LHR - SEA

$511 Find Cheap Flights from London Heathrow Airport to Seattle - Compare and Save

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Everything you should know

Cheapest round-trip
$581
Typical prices: $694-$942
Alaska Airlines
Thu 10/4Sun 10/14
LHR - SEA • Non-stop
Cheapest non-stop
$581
Typical prices: $709-$953
Alaska Airlines
Sat 9/29Mon 10/8
LHR - SEA • Non-stop
Nonstop flights
You can fly direct with British Airways, Delta and others. Average duration is 10h 08m.
Direct flights
+1
Direct flights
+1
Avoid delays
Most punctual • 96% on-time
Best time • Fewest delays
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 15 weeks in advance save around 23% compared to booking last minute.
Insights
Insights
When to travel
Cheapest • 20% price drop
Most popular
Good to know
+1
Good to know
+1
Top layover airports
Cheapest • Avg $645 (round-trip)
Shortest trip • 12h 06m (one-way)
Insights
Insights
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Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from Heathrow to Seattle (LHR-SEA)

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

Recent round-trip flight deals from Heathrow to Seattle

Sat, Sep 26 - Thu, Oct 22
Air Canada Logo
2:05 pm - 10:47 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
16h 42m2 stops Montreal Pierre Elliott Trudeau Intl Vancouver Intl
Air Canada Logo
10:50 am - 1:20 pmSEA  Seattle/Tacoma Intl-LHR London Heathrow
18h 30m1 stop Vancouver Intl
$584Air Canada
Sat, Dec 12 - Wed, Jan 13
Air Canada Logo
1:00 pm - 2:37 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
33h 37m2 stops Montreal Pierre Elliott Trudeau Intl Vancouver Intl
Air Canada Logo
7:05 pm - 9:20 amSEA  Seattle/Tacoma Intl-LHR London Heathrow
30h 15m2 stops Vancouver Intl Calgary
$585Air Canada
Sat, Dec 12 - Wed, Jan 13
Delta Logo
10:45 am - 6:53 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
16h 08m1 stop Salt Lake City
Delta Logo
4:55 pm - 10:40 amSEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 45mnonstop
$586Delta
Sat, Dec 12 - Sat, Feb 6
Delta Logo
9:50 am - 8:49 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
18h 59m1 stop Minneapolis St Paul
Delta Logo
4:55 pm - 10:40 amSEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 45mnonstop
$587Delta
Sat, Oct 3 - Thu, Oct 8
Icelandair Logo
9:25 pm - 8:40 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
31h 15m1 stop Reykjavik Keflavik Intl
Icelandair Logo
7:00 pm - 11:55 amSEA  Seattle/Tacoma Intl-LHR London Heathrow
32h 55m1 stop Reykjavik Keflavik Intl
$587Icelandair
Tue, Dec 15 - Sun, Dec 20
Alaska Airlines Logo
2:45 pm - 4:50 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 05mnonstop
Alaska Airlines Logo
6:55 pm - 12:20 pmSEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 25mnonstop
$590Alaska Airlines
Tue, Dec 15 - Sun, Dec 20
Alaska Airlines Logo
2:45 pm - 4:50 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 05mnonstop
Alaska Airlines Logo
6:55 pm - 12:20 pmSEA  Seattle/Tacoma Intl-LHR London Heathrow
9h 25mnonstop
$591Alaska Airlines
Sat, Oct 24 - Sat, Oct 31
KLM Logo
5:45 pm - 8:14 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 29mnonstop
KLM Logo
3:25 pm - 10:45 amSEA  Seattle/Tacoma Intl-LHR London Heathrow
12h 20m1 stop Amsterdam Schiphol
$597KLM
Sun, Oct 4 - Thu, Oct 22
KLM Logo
6:30 pm - 8:55 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
10h 25mnonstop
KLM Logo
5:45 pm - 1:50 pmSEA  Seattle/Tacoma Intl-LHR London Heathrow
12h 05m1 stop Amsterdam Schiphol
$602KLM
Thu, Oct 1 - Tue, Dec 22
Icelandair Logo
9:25 pm - 8:40 pmLHR  London Heathrow-SEA Seattle/Tacoma Intl
31h 15m1 stop Reykjavik Keflavik Intl
Icelandair Logo
2:35 pm - 10:50 amSEA  Seattle/Tacoma Intl-LHR London Heathrow
12h 15m1 stop Reykjavik Keflavik Intl
$606Icelandair
Booking Insights

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

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

How much is a round-trip flight from London Heathrow Airport to Seattle?

Round-trip flights from London Heathrow Airport to Seattle start at $581. Prices are below average for this route right now, with typical round-trip fares ranging from $694 to $942. The lowest price found in the past 5 days was $581 on Alaska Airlines.

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

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

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

  • February is the cheapest month to fly from London Heathrow Airport to Seattle at $651 round-trip.
  • July ($864) and June ($864) are the most expensive months.
  • The price difference between flying in the cheapest and most expensive months is 32% on average.
This is based on KAYAK aggregated and averaged internal data over the past 12 months.

When are prices from London Heathrow Airport to Seattle the cheapest?

Flights from London Heathrow Airport to Seattle are cheapest 15 weeks before departure. Booking in this window typically costs about 23% less than the average last-minute fare (within 2 weeks of the flight), based on KAYAK data.

Expert advice

Expert advice for your flight from Heathrow to Seattle

 
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Marisa Garcia

Marisa Garcia

Expert on Iberia

Marisa knows planes inside and out, spending 16 years working on aircraft in hangars at airports around the world. She is an aviation industry expert, specialized in airline interiors and regulations. Ten years ago, she pivoted to journalism. She shares her insights in leading aviation, travel, and business publications and on her site FlightChic.

Duncan Madden

Duncan Madden

Expert on British Airways and LHR

Duncan is a freelance travel writer, copywriter and book author in constant search of travel stories and the perpetual sensation of being on holiday. He’s never happier than when on a dusty trail in search of empty waves or ducking under the piste tape in search of snowbound solitude. British born, living in Germany, but happiest heading for the horizon. His first book, Found in Translation, explores the etymologies and stories of country names around the world and is out now.

Stefanie Waldek

Stefanie Waldek

Expert on Delta

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Laura Ratliff

Laura Ratliff

Expert on Virgin Atlantic

Laura Ratliff is a New York-based writer and editor. She lives in downtown Brooklyn with her husband and their beloved dogs. Originally from Texas, she now considers New York City her home. She typically spends more than 200,000 miles on a plane each year and stays in plenty of hotels.

Harriet Baskas

Harriet Baskas

Expert on American Airlines and SEA

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Key details for London Heathrow Airport to Seattle flights

Low season

February

Cheapest flight

$511
Best time to beat the crowds with an average 20% drop in price.
Most popular time to fly with an average 7% increase in price.
Flight from London Heathrow Airport to Seattle

When to book flights from Heathrow to Seattle

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

Your London Heathrow Airport to Seattle flight questions, answered

Find helpful route details based on KAYAK data, including flight times, airports, airlines and booking questions.

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

    Among airlines operating London Heathrow Airport to Seattle flights:

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

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

  • What airlines are available from London Heathrow Airport to Seattle?

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

    • British Airways
    • Delta
    • Alaska Airlines
    • Virgin Atlantic

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

    Flights from London Heathrow Airport to Seattle usually depart from London Heathrow (LHR) and arrive at Seattle/Tacoma Intl (SEA).

  • Which airlines include bags at no extra cost on London Heathrow Airport 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

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

  • What cabin classes can I book on flights from London Heathrow Airport to Seattle?

    Four cabin classes are available on flights from London Heathrow Airport to Seattle:

    • Economy Class
    • Premium Economy Class
    • Business Class
    • First Class

    Prices vary by airline.

  • How much can I save by taking a layover when flying from London Heathrow Airport to Seattle?

    On this route, layover flights are cheaper than nonstop options on average. Layover fares average $645 round-trip via Munich Franz Josef Strauss (MUC), compared to $826 for nonstop.

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

    There is no standard. Checked-bag policies vary by airline on this route. Most carriers charge $51–$100 for the first checked bag in economy. Premium fares and elite-status bookings typically include a free checked bag.

  • Which aircraft model is used most often on flights from London Heathrow Airport to Seattle?

    The Boeing 787-10 Dreamliner family is used most often on this route, operated mainly by British Airways and Finnair. Other aircraft seen on the route include Airbus A330-900neo variants.

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

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

    • Reykjavik Keflavik Intl (KEF) - 58% of one-stop connections
    • Dublin (DUB) - 25% of one-stop connections
    • Kastrup Copenhagen (CPH) - 6% of one-stop connections
    • Chicago O'Hare Intl (ORD) - 2% of one-stop connections

    Reykjavik Keflavik Intl (KEF) handles the largest share of one-stop connections on this route.

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

    Yes. Being flexible with your travel dates can save you up to 10% on the London Heathrow Airport to Seattle route. Wednesday is the cheapest departure day at $783 round-trip on average, while Sunday is the most expensive at $865, a difference of $82. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

  • At what point is a flight considered delayed from London Heathrow Airport 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 Heathrow Airport to Seattle route, 11% of flights were delayed in the past 3 months, with delays averaging 2 hours 17 minutes.

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

    Afternoon is the busiest departure period on London Heathrow Airport to Seattle flights, with 50% of flights leaving in that window. Morning departures account for 25%, evening flights for 25%, and night flights for 0%.

  • What popular places can I visit in Seattle?

    Some of the most popular sights in Seattle are Pike Place Market, Pier 66 and Lumen Field. These are among the most viewed places in Seattle on KAYAK.

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

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

    • Earliest: departs at 9:25 am and lands at 7:33 pm
    • Latest: departs at 6:30 pm and lands at 4:38 am.

    The flight takes about 10h 08m.

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

    Last-minute fares on this route - booked within 2 weeks of departure - run 19% above the route average of $810. Book 15 weeks before departure for the lowest fares.

  • How long is a flight from London Heathrow Airport to Seattle?

    A nonstop flight from London Heathrow Airport to Seattle takes 10h 08m, covering 4,783 miles.

  • Do I need a passport to fly from London Heathrow Airport 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 are flight prices from London Heathrow Airport to Seattle looking right now?

    One-way fares from London Heathrow Airport to Seattle are currently lower than usual. Average one-way flight prices are about $513, which is 28% below the typical average for this route.

  • How does Delta’s on-time performance compare to other airlines on London Heathrow Airport to Seattle flights?

    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 Heathrow Airport to Seattle flights are:

    • Delta: 96% on time
    • Virgin Atlantic: 90% on time
    • British Airways: 86% on time

    Overall, flights on this route are on time 89% of the time on average.

  • How do delay rates compare for morning and evening flights from London Heathrow Airport to Seattle?

    Evening flights have the fewest delays on this route. Delays tend to pile up throughout the day as one late flight pushes the next, so earlier departures are usually more reliable.

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

    Flying via Amsterdam Schiphol (AMS) gives the shortest average 1-stop total travel time at 12h 06m, compared with 12h 58m via Paris Charles de Gaulle (CDG) and 13h 19m via Calgary (YYC).

  • What is the time difference between London Heathrow Airport and Seattle?

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

  • What car rental options are available at Seattle/Tacoma Intl Airport (SEA)?

    Seattle/Tacoma Intl Airport (SEA) hosts 5 major car rental companies, with daily rates starting from around $4 for economy cars. Top options include:
    • Fox
    • Europcar
    • Thrifty
    • Budget
    • Dollar

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

    Round-trip flights from London Heathrow Airport to Seattle range from $694 to $942, with an average of $810 over the past 12 months. Anything below $694 counts as a good deal.

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

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

    • • Virgin Atlantic
    • • Air France
    • • KLM
    • • Delta

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

Your guide to booking London Heathrow Airport to Seattle flights

Get tips on when to book, when to fly and what to know before your trip.
  • If your dates can be flexible, aim for a Wednesday departure instead of Sunday. On this route, Wednesday flights average $783 - about $82 less than Sunday (9% 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 23% versus last-minute pricing (KAYAK booking data, last 12 months).
  • If you can choose when to travel, plan your London Heathrow Airport to Seattle trip for February. Fares historically average $651 round-trip in that month - typically $213 less than the most expensive month, which is June (based on the last 12 months).
  • If arriving on time is high on your priority list, Delta is the strongest pick on this route. 96% of Delta flights from London Heathrow Airport to Seattle arrived on time in the past 3 months, slightly above the route's average on-time arrival rate of 89%. When flights on this route do arrive late, the average delay is 2 hours 17 minutes, so choosing a carrier with strong on-time performance can make a difference on tight schedules.
  • If you have the time, taking a 1-stop flight through Munich Franz Josef Strauss Airport (MUC) can be cheaper than flying direct. The cheapest layover option averages $645 round-trip on this route - about $181 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.
    - Seattle Airport Marriott
    - Coast Gateway Hotel
    - Fairfield by Marriott Inn & Suites Seattle Sea-Tac Airport

Prefer to fly direct from London Heathrow Airport to Seattle?

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

Direct departures

London Heathrow to Seattle/Tacoma Intl

Monday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Tuesday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Wednesday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Thursday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Friday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Saturday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Sunday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

See more direct flights

Direct returns

Seattle/Tacoma Intl to London Heathrow

Monday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Tuesday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Wednesday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Thursday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Friday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Saturday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

Sunday

Alaska Airlines,British Airways,Delta, +1 more

Alaska Airlines,British Airways, +2 more

See more direct flights

More options for your flight from Heathrow to Seattle

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