SEA - LHR

£268 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 18/7. 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
Travellers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest return fare
£653
Typical prices: £895-£633
Air Canada
Sun 19/7Tue 21/7
SEA - LHR • 2 stops
Cheapest direct flights
£653
Typical prices: £671-£460
Alaska Airlines, British Airways
Sat 26/9Mon 12/10
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 £653 (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 23m
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 27% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 23% price drop
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 Heathrow!
Flight Deals
Booking Insights
Expert advice
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

Sun, 19 Jul - Tue, 21 Jul
Air Canada Logo
05:45 - 16:25
SEA
-
LHR
26h 40m
2 stops
Air Canada Logo
10:15 - 22:42
LHR
-
SEA
20h 27m
2 stops
£653Air Canada
Sun, 19 Jul - Tue, 4 Aug
Icelandair Logo
15:40 - 11:55
SEA
-
LHR
12h 15m
1 stop
Icelandair Logo
21:25 - 11:45
LHR
-
SEA
22h 20m
1 stop
£654Icelandair
Thu, 3 Sep - Sat, 19 Sep
Scandinavian Airlines Logo
09:10 - 16:00
SEA
-
LHR
22h 50m
2 stops
Scandinavian Airlines Logo
06:40 - 13:45
LHR
-
SEA
15h 05m
1 stop
£654Scandinavian Airlines
Sun, 2 Aug - Tue, 8 Sep
Scandinavian Airlines Logo
15:55 - 16:00
SEA
-
LHR
16h 05m
1 stop
Scandinavian Airlines Logo
07:05 - 13:45
LHR
-
SEA
14h 40m
2 stops
£655Scandinavian Airlines
Sun, 2 Aug - Tue, 8 Sep
Scandinavian Airlines Logo
15:55 - 16:25
SEA
-
LHR
16h 30m
2 stops
Scandinavian Airlines Logo
07:05 - 13:45
LHR
-
SEA
14h 40m
2 stops
£656Scandinavian Airlines
Mon, 31 Aug - Mon, 14 Sep
Multiple Airlines Logo
23:25 - 20:20
SEA
-
LHR
12h 55m
1 stop
Multiple Airlines Logo
17:00 - 18:55
LHR
-
SEA
9h 55mdirect
£657Multiple Airlines
Sun, 25 Oct - Thu, 12 Nov
Lufthansa Logo
10:10 - 11:50
SEA
-
LHR
18h 40m
1 stop
Lufthansa Logo
11:10 - 22:29
LHR
-
SEA
19h 19m
2 stops
£657Lufthansa
Wed, 16 Sep - Fri, 25 Sep
British Airways Logo
13:30 - 06:45
SEA
-
LHR
9h 15mdirect
British Airways Logo
09:50 - 11:35
LHR
-
SEA
9h 45mdirect
£658British Airways
Thu, 3 Sep - Sat, 19 Sep
Scandinavian Airlines Logo
09:10 - 16:00
SEA
-
LHR
22h 50m
2 stops
Scandinavian Airlines Logo
06:40 - 13:45
LHR
-
SEA
15h 05m
2 stops
£659Scandinavian Airlines
Fri, 18 Sep - Sat, 3 Oct
Multiple Airlines Logo
15:40 - 11:55
SEA
-
LHR
12h 15m
1 stop
Multiple Airlines Logo
17:00 - 18:55
LHR
-
SEA
9h 55mdirect
£660Multiple 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 July.

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, Thursday is the cheapest day to fly on average and Monday 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 £481 (return) on average. On the other hand, the most expensive months are June and December, where the average cost of round-trip tickets is £903 and £765 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 £694 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 27% 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 seasonJanuary
Cheapest flight£268
Best time to beat the crowds (23% less expensive on average)
Most popular time to fly and prices are also 15% 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 3 days, the lowest price for a flight from Seattle to London Heathrow Airport was £268 for a one-way ticket and £653 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: KLM, Air France, Delta, Virgin Atlantic, Scandinavian Airlines, American Airlines, and Air Europa.

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

    The Airbus A330-900neo 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 £587 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 £522 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 £466 or less one-way and £736 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 689 reviews
6.9Food
7.5Entertainment
7.3Comfort
7.7Boarding
8.1Crew
Airline reviews

Seating and zone. The minor I went with didn’t even seat close to me

4.0 OkayAnonymous, Mar 2026
BOS - LIS
Read more Virgin Atlantic reviews

Seating and zone. The minor I went with didn’t even seat close to me

My seat 3G did not go down fully and the buttons were not working properly

Food has been disappointing in both legs of flight to india

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

Boarding process was chaotic. Confusion over Boarding gates: gate 55 or gate 56 ???. Unnecessary standing in long lines to board. Better to call out Boarding groups one at a time and everyone else to sit. Airline only has 2 Boarding groups 1-3 and 4-9. That causes over crowding and chaos

Lady next to me was coughing profusely the entire flight, other lady moved seats because of it, 8 hours of that during an overnight flight is a bit much.

3.5 hr delay leaving Pittsburgh, notifications for which were incomplete and untimely. Connecting flight was automatically switched to one requiring more than a 30 hour layover! After waiting in a long queue, customer service reduced layover to 11 hours and also set up an earlier standby. The standby had empty seats, but the gate agent couldn't change our tickets! On top of all that my luggage was lost and has yet to even be located, much less returned 5 (FIVE!) days later. Too bad there's no rating below poor.

Canceled flight late London to Florence. Help at airport very poor. Treated poorly. Had to sleep in the airport. Lost bags- still do not have them. Horrible. I should be reimbursed!

The seats are extra cramped if you are taller than 5’8! Spring for the extra legroom seats for sure if you have a long flight!

Very disappointed with British Airways. It has been over 24 hours and I still have not received my checked baggage or any proper update. Customer support has been unresponsive, making the situation even more frustrating. Poor baggage handling and lack of communication seriously impacted my travel experience.

Flight was good but temp in the cabin was cold.

I like American Airlines and their safety record. They provide quality service and a feel safe enough to prefer American Airlines over other carriers even if I have to pay a little more.

Cancelled flight and re booked seats were a downgrade. British Airways said the upgrade was t available but when I checked it was but then they wouldn’t make it right

Boarding was orderly, pilot and flight attendants were nice, entertainment options were good, and low sodium meals were quite tasty.

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

Information on your arrival and departure airports