฿8,475 Cheap Flights from Seattle (SEA) to London (LHR)

View ฿8,475 flight on Sun, 1 Feb 2026Opens in a new window

Popular airlines from Seattle-Tacoma International Airport (SEA) to Heathrow Airport (LHR)

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Cheap Flights from Seattle (SEA) to London (LHR)

Prices were available within the past 7 days and start at ฿8,475 for one-way flights and ฿17,085 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Icelandair
Wed, 19 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
฿17,085 Return, found 2 days ago
฿17,085
Return
found 2 days ago
Select Icelandair flight, departing Wed, 19 Nov from Seattle to London, returning Wed, 26 Nov, priced at ฿17,085 found 2 days ago
Icelandair
Sat, 21 Mar - Sun, 29 Mar
SEA
Seattle
LHR
London
฿17,905 Return, found 3 days ago
฿17,905
Return
found 3 days ago
Select Icelandair flight, departing Sat, 21 Mar from Seattle to London, returning Sun, 29 Mar, priced at ฿17,905 found 3 days ago
United
Wed, 19 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
฿19,820 Return, found 2 days ago
฿19,820
Return
found 2 days ago
Select United flight, departing Wed, 19 Nov from Seattle to London, returning Wed, 26 Nov, priced at ฿19,820 found 2 days ago
Delta
Wed, 19 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
฿19,930 Return, found 2 days ago
฿19,930
Return
found 2 days ago
Select Delta flight, departing Wed, 19 Nov from Seattle to London, returning Wed, 26 Nov, priced at ฿19,930 found 2 days ago
Air Canada
Wed, 19 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
฿20,035 Return, found 2 days ago
฿20,035
Return
found 2 days ago
Select Air Canada flight, departing Wed, 19 Nov from Seattle to London, returning Wed, 26 Nov, priced at ฿20,035 found 2 days ago
Delta
Wed, 19 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
฿20,190 Return, found 2 days ago
฿20,190
Return
found 2 days ago
Select Delta flight, departing Wed, 19 Nov from Seattle to London, returning Wed, 26 Nov, priced at ฿20,190 found 2 days ago
Delta
Wed, 19 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
฿20,350 Return, found 2 days ago
฿20,350
Return
found 2 days ago
Select Delta flight, departing Wed, 19 Nov from Seattle to London, returning Wed, 26 Nov, priced at ฿20,350 found 2 days ago
Lufthansa
Wed, 19 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
฿20,445 Return, found 2 days ago
฿20,445
Return
found 2 days ago
Select Lufthansa flight, departing Wed, 19 Nov from Seattle to London, returning Wed, 26 Nov, priced at ฿20,445 found 2 days ago
Lufthansa
Wed, 19 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
฿20,690 Return, found 2 days ago
฿20,690
Return
found 2 days ago
Select Lufthansa flight, departing Wed, 19 Nov from Seattle to London, returning Wed, 26 Nov, priced at ฿20,690 found 2 days ago
Air Canada
Wed, 19 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
฿20,825 Return, found 2 days ago
฿20,825
Return
found 2 days ago
Select Air Canada flight, departing Wed, 19 Nov from Seattle to London, returning Wed, 26 Nov, priced at ฿20,825 found 2 days ago

Find the cheapest month to fly from Seattle (SEA) to London (LHR)

October is typically the cheapest month to fly

From ฿15,523 - ฿33,575 per traveller.
Flight from Seattle to London route information
Origin airport
Seattle - Tacoma Intl.
Destination airport
Heathrow
Return price
฿17,085
Distance
7657 km
Average flight time
16 hours 38 mins

Perfect flights from Seattle to London

Embark on an unforgettable journey without breaking the bank with Expedia's incredible deals on cheap flights from Seattle to London. Whether you're aching for a romantic escape with your partner, craving an adventurous solo expedition, or yearning to immerse yourself in the local history and culture, we've got you covered.
 
Picture yourself strolling through the streets of , surrounded by breathtaking architecture and absorbing the vibrant atmosphere of this captivating city. Indulge in the mouth-watering local specialties, from tantalizing street food to exquisite fine dining. With Expedia, you can experience all of this and more, without sacrificing your budget.
 
Our flexible Seattle - Tacoma Intl. to Heathrow ticket options cater to your travel preferences, with incredible one-way fares from ฿8,475 and roundtrip prices from ฿17,085. Whether you're planning a short city break or a longer adventure, our dynamic pricing ensures that you find the best deals for your journey.
 
But the magic doesn't stop there. Expedia offers a range of partner services to enhance your trip. Rent a car at Heathrow and explore and its surrounding areas at your own pace. Discover hidden gems off the beaten path, and create unforgettable memories. We also provide a handpicked selection of accommodations, from charming bed and breakfasts to luxury hotels, ensuring that you have a comfortable and memorable stay.
 
Planning your next great adventure is a breeze with Expedia. Our user-friendly platform, unbeatable prices, and round-the-clock customer support are designed to make your travel experience seamless and stress-free. So, why wait? Book your to travel arrangements today and embark on the journey of a lifetime in London.

Frequently asked questions

How much is a flight from Sea-Tac Airport to Heathrow Airport (LHR)?
If you're travelling between SEA and London Heathrow, round-trip journeys start from ฿17,085. This price is based on fares listed within the last 7 days on Expedia for flights departing within the next year, so don't delay. Book today and save yourself money and time. Prices and availability are subject to change. Additional terms apply.
Do I need to pay a cancellation fee if I cancel my flight from SEA to Heathrow Airport?
The majority of flights can be cancelled online, but whether you are charged a fee all comes down to your airline. If you do need to cancel your trip, follow the instructions in the Customer Service Portal.
How do I find cheap flights from Seattle - Tacoma Intl. Airport (SEA) to LHR that have flexible change policies?
Many airlines offer the option to reschedule your flight without a change fee. All you pay is the difference between the original flight and the new flight. When you're searching for Seattle - Tacoma Intl. Airport (SEA) to London Heathrow flights, you'll see a "no change fees" filter for you to select.
How far is the flight from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport?
With a flight distance of 7,700 kilometres between Sea-Tac Airport and Heathrow Airport (LHR), this is a long trip. Be sure to drink plenty of water and go for a short walk down the aisle every now and then.
Which airlines fly direct from SEA to Heathrow Airport (LHR)?
It's easy to fly directly from Sea-Tac Airport to Heathrow Airport. Below are the most sought-after carriers that offer nonstop services on this route:

  • Virgin Atlantic - (VS) with 30 monthly flights
  • American Airlines - (AA) with 30 monthly flights
  • British Airways - (BA) with 30 monthly flights
  • Delta Air Lines - (DL) with 17 monthly flights

Are SEA to LHR flight tickets cheaper when they're purchased at the last minute?
Flight prices are constantly going up and down, so there are no guarantees. While last-minute deals between Seattle - Tacoma Intl. Airport (SEA) and Heathrow Airport are of course possible, it's also a good idea to keep track of prices well before you fly. In fact, some airlines announce their prices up to a year prior to the departure date. Expedia is constantly updating the best bargains around, so keep checking back and be ready to lock in your seat when the price dips.

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