SEA - LHR

£122 Find Cheap Flights from Seattle to London Heathrow Airport

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Seattle to Heathrow departing on 5/10. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to London Heathrow Airport

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to London, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to London, as well as popular online travel agencies
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Flights Deals

Cheap Flights from Seattle to Heathrow (SEA-LHR)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for return flights from Seattle to Heathrow that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent return flight deals from Seattle to Heathrow

Sun, 12 Oct - Fri, 17 Oct
Scandinavian Airlines Logo
16:20 - 21:40SEA-LHR
21h 20m1 stop
Scandinavian Airlines Logo
06:40 - 14:00LHR-SEA
15h 20m1 stop
£314Scandinavian Airlines
Find Deal
Sun, 5 Oct - Sat, 18 Oct
Scandinavian Airlines Logo
16:20 - 21:40SEA-LHR
21h 20m1 stop
Scandinavian Airlines Logo
15:35 - 14:00LHR-SEA
30h 25m2 stops
£317Scandinavian Airlines
Find Deal
Sun, 9 Nov - Wed, 19 Nov
Aer Lingus Logo
20:05 - 19:50SEA-LHR
15h 45m1 stop
Aer Lingus Logo
09:50 - 18:20LHR-SEA
16h 30m1 stop
£347Aer Lingus
Find Deal
Mon, 25 Aug - Fri, 5 Sep
Aer Lingus Logo
19:35 - 15:55SEA-LHR
12h 20m1 stop
Aer Lingus Logo
13:25 - 17:50LHR-SEA
12h 25m1 stop
£350Aer Lingus
Find Deal
Mon, 6 Oct - Mon, 20 Oct
Icelandair Logo
19:00 - 11:55SEA-LHR
32h 55m1 stop
Icelandair Logo
21:25 - 17:50LHR-SEA
28h 25m1 stop
£357Icelandair
Find Deal
Fri, 12 Sep - Tue, 14 Oct
Icelandair Logo
15:45 - 11:55SEA-LHR
12h 10m1 stop
Icelandair Logo
21:25 - 20:40LHR-SEA
31h 15m1 stop
£360Icelandair
Find Deal
Tue, 5 Aug - Tue, 12 Aug
Virgin Atlantic Logo
17:35 - 11:20SEA-LHR
9h 45mdirect
Virgin Atlantic Logo
06:15 - 11:15LHR-SEA
13h 00m1 stop
£364Virgin Atlantic
Find Deal
Wed, 20 Aug - Wed, 27 Aug
Virgin Atlantic Logo
17:35 - 11:20SEA-LHR
9h 45mdirect
Virgin Atlantic Logo
19:45 - 11:15LHR-SEA
23h 30m1 stop
£366Virgin Atlantic
Find Deal
Wed, 13 Aug - Wed, 27 Aug
British Airways Logo
13:30 - 06:50SEA-LHR
9h 20mdirect
British Airways Logo
09:50 - 11:35LHR-SEA
9h 45mdirect
£369British Airways
Find Deal
Wed, 1 Oct - Tue, 14 Oct
British Airways Logo
13:30 - 06:50SEA-LHR
9h 20mdirect
British Airways Logo
09:25 - 11:10LHR-SEA
9h 45mdirect
£378British Airways
Find Deal
Expert advice

Expert advice for your flight from Seattle to Heathrow

 
Snippets provided in this section are AI-generated based on a summarisation of KAYAK-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Airlines
KLM

Premium Comfort offers SkyPriority security and two checked bags, ideal for long-haul flights.


World Business Class features lay-flat seats with direct aisle access for comfort.

Read more about KLMby Blane Bachelor
Air France

Air France Premium offers SkyPriority benefits and meals by celebrity chefs on long-haul flights.


Economy includes complimentary champagne and personal entertainment screens for a luxe touch.

Finnair

Finnair's A350 offers lower cabin altitude and higher humidity for a better arrival feeling.


Economy Comfort offers extra legroom for a small charge, enhancing long-haul comfort.

Read more about Finnairby Gabriel Leigh
Virgin Atlantic

Economy Delight offers priority check-in and boarding, plus extra legroom for comfort.


Upper Class provides fully flat beds and access to exclusive lounges at Heathrow.

British Airways

Upgrade to premium economy for 18 cm extra legroom, wider seats, and priority boarding.


Check plane type for legroom: 79 cm on most, but 74 cm on A321neo planes.

Airports
SEA

Use the SEA Spot Saver for free expedited security screening. Book online or via the flySEA app for Checkpoints 2, 3, and 5.

Read more about SEAby Harriet Baskas
LHR

Take the Heathrow Express for a quick 15-minute ride to London Paddington. Book tickets in advance for the best rates.

Read more about LHRby Kirstie Pickering
Our travel experts
Blane Bachelor

Blane Bachelor

Expert on KLM and Air France

Blane Bachelor

Blane Bachelor

Blane Bachelor is a journalist and editor specialising in travel and aviation who writes regularly for top global outlets. Born and raised in Florida, Blane has worked and lived in four countries, including the Netherlands, where she’s currently based with her family. Her favourite way to get to know a new destination is by running or riding a bike around town – or hearing a spooky ghost story about local history.

Read more
Gabriel Leigh

Gabriel Leigh

Expert on Finnair

Gabriel Leigh

Gabriel Leigh

Gabriel is a writer and video creator. As senior content producer for Flightradar24 and Monocle’s transport correspondent, he keeps a close eye on aviation in particular. He has also written travel articles for the likes of The New York Times. Born in New York but raised around the world, he now lives in Sweden. He’s been to 75 countries, flying 2.3 million miles on 113 airlines and through 234 airports in the process.

Read more
Laura Ratliff

Laura Ratliff

Expert on Virgin Atlantic

Laura Ratliff

Laura Ratliff

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.

Read more
Duncan Madden

Duncan Madden

Expert on British Airways

Duncan Madden

Duncan Madden

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.

Read more
Kirstie Pickering

Kirstie Pickering

Expert on LHR

Kirstie Pickering

Kirstie Pickering

Aviation and business journalist Kirstie didn’t leave England until she was 18 years old, but has since travelled to over 20 countries including Japan, Canada, and Iceland. Her travel expertise lies in European city breaks, including how to find the best locally-owned hotels and restaurants and how to optimise the airport experience for your needs.

Read more
Harriet Baskas

Harriet Baskas

Expert on SEA

Harriet Baskas

Harriet Baskas

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, 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.

Read more
Useful Info

KAYAK's insights & trends for Seattle to Heathrow flights

Get data-powered insights and trends into flights from Seattle to Heathrow to help you find the cheapest flights, the best time to fly and much more.

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

The average price of all round-trip flights from Seattle to London Heathrow Airport clicked on KAYAK for each day over the last 12 months.

For Seattle to London Heathrow Airport, Tuesday is the cheapest day to fly on average and Thursday is the most expensive. Flying from London Heathrow Airport back to Seattle, the best deals are generally found on Tuesday, with Sunday being the most expensive.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Seattle to London Heathrow Airport, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Seattle to London Heathrow Airport is March, where tickets cost £503 (return) on average. On the other hand, the most expensive months are June and July, where the average cost of round-trip tickets is £823 and £748 respectively.

Can I save money by flying with a stopover from Seattle to London Heathrow Airport?

The average return price for all direct flights, flights with one stopover, and flights with two stopovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of £1,541, prices are generally cheapest when you fly direct.

How far in advance should I book a flight from Seattle to London Heathrow Airport?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Seattle to London Heathrow Airport, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Seattle to London Heathrow Airport, you should book around 5 weeks before departure. For the absolute cheapest price, our data suggests you should book 9 weeks before departure.


Good to know - Cheap tickets from Seattle to London Heathrow Airport

Low seasonJanuary
High seasonAugust
Cheapest flight£122
Best time to beat the crowds (11% less expensive on average)
Most popular time to fly and prices are also 1% lower on average.
Flight from Seattle to London Heathrow Airport

When to book flights from Seattle to Heathrow

Are your dates flexible? Find out the best times to travel from Seattle to Heathrow based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated return price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or returns with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

Flights from Seattle to Heathrow: the best tips from KAYAK users' own experiences

Insights shared by verified travellers who flew the route from Seattle to Heathrow 
Verified travelerFlew with British AirwaysSEA-LHRApr 2025
Make sure you have plenty of time between flights if you are delayed.
Verified travelerFlew with British AirwaysSEA-LHRApr 2024
Bring a sack lunch -- airport food was very expensive.

FAQs for booking Seattle to London Heathrow Airport flights

  • What is the cheapest flight from Seattle to London Heathrow Airport?

    In the last 3 days, the lowest price for a flight from Seattle to London Heathrow Airport was £166 for a one-way ticket and £427 for a return.

  • Which airports will I be using when flying from Seattle to London Heathrow Airport?

    Seattle airport is called Seattle/Tacoma Intl and the only airport in London Heathrow Airport is London Heathrow.

  • Which airlines offer Wi-Fi service onboard planes from Seattle to London Heathrow Airport?

    All the following airlines offer inflight Wi-Fi service on the Seattle to London Heathrow Airport flight route: Air France, Delta, Virgin Atlantic, American Airlines, KLM, and Lufthansa.

  • Which aircraft models fly most regularly from Seattle to London Heathrow Airport?

    The Boeing 787-10 Dreamliner is the aircraft model that flies most regularly on the Seattle to London Heathrow Airport flight route.

  • Which airline alliances offer flights from Seattle to London Heathrow Airport?

    oneworld, and SkyTeam are the airline alliances operating flights between Seattle and London Heathrow Airport, with SkyTeam being the most commonly used for this route.

  • On which days can I fly direct from Seattle to London Heathrow Airport?

    There are direct flights from Seattle to London Heathrow Airport on a daily basis.

  • Which is the best airline for flights from Seattle to London, Virgin Atlantic or Icelandair?

    The two airlines most popular with KAYAK users for flights from Seattle to London are Virgin Atlantic and Icelandair. With an average price for the route of £635 and an overall rating of 7.4, Virgin Atlantic is the most popular choice. Icelandair is also a great choice for the route, with an average price of £563 and an overall rating of 7.0.

  • How does KAYAK find such low prices on flights from Seattle to London Heathrow Airport?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Seattle to London Heathrow Airport.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Seattle to London Heathrow Airport?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London Heathrow Airport from Seattle is likely to change within 7 days, so travellers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Seattle to London Heathrow Airport?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional return ticket. You could then fly to London Heathrow Airport with an airline and back to Seattle with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Seattle to London Heathrow Airport?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to London Heathrow Airport from Seattle up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Seattle to London Heathrow Airport

  • Looking for a cheap flight from London Heathrow Airport to Seattle? 25% of our users found flights on this route for £368 or less one-way and £453 or less round-trip.

Prefer to fly direct from Seattle to London Heathrow Airport?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Seattle/Tacoma Intl to London Heathrow.
Find which airlines fly direct from Seattle/Tacoma Intl Airport to London Heathrow Airport, which days they fly and book direct flights.

Direct departures

Seattle/Tacoma Intl to London Heathrow

Monday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Tuesday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Wednesday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Thursday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Friday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Saturday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Sunday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

See more direct flights

Direct returns

London Heathrow to Seattle/Tacoma Intl

Monday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Tuesday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Wednesday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Thursday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Friday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Saturday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

Sunday

Aer Lingus, Aeromexico, Air France, +9 more

Aer Lingus, Aeromexico, +10 more

See more direct flights

Reviews of the top 3 airlines flying from Seattle to Heathrow

 
See real verified KAYAK customer reviews for airlines flying from Seattle to London. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Seattle to Heathrow? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.4
Virgin AtlanticOverall score based on 653 reviews
7.5Entertainment
8.1Crew
7.2Comfort
6.9Food
7.6Boarding
Airline reviews

Premium economy more comfortable than economy, but not by much. Did was awful, do not try the omelette. Flight crew were helpful. Flight was delayed by over an hour. Overall but bad, arrived safely and thank God.

8.0 ExcellentAnonymous, Jul 2025LHR - LOS
Read more Virgin Atlantic reviews

Premium economy more comfortable than economy, but not by much. Did was awful, do not try the omelette. Flight crew were helpful. Flight was delayed by over an hour. Overall but bad, arrived safely and thank God.

Food was excellent. Service was very good. Staff was very helpful to all passengers.

The crew was excellent as ever on Virgin. The special meal was poor unfortunately. More significantly when we arrived at Manchester Airport there was no air bridge provided and we had to exit the plane down a rickety stair case. This is unacceptable for a transatlantic flight. Whilst I understand that this is the airport’s fault at the end of the day the airline is responsible for our transportation and needs to do something.

Super friendly and helpful staff, from check-in desk to cabin crew.

Following a paid seat upgrade for enhanced comfort, I encountered an unacceptable odor in my assigned area. It took three hours for the crew to relocate me, and the replacement seat was unacceptably close to the lavatory, offering no improvement.

Good overall. Cannot fault the airlines. I have had better entertainment systems before ie ice in Emirates but it was not too bad. Food was decent and staff were friendly.

I did not fly by vergin atlantic from bangalore to vasco da gama

Your flight delayed at Heathrow n I almost missed my mother funeral.you idiots. I had to waste 10 hours in different airports. Thank your stars I'm not suing you.

Miami airport needs more thorough signage. It was a long walk from my transport point to the check in desk,

Flight took off an hour late. Had to stay on the tarmac for half an hour after landing. Both annoying.

Good service. No complementary food for international flight. WiFi kinda pricey. Got the job done for the right price.

Still one of my favorite airlines, but the entertainment options were a bit lacking. It didn't help that my screen didn't work on one of the legs of the trip.

The plane was very small and the aisle was so narrow that every time someone walked by they rubbed against me, so it was very uncomfortable.

Everything was good. Only issue comes from being vegan and flying. The food options are super limited.

Overall good for an economy fare. IMO the movie selection could be improved. Great that you can now connect bluetooth headphones to the entertainment system.

Paid for a Premium seat...minimal recline, no footrest. Maybe slightly wider than a cheap economy seat. Zero chance of getting any rest on this plane

Comfort of seats is not good. Like sitting on a rock for 6 hours. Also no in flight food and limited beverages unless you pay is not nice. Need flight to be dark during the “night” but attendants don’t ask for shades to be lowered..

Seats in premier saga class were narrow and hard. Very uncomfortable for a 5-hour flight.

The seats on this airline are sooo small, even for a petite person. I felt like the seat tilted forward and I was fighting to stay in it. The lavatory is horribly small, with a wet floor because the sink is so small you can't help but splash the water all over when washing up.

For an economy lite experience, it's by far the best I've had. New planes, clean, great destinations. Very happy to have discovered Iceland Air.

Very crowded, no real explanation of food "chicken or pasta?" After dinner no drinks service. Plane was clean, but little help with finding soaces fir luggage to get into overhead bins. Many passengers putting 2 bags, hats, duty free in overhead bins so no space for roll ons

Flight was good but seat in 12D was not comfortable, better on the Airbus 321 from Tampa to Charlotte. No breakfast was served before landing in zLonfon only a coffee and orange juice.

I was transferred to an American Airlines flight. The boarding was late and unorganized. The seating was extremely tight and uncomfortable. Will not use AA again.

The entertainment selection was ok, but overall not bad! The crew was great.

Good crew and boarding process. Horrible food and one of the most uncomfortable aircraft seats I have ever sat in. The cabin temperature was warm which made it hard for my family to sleep.

The check-in of my luggage was terrible. When purchased my tickets, one luggage and one carry-on was part of the fight. My flight was switched from British to American Airline. During check-in of luggage at the airport, I was denied and had to pay extra $75. How do I get reimbursed for this extra luggage payment?

More Indian vegetarian food options would have been better Availability of seat selection free of charge 72 hours before departure would be great

This was the second time on BA, food terrible, bathrooms gross,( granted, that was mostly due to the disgusting children urinating all over it)boarding was late and disorganized. No gate issued until last minute st Heathrow, bad system, caused undue stress. Seats were painful, that's what you get for traveling like a poor in economy, right BA? Should have been able to afford business or first class if you want to actually be able to walk upright without back pain after a trip.

The flight was delayed twice and because of that, we missed our connecting flight. British Airways then attempted to put us on the last flight to Milan from London which would have kept us in the airport for 12 hours. We had to speak to several levels of bureaucracy until BA management let us fly on a flight that only kept us in the airport for two hours. If there was an earlier flight, why weren’t we put on that flight from the start? Unacceptable behavior from what was once my favorite carrier.

The payment system was not working so was unable to connect wifi the entire flight

Everything you need to know for your flight from Seattle to Heathrow

Information on your arrival and departure airports

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