฿11,715 Cheap Flights from Seattle (SEA) to London (LON)

View ฿11,715 flight on Mon, 20 Oct 2025Opens in a new window

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

Prices were available within the past 7 days and start at ฿11,715 for one-way flights and ฿17,845 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Icelandair
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿17,845 Return, found 2 days ago
฿17,845
Return
found 2 days ago
Select Icelandair flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿17,845 found 2 days ago
Icelandair
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿17,900 Return, found 2 days ago
฿17,900
Return
found 2 days ago
Select Icelandair flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿17,900 found 2 days ago
Air Canada
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿23,000 Return, found 2 days ago
฿23,000
Return
found 2 days ago
Select Air Canada flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿23,000 found 2 days ago
United
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿23,585 Return, found 2 days ago
฿23,585
Return
found 2 days ago
Select United flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿23,585 found 2 days ago
United
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿23,610 Return, found 2 days ago
฿23,610
Return
found 2 days ago
Select United flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿23,610 found 2 days ago
United
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿23,765 Return, found 2 days ago
฿23,765
Return
found 2 days ago
Select United flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿23,765 found 2 days ago
United
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿24,195 Return, found 2 days ago
฿24,195
Return
found 2 days ago
Select United flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿24,195 found 2 days ago
Lufthansa
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿24,220 Return, found 2 days ago
฿24,220
Return
found 2 days ago
Select Lufthansa flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿24,220 found 2 days ago
Lufthansa
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿24,245 Return, found 2 days ago
฿24,245
Return
found 2 days ago
Select Lufthansa flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿24,245 found 2 days ago
KLM
Mon, 20 Oct - Tue, 4 Nov
SEA
Seattle
LHR
London
฿24,420 Return, found 2 days ago
฿24,420
Return
found 2 days ago
Select KLM flight, departing Mon, 20 Oct from Seattle to London, returning Tue, 4 Nov, priced at ฿24,420 found 2 days ago

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

October is typically the cheapest month to fly

From ฿15,188 - ฿31,499 per traveller.
Flight from Seattle to London route information
Origin airport
Seattle - Tacoma Intl.
Destination airport
Heathrow
Return price
฿17,845
Distance
7657 km

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 LON-All Airports ticket options cater to your travel preferences, with incredible one-way fares from ฿11,715 and roundtrip prices from ฿17,845. 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 LON-All Airports 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 London (LON-All Airports)?
Round-trip journeys from Seattle - Tacoma Intl. Airport (SEA) to London (LON-All Airports) start from ฿17,845. This is based on fares offered within the last 7 days on Expedia for flights departing within the next year — book now so you don't miss out. 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 London (LON-All Airports)?
Most flights can be cancelled online, but each air carrier has its own terms and conditions. If you do decide to cancel your flight, visit our Customer Service Portal and follow the instructions.
How do I find cheap flights from SEA to London (LON-All Airports) 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 SEA to London (LON-All Airports) flights, you'll see a "no change fees" filter for you to select.
How many hours is the flight from Seattle - Tacoma Intl. Airport (SEA) to London (LON-All Airports)?
Make the 14 hours and 48 minutes between SEA and London (LON-All Airports) as comfortable as you can. Bring the essentials, like a water bottle, toothbrush and toiletries, and simply enjoy the flight!
How far is the flight from SEA to London (LON-All Airports)?
With around 7,700 kilometres separating SEA and London (LON-All Airports), your flight will be a long one. Pack wisely and make your time on board comfortable. Simple things like an eye mask and a good travel pillow can make a massive difference.
Which airlines fly direct from Seattle - Tacoma Intl. Airport (SEA) to London (LON-All Airports)?
You have lots of options when flying from SEA to London (LON-All Airports). Lock in your fare with one of these popular airlines:

  • 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-Tac Airport to London (LON-All Airports) flight tickets cheaper when they're purchased at the last minute?
Booking last minute from SEA to London (LON-All Airports) can be hit-or-miss. It is possible to score a bargain, but you could also miss out entirely! If you'd prefer to play it safe and start planning early on, Expedia compares flight deals up to 12 months in advance. Just remember that not all airlines publish their prices that far in advance. Our suggestion? Check back often as updates are made regularly.

Explore a world of travel with Expedia

London Airports

London

Seattle to Heathrow
฿17,845.00
*Available to Expedia members.