€254 Cheap Flights Seattle to London (SEA-LON)

View €254 flight on Sun, 23 Nov 2025Opens in a new window

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

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Cheap flights from Seattle to London (SEA-LON)

Prices were available within the past 7 days and start at €254 for one-way flights and €410 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Aer Lingus
Tue, 9 Sep - Tue, 16 Sep
SEA
Seattle
LHR
London
€410 Return, found 4 days ago
€410
Return
found 4 days ago
Select Aer Lingus flight, departing Tue, 9 Sep from Seattle to London, returning Tue, 16 Sep, priced at €410 found 4 days ago
Virgin Atlantic
Sun, 24 Aug - Tue, 9 Sep
SEA
Seattle
LHR
London
€434 Return, found 2 days ago
€434
Return
found 2 days ago
Select Virgin Atlantic flight, departing Sun, 24 Aug from Seattle to London, returning Tue, 9 Sep, priced at €434 found 2 days ago
Iberia
Sun, 24 Aug - Tue, 9 Sep
SEA
Seattle
LHR
London
€440 Return, found 2 days ago
€440
Return
found 2 days ago
Select Iberia flight, departing Sun, 24 Aug from Seattle to London, returning Tue, 9 Sep, priced at €440 found 2 days ago
American Airlines
Sun, 17 Aug - Tue, 2 Sep
SEA
Seattle
LHR
London
€440 Return, found 2 days ago
€440
Return
found 2 days ago
Select American Airlines flight, departing Sun, 17 Aug from Seattle to London, returning Tue, 2 Sep, priced at €440 found 2 days ago
Icelandair
Mon, 6 Oct - Sat, 11 Oct
SEA
Seattle
LGW
London
€441 Return, found 4 days ago
€441
Return
found 4 days ago
Select Icelandair flight, departing Mon, 6 Oct from Seattle to London, returning Sat, 11 Oct, priced at €441 found 4 days ago
Delta
Sun, 10 Aug - Tue, 26 Aug
SEA
Seattle
LHR
London
€442 Return, found 1 hour ago
€442
Return
found 1 hour ago
Select Delta flight, departing Sun, 10 Aug from Seattle to London, returning Tue, 26 Aug, priced at €442 found 1 hour ago
Air France
Sun, 24 Aug - Tue, 9 Sep
SEA
Seattle
LHR
London
€478 Return, found 2 days ago
€478
Return
found 2 days ago
Select Air France flight, departing Sun, 24 Aug from Seattle to London, returning Tue, 9 Sep, priced at €478 found 2 days ago
KLM
Mon, 4 Aug - Tue, 19 Aug
SEA
Seattle
LHR
London
€484 Return, found 1 day ago
€484
Return
found 1 day ago
Select KLM flight, departing Mon, 4 Aug from Seattle to London, returning Tue, 19 Aug, priced at €484 found 1 day ago
British Airways
Sun, 24 Aug - Tue, 9 Sep
SEA
Seattle
LHR
London
€501 Return, found 2 days ago
€501
Return
found 2 days ago
Select British Airways flight, departing Sun, 24 Aug from Seattle to London, returning Tue, 9 Sep, priced at €501 found 2 days ago
United
Tue, 9 Sep - Tue, 16 Sep
SEA
Seattle
LHR
London
€532 Return, found 4 days ago
€532
Return
found 4 days ago
Select United flight, departing Tue, 9 Sep from Seattle to London, returning Tue, 16 Sep, priced at €532 found 4 days ago

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

October is typically the cheapest month to fly

From €415 - €804 per traveller.

Graph displaying average flight prices per month

Seattle to London route information
Origin airport
Seattle - Tacoma Intl.
Destination airport
Heathrow
Return price
€410
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 €254 and roundtrip prices from €410. 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 €410. 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.

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