LON - SEA

€463 Find Cheap Flights from London to Seattle – Compare and Save

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Everything you should know

Cheapest return flight
€492
Typical prices: €607-€841
Alaska Airlines
Fri 23/11Thu 6/12
LHR - SEA • Direct
Cheapest one-way flight
€463
Typical prices: €515-€821
United Airlines
Thu 8/2
LHR - SEA • 2 stops
Direct flights
You can fly direct with British Airways, Alaska Airlines, and others. Average duration is 10h 10m.
Direct flights
+1
Direct flights
+1
Top routes
Cheapest • 18% average savings
Most popular
Insights
Insights
Avoid delays
Most punctual • 95% on-time
Best time • Fewest delays
Insights
Insights
When to book
in advance
Our data shows that travellers who book at least 15 weeks in advance save around 27% compared to booking last minute.
Insights
Insights
When to travel
Cheapest • 22% price drop
Most popular
Good to know
+1
Good to know
+1
Top stopover airports
Cheapest • Avg €541 (return)
Shortest trip • 13h 19m (one-way)
Insights
Insights
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We hope you enjoy your trip to Seattle!
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Booking Insights
Flight Deals

Cheap Flights from London to Seattle (LON-SEA)

 
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent return flight deals from London to Seattle

Mon, 23 Nov - Sun, 6 Dec
Alaska Airlines Logo
14:45 - 17:00LHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 15mdirect
Alaska Airlines Logo
18:45 - 12:20SEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 35mdirect
€492Alaska Airlines
Sun, 13 Dec - Wed, 20 Jan
Alaska Airlines Logo
14:45 - 17:00LHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 15mdirect
Alaska Airlines Logo
18:40 - 12:20SEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 40mdirect
€510Alaska Airlines
Thu, 29 Oct - Wed, 11 Nov
Alaska Airlines Logo
14:45 - 18:05LHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 20mdirect
Alaska Airlines Logo
18:45 - 12:20SEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 35mdirect
€511Alaska Airlines
Thu, 28 Jan - Fri, 5 Feb
Alaska Airlines Logo
14:45 - 16:50LHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 05mdirect
Alaska Airlines Logo
18:40 - 12:20SEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 40mdirect
€513Alaska Airlines
Thu, 14 Jan - Mon, 18 Jan
Alaska Airlines Logo
14:45 - 16:50LHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 05mdirect
Alaska Airlines Logo
18:40 - 12:20SEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 40mdirect
€514Alaska Airlines
Thu, 14 Jan - Mon, 18 Jan
Alaska Airlines Logo
14:45 - 16:50LHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 05mdirect
Alaska Airlines Logo
18:40 - 12:20SEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 40mdirect
€515Alaska Airlines
Mon, 9 Nov - Thu, 1 Apr
Icelandair Logo
20:35 - 17:00LHR  London Heathrow-SEA Seattle/Tacoma Intl
28h 25m1 stop Reykjavik Keflavik Intl
Icelandair Logo
19:00 - 11:55SEA  Seattle/Tacoma Intl-LHR London Heathrow
32h 55m1 stop Reykjavik Keflavik Intl
€516Icelandair
Thu, 1 Apr - Sat, 24 Apr
Alaska Airlines Logo
17:00 - 19:10LHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 10mdirect
Alaska Airlines Logo
21:30 - 15:05SEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 35mdirect
€518Alaska Airlines
Tue, 30 Mar - Mon, 19 Apr
Icelandair Logo
21:25 - 20:40LHR  London Heathrow-SEA Seattle/Tacoma Intl
31h 15m1 stop Reykjavik Keflavik Intl
Icelandair Logo
15:40 - 11:55SEA  Seattle/Tacoma Intl-LHR London Heathrow
12h 15m1 stop Reykjavik Keflavik Intl
€519Icelandair
Mon, 9 Nov - Wed, 31 Mar
Icelandair Logo
20:35 - 17:00LHR  London Heathrow-SEA Seattle/Tacoma Intl
28h 25m1 stop Reykjavik Keflavik Intl
Icelandair Logo
19:00 - 20:20SEA  Seattle/Tacoma Intl-LHR London Heathrow
17h 20m1 stop Reykjavik Keflavik Intl
€522Icelandair
Booking Insights

Price, demand, and travel trends for London to Seattle flights

Use KAYAK data on prices, travel dates, airlines, and seasonal trends to compare options and book flights with more confidence.

How much is a return flight from London to Seattle?

Return flights from London to Seattle typically range from €607 to €841. The lowest price found in the past 5 days was €492 on Alaska Airlines.

What is the cheapest London to Seattle flight route?

London Gatwick Airport (LGW) to Seattle (SEA) is the cheapest London to Seattle route, averaging €593 return. Other London to Seattle routes average €770, based on KAYAK data over the past 12 months.

What's the cheapest day of the week to fly from London to Seattle?

Based on deals KAYAK users found in the last 12 months, Wednesday is the cheapest day of the week to fly from London to Seattle. It’s 4% cheaper than the average day, while Sunday is the most expensive, with prices 6% higher.

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

•February is the cheapest month to fly from London to Seattle at €562 return.
•June (€772) and July (€770) are the most expensive months.
•The price difference between flying in the cheapest and most expensive months is 37% on average.
This is based on KAYAK aggregated and averaged internal data over the past 12 months.

When are flights from London to Seattle the cheapest?

Flights from London to Seattle are cheapest 15 weeks before departure. Booking in this window typically costs about 27% less than the average last-minute fare (within 2 weeks of the flight), based on KAYAK data.

Key details for London to Seattle flights

Low season

February

Cheapest flight

€463
Beat the crowds with an average 47% drop in traveller numbers.
The most popular month to fly with an average 90% increase in traveller numbers.
One-way flight from London Heathrow Airport to Seattle

When to book flights from London to Seattle

Are your dates flexible? Find out the best times to travel from London to Seattle based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated return price

Your London to Seattle flight questions, answered

Find helpful answers about this route, including flight times, airports, airlines, and booking tips.

  • What are the earliest and latest flights from London to Seattle?

    These are the earliest and latest flight times available from London to Seattle:

    • Earliest: departs at 09:25 and lands at 19:35
    • Latest: departs at 18:30 and lands at 04:40.

    The flight takes about 10h 10m.

  • Which cabin classes can I book on flights from London to Seattle?

    Only Economy class is available on flights from London to Seattle.

  • How long is a flight from London to Seattle?

    A direct flight from London to Seattle takes 10h 10m, covering 12,406 km.

  • Do I need a passport to fly from London to Seattle?

    Yes, a valid passport is required for this international route. Many destinations require at least six months of validity beyond your travel dates. Check your passport expiry well before booking.

  • How much should I expect to pay for a London to Seattle flight?

    Return flights from London to Seattle range from €607 to €841, with an average of €721 over the past 12 months. Anything below €607 counts as a good deal.

  • How expensive are last-minute London to Seattle flights?

    Last-minute fares on this route (booked within two weeks of departure) run 22% above the €721 route average. Book 15 weeks before departure for the lowest fares.

  • How much can I save by having a stopover when flying from London to Seattle?

    On this route, stopover flights are cheaper than direct options on average. Stopover fares average €541 return via Zurich (ZRH), compared with €740 for direct.

  • How does on-time performance compare across airlines flying from London to Seattle?

    Delta is slightly above the route average for timely arrivals, while Virgin Atlantic has a lower on-time arrival rate. On-time arrival rates on London to Seattle flights are:

    • Delta: 95% on time
    • Virgin Atlantic: 90% on time
    • British Airways: 86% on time

    On average, flights on this route are punctual 88% of the time.

  • What is the standard checked bag allowance on flights from London to Seattle?

    There is no standard. Checked bag policies vary by airline on this route. Most carriers charge €46–€89 for the first checked bag in Economy. Premium fares and elite status bookings typically include a free checked bag.

  • How are flight departures from London to Seattle spread across the day?

    Afternoon is the busiest departure period on London to Seattle flights, with 75% leaving in that window. Morning departures account for 25%, Evening flights for 0%, and Night flights for 0%.

  • Which airlines offer Wi-Fi on London to Seattle flights?

    Four airlines offer in-flight Wi-Fi on London to Seattle flights:

    • Virgin Atlantic
    • Air France
    • Delta
    • KLM

    Pricing varies by airline and fare class. Some plans are included with the ticket or loyalty programme, while others are paid add-ons priced by flight length.

  • How are flight prices from London to Seattle looking right now?

    One-way fares from London to Seattle are currently lower than usual. Average one-way flight prices are about €470, which is 23% below the typical average for this route.

  • Which car hire options are available at Seattle/Tacoma Intl Airport (SEA)?

    Seattle/Tacoma Intl Airport (SEA) hosts 5 major car hire companies, with daily rates starting from around €3 for economy cars. Top options include:

    • Fox
    • Europcar
    • Thrifty
    • Budget
    • Hertz

  • Which airports can I use when flying from London to Seattle?

    Flights from London to Seattle may depart from several airports in London area, including London City (LCY), London Gatwick (LGW), London Heathrow (LHR), London Luton (LTN), London Southend (SEN) and London Stansted (STN). Flights usually arrive at Seattle/Tacoma Intl (SEA).

  • What time of day has the fewest delays on flights from London to Seattle?

    Evening flights have the fewest delays on this route, while afternoon departures tend to have the most.

  • At what point is a flight considered delayed on the route from London to Seattle?

    A flight is considered delayed when it departs 15 minutes or more after its scheduled time. This is the standard used by the US Department of Transportation and most airline industry reporting. On the London to Seattle route, 12% of flights were delayed in the past three months, with delays averaging 2h 20m.

  • Which airports do connecting flights from London to Seattle pass through?

    One-stop flights from London to Seattle most commonly connect through:

    • Reykjavik Keflavik Intl (KEF) – 69% of one-stop connections
    • Dublin (DUB) – 16% of one-stop connections
    • Frankfurt am Main (FRA) – 4% of one-stop connections
    • Kastrup Copenhagen (CPH) – 3% of one-stop connections

  • Can I save money by using flexible dates for flights from London to Seattle?

    Yes. Flexible dates can save you up to 10% on flights from London to Seattle. Wednesday is the cheapest departure day at €695 return on average, while Sunday is the most expensive at €770, a difference of €75.

    KAYAK's flexible dates feature shows options up to three days before and after your selected dates, making it easier to compare nearby fares.

  • Which airlines fly from London to Seattle?

    4 airlines operate flights between London and Seattle. The airlines offering direct flights on this route include:

    • British Airways
    • Alaska Airlines
    • Delta
    • Virgin Atlantic

  • How much time can I save by choosing a different stopover airport from London to Seattle?

    Flying via Zurich (ZRH) gives the shortest average 1-stop total travel time of 13h 12m, compared to 13h 19m via Calgary (YYC) and 13h 32m via Denver Intl (DEN).

  • What is the time difference between London and Seattle?

    Seattle is 8 hours behind London (Pacific Time vs British Time). Plan for the time shift when scheduling connections or first-day activities.

  • What popular places can I visit in Seattle?

    Seattle Marriott Waterfront is one of the most viewed places in Seattle on KAYAK.

  • Which airlines offer extra legroom and free seat selection on London to Seattle flights?

    Among airlines operating London to Seattle flights:

    • Alaska Airlines: offers free seat selection
    • Virgin Atlantic: offers extra legroom; offers free seat selection
    • British Airways: offers free seat selection
    • Delta: offers extra legroom; offers free seat selection
    • KLM: offers extra legroom; offers free seat selection

    Extra legroom and free seat selection availability depends on fare class and route.

  • Which airlines include bags at no extra cost on London to Seattle flights?

    Here are some options for this route, based on selected ticket types and cabin classes:

    • Alaska Airlines: a cabin bag and a checked bag in Economy class
    • Virgin Atlantic: a cabin bag and a checked bag in Economy class
    • British Airways: a cabin bag and a checked bag in Economy class

    Baggage allowance can vary by ticket type, cabin class, route, and airline, so always check the fare details before booking.

  • Are there any passenger lounges at Stansted Airport?

    Those flying from London’s Stansted Airport (STN) can relax in style at the Escape Lounge. You can find this lounge in the main departure area once you have passed through security and the duty-free area. You can pre-book your entry into the lounge for £25 per person, however infants younger than 2 years can enter free of charge. The lounge is open from 4:00 – 22:30 daily.

  • How do I travel from Seattle Airport into the city?

    If you would like to use public transport to travel into the city from Seattle Airport, you can catch the Red Line of the Link Light Rail train system from the airport station to Pioneer Square Station in downtown Seattle. The trip takes about 40min. There are also a number of bus services that can take you throughout the greater Seattle area, including the 574 line to Tacoma, taking approximately 30min.

  • How do I get to Gatwick Airport?

    The fastest way to get to London’s Gatwick Airport (LGW) using public transport from Central London is to take the Gatwick Express train. You can catch this train from Victoria Station every day from 5:00 – midnight. This train runs every 15min, stopping at Gatwick Airport’s South Terminal and taking 30min. Alternatively, the Thameslink also runs to Gatwick Airport in 30min from London Bridge Station every 20min.

  • What restaurants are there at Heathrow Airport?

    If you have time before you fly from Heathrow Airport (LHR), you can enjoy a wide range of restaurants and dining options throughout the airport, depending on which terminal you are flying from. If you’re looking for a sit-down meal, you can find the Gorgeous Kitchen in Terminal 2, The Curator or The Cavier House & Prunier in Terminal 3, The Prince of Wales or Comptoir Libanais in Terminal 4 or the Crown Rivers Bar & Food at Terminal 5.

Your guide to booking London to Seattle flights

Get tips on when to book, when to fly, and what to know before your trip.
  • If your dates are flexible, aim for a Wednesday departure and avoid flying on Sunday. On this route, Wednesday flights average €695, about €75 less than Sunday fares (10% savings) based on the last 12 months.
  • For the best chance at a low fare, aim to book around 15 weeks before you fly. On this route, that window historically saves about 27% versus last-minute pricing (KAYAK booking data, last 12 months).
  • If you can choose when to travel, plan your London to Seattle trip for February. Fares historically average €562 return in that month – typically €209 less than the most expensive month, which is June (based on the last 12 months).
  • For the best chance of arriving on time, fly with Delta. Over the past three months, 95% of Delta flights from London to Seattle arrived on time, slightly above the route average of 88%. When flights on this route arrive late, they're delayed by an average of 2h 20m, so choosing an airline with strong on-time performance can make a difference if you're on a tight schedule.
  • If you have the time, taking a 1-stop flight through Zurich Airport (ZRH) can be cheaper than flying direct. The cheapest stopover option averages €541 return on this route – about €200 less than direct flights (based on the last 12 months).
  • If you're arriving late at night and need somewhere to stay, check out these hotels close to Seattle/Tacoma Intl Airport.

    • Coast Gateway Hotel
    • Seattle Airport Marriott
    • Fairfield by Marriott Inn & Suites Seattle Sea-Tac Airport
  • Seattle-Tacoma Airport (SEA) is located approximately 20min from downtown Seattle and serves nearby cities in northern Washington state, including Olympia (1h 15min away), Everett (1h 15min away) and Tacoma (45min away).
  • Before your flight from London to Seattle, you will need to register your travel plans. The UK has a visa waiver agreement with the USA and British Passport holders can apply online for the Electronic System for Travel Authorization (ESTA). This grants you entry into the USA and travel for up to 90 days.
  • If you’re not in Seattle long and would like to explore the city without all of your luggage, you can store your bags at Smarte Carte in the baggage claim area in the main terminal of Seattle Airport. Smarte Carte also has copying and postal services and travel convenience items for sale.
  • Those who are a little lost and need some help or advice on airport facilities can find airport volunteers throughout Seattle Airport. The volunteers can point the way to things like restaurants and stores but do not escort passengers to connecting flights.
  • If you’re looking for things to do at Seattle Airport after your flight from London to Seattle, you can go on an art walk through the terminal. To find out information on the individual pieces of art, you can download the STQRY app by following links to the airport website.

Prefer to fly direct from London to Seattle/Tacoma Intl?

 
Find which airlines fly direct from London to Seattle/Tacoma Intl Airport, which days they fly and book direct flights.

Direct departures

London to Seattle/Tacoma Intl

Monday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Tuesday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Wednesday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Thursday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Friday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Saturday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Sunday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

See more direct flights

Direct returns

Seattle/Tacoma Intl to London

Monday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Tuesday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Wednesday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Thursday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Friday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Saturday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

Sunday

Alaska Airlines,British Airways,Delta

Alaska Airlines,British Airways, +1 more

See more direct flights

More options for your flight from London to Seattle

Complete your trip to Seattle with a hotel stay or car hire