SEA - LHR

£213 Find Cheap Flights from Seattle to London Heathrow Airport – Compare and Save

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 3/1. 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, 0 bags

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Everything you should know

Cheapest return fare
£479
Typical prices: £468-£725
Icelandair
Sat 12/9Mon 21/9
SEA - LHR • 1 stop
Cheapest direct flights
£610
Typical prices: £442-£664
Alaska Airlines, British Airways
Tue 20/10Wed 18/11
SEA - LHR • Direct
Advice from real travellers
AI-powered summary based on content written by travel experts and KAYAK users. AI can make mistakes.
KLM Premium Comfort adds SkyPriority security and two checked bags on long-haul.
BA premium economy adds legroom; Virgin Atlantic Economy Delight adds priority.
Expert advice
Expert advice
+1
+1
Expert advice
Expert advice
+1
Top airlines
Cheapest • from £479 (return)
Best reviews • 7.5 score
Airline reviews
Airline reviews
+1
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Airline reviews
Airline reviews
+1
Direct flights
You can fly direct with Alaska Airlines, British Airways, and others. Average duration is 9h 25m
Direct flights
Direct flights
+1
+1
Direct flights
Direct flights
+1
Avoid delays
Most punctual • 94% on-time
Best time • Fewest delays
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travellers who book at least 3 weeks in advance save around 29% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 24% price drop
Most popular
Good to know
Good to know
+1
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Good to know
Good to know
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KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to Heathrow!
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Flight 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

Sat, 12 Sep - Mon, 21 Sep
Icelandair Logo
23:25 - 11:55
SEA
-
LHR
28h 30m
1 stop
Icelandair Logo
21:25 - 20:40
LHR
-
SEA
31h 15m
1 stop
£479Icelandair
Fri, 11 Sep - Thu, 24 Sep
Icelandair Logo
19:00 - 20:20
SEA
-
LHR
17h 20m
1 stop
Icelandair Logo
13:05 - 20:40
LHR
-
SEA
15h 35m
1 stop
£480Icelandair
Sat, 12 Sep - Wed, 23 Sep
Icelandair Logo
23:25 - 11:55
SEA
-
LHR
28h 30m
1 stop
Icelandair Logo
21:25 - 17:55
LHR
-
SEA
28h 30m
1 stop
£481Icelandair
Tue, 17 Nov - Thu, 3 Dec
Multiple Airlines Logo
07:48 - 08:05
SEA
-
LHR
16h 17m
2 stops
Multiple Airlines Logo
12:15 - 17:00
LHR
-
SEA
12h 45m
1 stop
£482Multiple Airlines
Fri, 2 Oct - Sun, 4 Oct
Scandinavian Airlines Logo
15:55 - 18:30
SEA
-
LHR
18h 35m
2 stops
Scandinavian Airlines Logo
10:20 - 23:20
LHR
-
SEA
21h 00m
2 stops
£482Scandinavian Airlines
Tue, 20 Oct - Thu, 19 Nov
Multiple Airlines Logo
08:00 - 08:05
SEA
-
LHR
16h 05m
2 stops
Multiple Airlines Logo
12:15 - 17:00
LHR
-
SEA
12h 45m
1 stop
£483Multiple Airlines
Tue, 29 Sep - Tue, 13 Oct
Multiple Airlines Logo
07:52 - 08:05
SEA
-
LHR
16h 13m
2 stops
Multiple Airlines Logo
13:05 - 17:55
LHR
-
SEA
12h 50m
1 stop
£484Multiple Airlines
Tue, 20 Oct - Fri, 30 Oct
Multiple Airlines Logo
08:00 - 08:05
SEA
-
LHR
16h 05m
2 stops
Multiple Airlines Logo
12:15 - 18:00
LHR
-
SEA
12h 45m
1 stop
£485Multiple Airlines
Wed, 9 Dec - Tue, 22 Dec
Icelandair Logo
14:35 - 19:30
SEA
-
LHR
20h 55m
1 stop
Icelandair Logo
20:35 - 17:00
LHR
-
SEA
28h 25m
1 stop
£485Icelandair
Tue, 20 Oct - Sat, 31 Oct
Multiple Airlines Logo
08:00 - 08:05
SEA
-
LHR
16h 05m
2 stops
Multiple Airlines Logo
20:35 - 18:00
LHR
-
SEA
28h 25m
1 stop
£486Multiple Airlines
Booking Insights

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.

How much is a return flight from Seattle to London Heathrow Airport?

This analysis is based on the cheapest return trip price found on KAYAK in the last 12 months by searching for a flight from Seattle to London Heathrow Airport departing in September.

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 Friday is the most expensive. Flying from London Heathrow Airport back to Seattle, the best deals are generally found on Thursday, 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 January, where tickets cost £477 (return) on average. On the other hand, the most expensive months are June and July, where the average cost of round-trip tickets is £927 and £761 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.

Yes, flying with a stopover may cost you more time, but you can also save money on the route, with a 1 stop stopover the cheapest option at £688 on average.

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 3 weeks before departure, which saves you about 29% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 5 weeks before departure.

Expert advice

Expert advice for your flight from Seattle to Heathrow

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Blane Bachelor

Blane Bachelor

Expert on KLM and Air France

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.

Gabriel Leigh

Gabriel Leigh

Expert on Finnair

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.

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.

Duncan Madden

Duncan Madden

Expert on British Airways

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.

Kirstie Pickering

Kirstie Pickering

Expert on LHR

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.

Harriet Baskas

Harriet Baskas

Expert on 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, 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.

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

Low season

January

Cheapest flight

£213
Best time to beat the crowds (25% less expensive on average)
Most popular time to fly and prices are also 10% 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 
MichaelFlew with Delta
SEA
-
LHR
May 2026
We like Delta, Alaska and American. Be prepared for a bit of a trek from your arrival gate to Customs and outside services. Heathrow doesn't rank high on my list of major airports.
Verified travelerFlew with American Airlines
SEA
-
LHR
Apr 2026
Heathrow is too gigantic to have less than 2 hours of layover time.
Verified travelerFlew with British Airways
SEA
-
LHR
Apr 2025
Make sure you have plenty of time between flights if you are delayed.
Verified travelerFlew with British Airways
SEA
-
LHR
Feb 2025
Don’t take a flight if you sick, or if you have no choice prepare to stay covered with mask throughout the flight
Verified travelerFlew with British Airways
SEA
-
LHR
Apr 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 5 days, the lowest price for a flight from Seattle to London Heathrow Airport was £213 for a one-way ticket and £479 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: Virgin Atlantic, KLM, Delta, Air France, American Airlines, and JetBlue.

  • 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 oneworld 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 British Airways?

    The two airlines most popular with KAYAK users for flights from Seattle to London are Virgin Atlantic and British Airways. With an average price for the route of £586 and an overall rating of 7.5, Virgin Atlantic is the most popular choice. British Airways is also a great choice for the route, with an average price of £680 and an overall rating of 6.7.

  • 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 £260 or less one-way and £730 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

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

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

Reviews of the top 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.
7.5
Virgin AtlanticOverall score based on 693 reviews
7.5Entertainment
7.7Boarding
6.9Food
7.3Comfort
8.1Crew
Airline reviews

Great staff great experience, made a 2 hour delay very bearable

10.0 ExcellentAnonymous, Oct 2025
LAX - LHR
Read more Virgin Atlantic reviews

Great staff great experience, made a 2 hour delay very bearable

I was my pleasure to fly virgin on my birthday for my first solo trip ever 🫶🏼

Overall, flight was excellent but check in was very slow for Premium Economy. Economy queue was shorter but we weren't allowed to use it.

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.

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.

The crew was very good. However, the equipment was a bit dated. Some of the electronics were not working. To top it, three bags didn’t arrive with me. Two of them were delivered a day later. I’m still waiting for the third bag, I was so looking forward to this virgin Atlantic flight, but, I am disappointed.

My only complaint is that the pocket in front of me was ripped and my things, like iPad and airline magazines, kept slipping to the floor.

Flight delayed yet again. Crew apathetic and unhelpful re affect on connecting flight.

i saved my points for more than 10 years in anticipation of treating myself to an upper class fight to and from london on virgin atlantic. i was shocked to find what you consider “upper class” on the dreamliner. it was, at best, a mediocre business class accommodation. it was tight and not that comfortable, with nearly no personal storage. everything was cramped and just generally disappointing. once i lucked into a 1st class upgrade to europe on lufthansa - a magical experience that found me reluctant to sleep, lest i deprive myself the joy of their setup. i expected something similar from virgin atlantic, but i could not have been more wrong. it will be the same arrangement on my flight home, but at least i know what (not) to expect. to be clear, this is only in reaction to the physical accommodations. your people were, and always are fantastic.

Meh. Lived the seat. The entertainment unit did not work and had to be reset 3 times. Service was SLOW taking over 90 min to be served. Crew forgot about my meal. Chicken was dry and almost inedible.

Flying on the Boeing 787 from Seattle to London was everything that I expected. Every thing was great.

Moved me away from my family and refused to fix it.

Connection at Hethrow was horrible..We couldn't get out of the plane for an hour as they were buying people to the airport and there were not enough busses. We had 2 and half hf between flights so it was very tight. After departing plane we had to go thru security again. People with less time in between connections missed their flights

Captain sick. Unable to get replacement so delayed me 30 hours, many others delayed 54 hours. TOTALLY DESTROYED ALL MY PLANS, including lost my rental car which would now cost over 5 times what I paid so stuck with buses n trains... lost hotel reservations.... HORRIBLE!!!

The BA business class cabin is excellent,very comfortable for sleeping but the service could be improved.

The flight from Seattle was delayed, which made me miss my connection to Florence. I was re-booked NINE HOURS LATER!!! That’s basically a vacation day lost. British Airways needs to partner with other airlines when possible to get a more realistic travel time, if delays occur. I realize there aren’t many flights to Florence from London, so I would book differently were I to return. The actual flight from Seattle was very comfortable and the crew was great, no faults there. I enjoy British Airways, this was an anomaly.

Could have done with a 2nd round of drinks even if it was only to distribute bottled water

The second leg of my flight unexpectedly got canceled. I was stuck at the airport for the whole day and instead of flying out that morning I flew out in the evening. For some of my fellow passengers it was the second cancellation and their original flight was supposed to go out the day before. There was no reason given though getting rebooked was quick even though I would have preferred if I would have been on one of the earlier flights that day. Compensation was a £10 voucher for some food at the airport. I eventually arrived without further incident but but due to the cancellation, it was one of my more frustrating travels of my life.

Due to a cyber attack at the SeaTac airport ALL of the airport computers at the airport were down. This seriously impacted every airline at the airport and the resulted in our flight leaving a hour later than scheduled. This delay caused us to miss our connecting flight from Heathrow to Edinburgh. I was amazed to have British Airways staff meet us at the gate as we left our flight. They quickly provided us with new boarding passes for a flight going to Edinburgh later the same day. Problems sometimes happen but they handled the situation in first class style.

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

Information on your arrival and departure airports