S$400 Cheap Flights from Seattle to London

View S$400 flight on Mon, 17 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 S$400 for one-way flights and S$655 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$655 Return, found 3 days ago
S$655
Return
found 3 days ago
Select Delta flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$655 found 3 days ago
Delta
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$665 Return, found 3 days ago
S$665
Return
found 3 days ago
Select Delta flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$665 found 3 days ago
Air France
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$688 Return, found 3 days ago
S$688
Return
found 3 days ago
Select Air France flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$688 found 3 days ago
Delta
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$690 Return, found 3 days ago
S$690
Return
found 3 days ago
Select Delta flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$690 found 3 days ago
Air France
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$722 Return, found 3 days ago
S$722
Return
found 3 days ago
Select Air France flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$722 found 3 days ago
KLM
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$724 Return, found 3 days ago
S$724
Return
found 3 days ago
Select KLM flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$724 found 3 days ago
United
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$801 Return, found 3 days ago
S$801
Return
found 3 days ago
Select United flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$801 found 3 days ago
Virgin Atlantic
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$810 Return, found 3 days ago
S$810
Return
found 3 days ago
Select Virgin Atlantic flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$810 found 3 days ago
Air Canada
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$828 Return, found 3 days ago
S$828
Return
found 3 days ago
Select Air Canada flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$828 found 3 days ago
Lufthansa
Mon, 17 Nov - Wed, 26 Nov
SEA
Seattle
LHR
London
S$833 Return, found 3 days ago
S$833
Return
found 3 days ago
Select Lufthansa flight, departing Mon, 17 Nov from Seattle to London, returning Wed, 26 Nov, priced at S$833 found 3 days ago

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

October is typically the cheapest month to fly

From S$614 - S$1,200 per traveller.

Graph displaying average flight prices per month

Seattle to London route information
Origin airport
Seattle - Tacoma Intl.
Destination airport
Heathrow
Return price
S$654
Distance
7657 km

Perfect flights from Seattle to London

Your Journey from Seattle to London

Start your unforgettable journey with Expedia. Our broad selection of flights from Seattle to London caters to every travel need. Whether you're yearning for a romantic escape, a solo adventure, or a cultural immersion, we've got you covered.
 

Choosing Your Ideal Flight

With Expedia, you have access to a wide range of airlines, including WestJet, United, Air Canada, Delta, Lufthansa, Virgin Atlantic, British Airways, Air France, KLM. Our selection of flights from Seattle - Tacoma Intl. to LON-All Airports caters to every traveler's requirements, ensuring your journey aligns with your schedule. With options from 20 airlines, you're bound to find the perfect flight.
 

Maximizing Value with Seattle to London Flights

Experience the joy of finding cheap flights from Seattle - Tacoma Intl. to LON-All Airports that fit your budget. Keep an eye out for our special deals and discounts, and check our flexible one-way fares from S$400 and roundtrip prices from S$655*.
 

Pre-Flight Essentials

Ensure a smooth journey from Seattle to London with Expedia. From information about check-in times and in-flight amenities to guidance on baggage policies, we provide all the essentials to prepare you for your flight.
 

Experience the Vibrant London

Picture yourself stepping off the plane in London and immersing yourself in the unique atmosphere of . From local markets to cultural festivals, each city offers its distinct charm. Make the most of your trip by exploring local attractions and indulging in the local cuisine. With Expedia, explore all this and more, tailored to your budget.
 

Added Convenience on Your Seattle to London Flight

Traveling with Expedia is more than just a flight. We offer details about in-flight amenities, baggage policies, and more to ensure a smooth and hassle-free journey. Choose from our variety of airlines and embark on a memorable journey from Seattle to London.
 

Beyond the Flight – Exploring London

With Expedia, your adventure extends beyond the flight. Explore London at your own pace by renting a car or booking a hotel. Discover hidden gems off the beaten path and create unforgettable memories.
 

Book Your Flight from Seattle to London with Confidence

Planning your next great adventure is a breeze with Expedia. Our user-friendly platform, unbeatable prices, and round-the-clock customer support make your travel experience seamless and stress-free. Embark on your journey from Seattle to London with confidence. Book your travel arrangements with Expedia today.
 
*Note: Prices may vary based on availability and are subject to change.

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 S$655. 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
S$654.50
*Available to Expedia members.