SEA - LHR

C$ 538 Find Cheap Flights from Seattle to London

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 London departing on 11/1. 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

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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Everything you should know

Cheapest round-trip
C$ 779
Overall average: C$ 992
Icelandair
Sun 19/4Tue 28/4
SEA - LHR • 1 stop
Cheapest direct flights
C$ 815
Typical prices: C$ 1,136-C$ 2,106
Delta
Mon 1/12Fri 12/12
SEA - LHR • Direct
Our travellers' advice
AI-generated summary based on content written by travel experts and KAYAK users
Virgin's Economy Delight offers extra legroom and priority.
Pack a lunch as airport food can be costly.
Expert advice
Expert advice
+1
+1
Expert advice
Expert advice
+1
Top airlines
Icelandair
Cheapest • from C$ 779 (round-trip)
Virgin Atlantic
Best reviews • 7.5 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
2 weeks
in advance
Our data shows that travellers who book at least 2 weeks in advance save around 24% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 17% price drop
August
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to London!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from Seattle to London (SEA-LHR)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Seattle to London 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 round-trip flight deals from Seattle to London

Sun, 19 Apr - Tue, 28 Apr
Icelandair Logo
3:45 p.m. - 11:55 a.m.SEA-LHR
12h 10m1 stop
Icelandair Logo
1:05 p.m. - 5:50 p.m.LHR-SEA
12h 45m1 stop
C$ 779Icelandair
Find Deal
Sat, 4 Apr - Sat, 11 Apr
Icelandair Logo
7:00 p.m. - 11:55 a.m.SEA-LHR
32h 55m1 stop
Icelandair Logo
9:25 p.m. - 8:45 p.m.LHR-SEA
31h 20m1 stop
C$ 783Icelandair
Find Deal
Sat, 2 May - Mon, 11 May
Icelandair Logo
3:45 p.m. - 11:55 a.m.SEA-LHR
12h 10m1 stop
Icelandair Logo
1:05 p.m. - 8:45 p.m.LHR-SEA
15h 40m1 stop
C$ 799Icelandair
Find Deal
Mon, 1 Dec - Tue, 3 Feb
Multiple Airlines Logo
7:20 p.m. - 12:50 p.m.SEA-LHR
9h 30mdirect
Multiple Airlines Logo
6:20 a.m. - 11:25 a.m.LHR-SEA
13h 05m1 stop
C$ 806Multiple Airlines
Find Deal
Tue, 2 Dec - Thu, 11 Dec
Delta Logo
4:48 p.m. - 10:30 a.m.SEA-LHR
9h 42mdirect
Delta Logo
6:30 a.m. - 11:50 a.m.LHR-SEA
13h 20m1 stop
C$ 807Delta
Find Deal
Mon, 1 Dec - Wed, 10 Dec
Delta Logo
11:55 p.m. - 7:05 a.m.SEA-LHR
23h 10m1 stop
Delta Logo
6:20 a.m. - 1:25 p.m.LHR-SEA
15h 05m1 stop
C$ 811Delta
Find Deal
Mon, 1 Dec - Mon, 8 Dec
Delta Logo
11:55 p.m. - 7:05 a.m.SEA-LHR
23h 10m1 stop
Delta Logo
11:45 a.m. - 11:50 a.m.LHR-SEA
32h 05m1 stop
C$ 813Delta
Find Deal
Tue, 2 Dec - Thu, 11 Dec
Delta Logo
2:05 p.m. - 4:50 p.m.SEA-LHR
18h 45m1 stop
Delta Logo
6:30 a.m. - 11:50 a.m.LHR-SEA
13h 20m1 stop
C$ 814Delta
Find Deal
Mon, 1 Dec - Thu, 11 Dec
Delta Logo
4:48 p.m. - 10:30 a.m.SEA-LHR
9h 42mdirect
Delta Logo
2:45 p.m. - 4:50 p.m.LHR-SEA
10h 05mdirect
C$ 815Delta
Find Deal
Sun, 15 Feb - Thu, 26 Feb
Delta Logo
4:55 p.m. - 10:30 a.m.SEA-LHR
9h 35mdirect
Delta Logo
6:20 a.m. - 11:25 a.m.LHR-SEA
13h 05m1 stop
C$ 817Delta
Find Deal
Booking Insights

KAYAK's insights & trends for Seattle to London flights

Get data-powered insights and trends into flights from Seattle to London 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?

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.

If your flying dates are flexible, you should consider flying to London on a Sunday, as we generally find the cheapest rates on that day for this route. On the other hand, Wednesday is the most expensive day to fly from Seattle to London. For your return ticket, we recommend flying on a Monday and avoiding Sundays for the best deals.

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 October, where tickets cost C$ 926 (return) on average. On the other hand, the most expensive months are June and December, where the average cost of round-trip tickets is C$ 1,537 and C$ 1,477 respectively.

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

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of C$ 792, 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 2 weeks before departure, which saves you about 24% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 9 weeks before departure.

Expert advice

Expert advice for your flight from Seattle to London

 
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
Delta

Delta One offers lie-flat seats with privacy doors on select aircraft for enhanced comfort.


Delta's Wi-Fi is free for SkyMiles members on most planes, enhancing connectivity.

Virgin Atlantic

Virgin's Upper Class offers fully flat beds and exclusive lounge access for luxury travel.


Virgin's Economy Delight includes extra legroom and priority boarding for added comfort.

British Airways

BA's premium economy offers 18 cm extra legroom, ideal for long-haul comfort.


BA's Club World provides priority boarding and enhanced meal service for a premium experience.

Airports
SEA

Use the SEA Spot Saver for free expedited security screening. Book online or via the flySEA app for faster access.

LHR

Take the Elizabeth Line from Heathrow to central London for a cost-effective journey. It's half the price of the Express.

Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on Delta

Stefanie Waldek

Stefanie Waldek

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.

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 and LHR

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
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, 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.

Read more

Good to know

Low seasonJanuary
Cheapest flightC$ 538
Best time to beat the crowds (9% less expensive on average)
Most popular time to fly and prices are also 8% lower on average.
Flight from Seattle to London

When to book flights from Seattle to London

Are your dates flexible? Find out the best times to travel from Seattle to London based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips 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 London: the best tips from KAYAK users' own experiences

Insights shared by verified travellers who flew the route from Seattle to London 
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 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 C$ 538 for a one-way ticket and C$ 779 for a round-trip.

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

    Air France, Delta, Virgin Atlantic, KLM, and American Airlines offer inflight Wi-Fi service on the Seattle to London flight route.

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

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

  • Which airline alliances offer flights from Seattle to London?

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

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

    There are direct flights from Seattle to London 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 C$ 1,005 and an overall rating of 7.5, Virgin Atlantic is the most popular choice. Icelandair is also a great choice for the route, with an average price of C$ 773 and an overall rating of 7.1.

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

    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.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London 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?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to London 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?

    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 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? 25% of our users found flights on this route for C$ 482 or less one-way and C$ 958 or less round-trip.

Prefer to fly direct from Seattle to London?

 
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

British Airways,Delta,Virgin Atlantic

British Airways,Delta, +1 more

Tuesday

British Airways,Delta,Virgin Atlantic

British Airways,Delta, +1 more

Wednesday

British Airways,Delta

British Airways,Delta

Thursday

British Airways,Delta,Virgin Atlantic

British Airways,Delta, +1 more

Friday

British Airways,Delta

British Airways,Delta

Saturday

British Airways,Delta,Virgin Atlantic

British Airways,Delta, +1 more

Sunday

British Airways,Delta

British Airways,Delta

See more nonstop flights

Direct returns

London Heathrow to Seattle/Tacoma Intl

Monday

British Airways,Delta,Virgin Atlantic

British Airways,Delta, +1 more

Tuesday

British Airways,Delta,Virgin Atlantic

British Airways,Delta, +1 more

Wednesday

British Airways,Delta

British Airways,Delta

Thursday

British Airways,Delta,Virgin Atlantic

British Airways,Delta, +1 more

Friday

British Airways,Delta

British Airways,Delta

Saturday

British Airways,Delta,Virgin Atlantic

British Airways,Delta, +1 more

Sunday

British Airways,Delta

British Airways,Delta

See more nonstop flights

Reviews of the top 4 airlines flying from Seattle to London

 
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 London? 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 673 reviews
7.7Boarding
7.3Comfort
8.1Crew
6.9Food
7.5Entertainment
Airline reviews

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

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

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

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

Food was the worst I’ve had on a VA flight. Normally it’s a lot better

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

These are one of the older seat arrangements facing away from the windows! Not particularly convenient sets. No storage spaces. NO COAT HANGING HOOKS. Inconvenient business class seat compared to any other airlines of similar class. Staff are excellent! Extremely professional, friendly. Food is good too.

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.

The staff was not very polite but the flight was very very nice and comfortable and the entertainment was great

Great crew - old style upper class seats on the older fleet now feels dated

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.

Having been prepared for paying for everything on board other than water, coffee and tea the service was OK. Food and drink is expensive but the food was OK if limited in scope. Plane was clean and obviously well serviced. After complaining about having to walk in wind and rain to a get a bus to the airport the same thing happened at Portland. I’m sure you could get a terminal gate flight, complimentary food and drink for not much more money without traipsing through rain and slush in Reykjavik. Not bad but not great.

Iceland air transfer was bad. They lost my luggage and I just received it 11/1

It was too cold in the plane my feet froze

Handling our luggage was the biggest issue - they lost it and we got it almost 3 days later. Really threw off the beginning of our trip and we really had to change our itinerary accordingly.

Seat was hard and uncomfortable and the temperature too warm and uncomfortable.

I flew Icelandair with my partner from Prague to the US. Overall flight time was around 12 hours, with a connecting flight in Iceland. I have flown internationally for years and with multiple airlines. Every airline serves you a meal when traveling internationally. Icelandair not only did not offer an inclusive meal, but they did not even offer a snack. The only things they served over our long flight was water and coffee. Ridiculous! Never again will I fly with Icelandair.

It was good. The air plane is clean and staff were friendly.

Worst airline I’ve ever flown. Delayed 5.5 hrs, missed connecting flight, and missed an entire day of vacation. Zero customer service

Everything sucked. No food, one small glass of water, a tiny coffee, 5.5 hour delay with no customer service. Would never recommend flying them.

The crew was wonderful at check in, the gate and on board. Felt the luggage had more room than the passengers. The seats were smaller than most domestic U.S. airlines. I'm only 5'2" and I had little legroom. There were only 2 bathrooms in coach. Needed more. The flight was very smooth but not the most comfortable.

Suddenly, I don't find my flight back on the app Help Ticket 0757345716866 Hoeflich Flight back Sunday ib5333 Ib2629 Ib4268

Was all good.l including a sofdrink. AA improved significantly. There was no entertainment.

I've taken British Airways before and it has been great. On this trip to Spain and Portugal we had two BA flights. On both flights we were taken by bus from the terminal out to the plane on the tarmac. There were many older folks on these flights, and to ask people in their 70s to lug their carry-on and personal items up the long mobile staircase to the plane entrance, is very disturbing. I won't be taking British Airways in the future. Many people on these flights were very unhappy.

The food on the flight was of marginal quality. Small bits of chicken, instant mashed potatoes and some carrots. The rolls were very dry, nearly inedible. The seats were quite small and didn’t allow for any shifting of position during the flight. There was limited leg room.0

The seats are so small that you can barely move at all. Don't try to eat with utensils in your seat either - you will elbow your neighbor in the face. Miserably small and I swear they are shrinking every time I fly. Food was meh (per usual), but at least there is free alcohol on an overseas flight. Doesn't make up for sitting in a torture chamber while hurtling through the air with hundreds of fussy people, but it's something. Entertainment options (movies, shows) are okay, nothing special, but at least there are screens, because most of the seats in these large planes do not have adjustable lighting - or air control - that you can get to, it's too high to reach - which makes reading impossible. Zero stars, AA.

Terrible customer service. I booked business class and the counter agent didn’t bother asking me about any choice or preferred seat, basically assigned me that last seat and couldn’t even answer if it was a business class seat. Also iberia lost my suitcase on my flight from JFK to MAD with the layover in BCN. Useless customer service at the counter. Thank goodness I happened to check the baggage claim area of the next flight in…there it was.

Disaster. Downgraded. Zero apology. No effort or coordination between gate and crew. Awful seat blocked by door emergency slide box. Iberia is a mess. App never works. Avoid this airline.

We departed late but made up most of the time in flight. Our ticket was pure economy, so it wasn’t anything fancy; however, I heard that we arrived in Madrid at the exact same time that First Class passengers arrived! Overall, our experience was similar to what we had on other American Airlines transatlantic flights - good value at a reasonable price. We were even able to get our carry-on baggage onto the plane without needing to gate check it.

The crew were friendly and helpful. Iberia lost our luggage on arrival, Friday and we didn't get it until Sunday at 10:00 p.m. local Malaga time. I also paid $382.80 for seat assignments but two out out of the four were not together. Iberia mentioned that it was because the plane was delayed in Madrid before our flight began in LAX. They should compensate us half of my payment.

It was fortunate that the flight arrived in London in accordance with schedule, and the luggage was promptly transferred to the luggage carousel. However, I find it concerning that even minor issues in economy cabins are prevalent within the industry. American Airlines, in particular, appears to have the least legroom and feels more crowded due to the proximity of neighboring passengers. Additionally, the crew’s adherence to protocol is inconsistent. While they may enforce certain rules set by the FAA on a select few individuals, they often overlook numerous violations, such as failing to reset seat recline during landing.

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

Seat pitch is not enough to eat comfortably. When seat in front is reclined, your screen comes closer to your face. Ryanair seats are actually more comfortable.

The leg from Portland to Heathrow was great for a business class ticket. The BA leg from Heathrow to Lisbon was terrible. Basically coach seating with an empty seat between you and next passenger. Absolutely no leg room. Should not have been charged for business class and it was a 3 hour flight.

The flat beds. Other than that, the place was not clean.

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

I have always been pleased with their service. Would not change a thing

Seating and food was the worst we have experienced in 35 years of traveling for both personal and busines .

Economy seats felt more cramped than other flights we have taken.7 hr, painful sitting hours 6 and 7. Web site difficult to deal with. Originally put in for 1 special meal due to type 2. Meal was awful. Tried to change selection to standard for return flight, on app and website, unable to complete that action.

I was sleeping during dinner service, no one bothered to offer meal later, I remained hungry….until I got a morning sandwich!

Need to offer Better food from LAX to London Service from London to Delhi very delayed after take off.

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

Information on your arrival and departure airports