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 last 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?

To ensure you get the cheapest price possible for a flight from London to Seattle, you should look to book at least 80 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

The best insider tips for London to Seattle flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your London to Seattle trip
Our travel experts
Ramsey Qubein

Ramsey Qubein

Expert on LHR

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

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 June 22, 2026.
See what other customers who have flown with Delta,Air France, andVirgin Atlantic from London to Seattle have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.8
Good
8,421 reviews

Entertainment

7.8

Overall

7.8

Crew

8.5

Comfort

7.8

Food

7.2

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Rakshith,May 2026

TPE - SEA

I got middle seat, but it was cheap $340 for Taipei to PDX ,
Delta
7.8
Good
8,421 reviews
Delta
7.8
Good
8,421 reviews

Entertainment

7.8

Overall

7.8

Crew

8.5

Comfort

7.8

Food

7.2

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Rakshith,May 2026

TPE - SEA

I got middle seat, but it was cheap $340 for Taipei to PDX ,
Air France
7.5
Good
1,613 reviews
Delta
7.8
Good
8,421 reviews

Entertainment

7.8

Overall

7.8

Crew

8.5

Comfort

7.8

Food

7.2

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Rakshith,May 2026

TPE - SEA

I got middle seat, but it was cheap $340 for Taipei to PDX ,
Virgin Atlantic
7.5
Good
690 reviews
Delta
7.8
Good
8,421 reviews

Entertainment

7.8

Overall

7.8

Crew

8.5

Comfort

7.8

Food

7.2

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Rakshith,May 2026

TPE - SEA

I got middle seat, but it was cheap $340 for Taipei to PDX ,
Icelandair
7.0
Good
682 reviews
Delta
7.8
Good
8,421 reviews

Entertainment

7.8

Overall

7.8

Crew

8.5

Comfort

7.8

Food

7.2

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Rakshith,May 2026

TPE - SEA

I got middle seat, but it was cheap $340 for Taipei to PDX ,
British Airways
6.7
Okay
8,064 reviews
Delta
7.8
Good
8,421 reviews

Entertainment

7.8

Overall

7.8

Crew

8.5

Comfort

7.8

Food

7.2

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Rakshith,May 2026

TPE - SEA

I got middle seat, but it was cheap $340 for Taipei to PDX ,

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?

    Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly into when you book flights from London to Seattle. 6 airlines have flights to Seattle/Tacoma Intl from London on a regular basis. Booking flights from London to Seattle/Tacoma Intl should not be difficult; the airport handles an average of 22 inbound flights from London per day.

  • How long is the flight from London to Seattle?

    For as low as $657, British Airways can have you in Seattle from London in 9h 45m. The distance from London to Seattle is about 4783 mi. Both multi-stop and nonstop flights can be found to your destination and back.

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

    Cheapflights users have booked flights from London to Seattle round-trip from $403. Other airlines that can offer you cheap pricing are KLM, from $534, and Delta, from $536. Icelandair is currently priced 46% below the average price you’ll pay for this route.

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

    One-way options have recently been found by users for as low as $368 on Icelandair. Other airlines that offer cheap prices include Aer Lingus from $469 and Lufthansa from $525 one-way.

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

    Most travelers choose London Heathrow - Seattle/Tacoma Intl, London Gatwick - Seattle/Tacoma Intl or London City - Seattle/Tacoma Intl when deciding on the best route from London to Seattle.

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

    The top 3 most reliable airlines when flying from London to Seattle are KLM (85%), Air France (85%) and Delta (85%).

  • What are the cheapest flights from London to Seattle?

    While on average a flight from London to Seattle is generally $1,332, our data shows the cheapest flight currently is $521. When looking at the most popular route, (London Heathrow - Seattle/Tacoma Intl), you can expect to pay $502 for that flight.

  • 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 vacation 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 $390). Flying from London to Seattle in December is currently the most expensive (average of $1,738). 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

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
SeaTac
Tacoma
Lacey
Leavenworth
Olympia
Ocean Shores
Renton
Edmonds
Snoqualmie
Tumwater
Tukwila
Kent
Lynnwood
Ellensburg
Fife
Marysville
Lakewood
Issaquah
Shoreline
Centralia

Browse thousands of different options on Cheapflights for your next trip

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Top 6 airlines flying from London to Seattle

Discover the top 6 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 2,558,603 searches. Data last updated June 22, 2026.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest$403Average$620FlexibilityNo cancel feeOn-time76%
KLMCheapest$485Average$796FlexibilityNo cancel feeOn-time75%
DeltaCheapest$600Average$1,009FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$618Average$985FlexibilityNo cancel feeOn-time71%
British AirwaysCheapest$661Average$895FlexibilityNo cancel feeOn-time70%
Virgin AtlanticCheapest$670Average$908FlexibilityNo cancel feeOn-time72%

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