$187 Cheap Flights from Seattle (SEA) to London (LHR)

View $187 flight on Sun, Oct 5, 2025Opens in a new window

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

Cheap Flights from Seattle to London (SEA-LHR)

Prices were available within the past 7 days and start at $187 for one-way flights and $403 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Icelandair
Fri, Nov 7 - Sat, Nov 15
SEA
Seattle
LHR
London
$403 Roundtrip, found 1 day ago
$403
Roundtrip
found 1 day ago
Select Icelandair flight, departing Fri, Nov 7 from Seattle to London, returning Sat, Nov 15, priced at $403 found 1 day ago
Delta
Sun, Aug 24 - Mon, Sep 1
SEA
Seattle
LHR
London
$418 Roundtrip, found 13 hours ago
$418
Roundtrip
found 13 hours ago
Select Delta flight, departing Sun, Aug 24 from Seattle to London, returning Mon, Sep 1, priced at $418 found 13 hours ago
Virgin Atlantic
Sun, Aug 17 - Wed, Aug 27
SEA
Seattle
LHR
London
$425 Roundtrip, found 16 hours ago
$425
Roundtrip
found 16 hours ago
Select Virgin Atlantic flight, departing Sun, Aug 17 from Seattle to London, returning Wed, Aug 27, priced at $425 found 16 hours ago
American Airlines
Sun, Aug 17 - Wed, Aug 27
SEA
Seattle
LHR
London
$430 Roundtrip, found 16 hours ago
$430
Roundtrip
found 16 hours ago
Select American Airlines flight, departing Sun, Aug 17 from Seattle to London, returning Wed, Aug 27, priced at $430 found 16 hours ago
Air Canada
Sun, Aug 17 - Wed, Aug 27
SEA
Seattle
LHR
London
$432 Roundtrip, found 16 hours ago
$432
Roundtrip
found 16 hours ago
Select Air Canada flight, departing Sun, Aug 17 from Seattle to London, returning Wed, Aug 27, priced at $432 found 16 hours ago
Iberia
Sun, Aug 17 - Thu, Aug 28
SEA
Seattle
LHR
London
$441 Roundtrip, found 2 days ago
$441
Roundtrip
found 2 days ago
Select Iberia flight, departing Sun, Aug 17 from Seattle to London, returning Thu, Aug 28, priced at $441 found 2 days ago
Air France
Sun, Aug 17 - Wed, Aug 27
SEA
Seattle
LHR
London
$469 Roundtrip, found 16 hours ago
$469
Roundtrip
found 16 hours ago
Select Air France flight, departing Sun, Aug 17 from Seattle to London, returning Wed, Aug 27, priced at $469 found 16 hours ago
KLM
Sun, Aug 24 - Mon, Sep 1
SEA
Seattle
LHR
London
$470 Roundtrip, found 13 hours ago
$470
Roundtrip
found 13 hours ago
Select KLM flight, departing Sun, Aug 24 from Seattle to London, returning Mon, Sep 1, priced at $470 found 13 hours ago
United
Sun, Aug 17 - Wed, Aug 27
SEA
Seattle
LHR
London
$476 Roundtrip, found 16 hours ago
$476
Roundtrip
found 16 hours ago
Select United flight, departing Sun, Aug 17 from Seattle to London, returning Wed, Aug 27, priced at $476 found 16 hours ago
Lufthansa
Tue, Nov 4 - Fri, Nov 14
SEA
Seattle
LHR
London
$533 Roundtrip, found 3 hours ago
$533
Roundtrip
found 3 hours ago
Select Lufthansa flight, departing Tue, Nov 4 from Seattle to London, returning Fri, Nov 14, priced at $533 found 3 hours ago

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

February is typically the cheapest month to fly

From $507 - $886 per traveler.

Graph displaying average flight prices per month

Alternative airports near London

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Gatwick LGW. Average driving time to city center is 52 minutes. Flights from $1,056
LGW
Gatwick
Average driving time to city center52 min
Flights from $1,056
Select flight to London City LCY. Closest option available. Average driving time to city center is 21 minutes. Flights from $719
LCY
London City
Closest
Average driving time to city center21 min
Flights from $719
Flights from Seattle (SEA) to London (LHR)
Origin airport
Seattle - Tacoma Intl.
Destination airport
Heathrow
Airlines serving
Aer Lingus, Air Canada, Air France, Alaska Airlines, American Airlines, Austrian Airlines, British Airways, Brussels Airlines, Delta, Finnair, Iberia, Icelandair, JetBlue Airways, KLM, Lufthansa, Scandinavian Airlines, Turkish Airlines, United, Virgin Atlantic, WestJet
Roundtrip price
$402
Distance
4786 mi
Average flight time
17 hours 33 mins

Seattle to London Flights

The cheapest times to fly from Seattle to London

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Seattle to London are during the month of November. You can find some of the cheapest flights from Seattle to London with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Seattle to London

Sunday is one of the best days to book for cheap flights from Seattle to London: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Seattle to London

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Seattle to London in 2025. You can also book with separate airlines for your outbound and return journeys, from $187 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Seattle to London flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Seattle to London airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR) cost?
You can find cheap return fares from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR) starting from $505. Book your seat and start your adventure. This information is based on the cheapest price found on Expedia for this return journey departing within the next three months. This airfare is for a Virgin Atlantic flight leaving SEA on July 23 2025 and touching down at LHR. The price was last updated on June 29 2025 and has not changed since.
What is the cheapest month to fly from SEA to LHR?
The cheapest flights from SEA to LHR are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
Which airlines fly direct from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR)?
Fly straight to Heathrow Airport (LHR). 3 carriers operate direct flights from Seattle - Tacoma Intl. Airport (SEA), including:

  • British Airways
  • Virgin Atlantic
  • Delta Air Lines

What is the cheapest airline that flies from SEA to LHR?
With tickets starting at $414 for a one-way journey from SEA to LHR, British Airways is currently the cheapest carrier for this route. This fare is based on the lowest price found on Expedia departing within the next three months. The flight takes off from SEA on September 23 2025. Prices were last updated on June 29 2025 and have not changed since.
How many flights per day from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR)?
When taking off from Seattle - Tacoma Intl. Airport (SEA), you'll have your pick from an average of 2 daily nonstop flights to Heathrow Airport (LHR).
What are the most popular departure times for flights from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR)?
More people fly between SEA and LHR at 5 PM than at any other point in the day. Looking for a quieter experience? Consider flying outside peak hours and you're likely to save on your fare as well.
What day of the week has the most flights from SEA to LHR?
If you travel on a Friday, you'll get the greatest range of options for flights from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR).
What is the earliest flight from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR)?
The first flight of the day departing from Seattle - Tacoma Intl. Airport (SEA) is at around 1:35PM UTC-8. Catch this flight and you'll land at Heathrow Airport (LHR) at approximately 7:00AM UTC+0. The entire trip takes 9h 25m.
How long does it take to fly from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR)?
Flights from SEA to LHR have an average travel time of 9 hours and 25 minutes. The distance between the two airports is 4,800 mi.
What airline has the least delays from SEA to LHR?
With 80% of flights generally landing on schedule, American Airlines has the best on-time performance for nonstop flights from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR). To keep track of your flight status and get notified if anything changes, head to the Expedia App.
What is the best time to fly from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR)?
To land at Heathrow Airport (LHR) without delays, book a flight that takes off from Seattle - Tacoma Intl. Airport (SEA) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this time.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for London from Seattle - Tacoma Intl. Airport (SEA)?
If you're taking a direct flight from Seattle - Tacoma Intl. Airport (SEA) to London, Heathrow Airport (LHR) is the only airport you can land at.
Is it cheaper to buy a plane ticket from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR) last-minute?
Booking your ticket from SEA to LHR right before your journey is typically more expensive. But if there's some wiggle room with your departure times and dates, you could land a cheap last-minute fare.
Is it cheaper to book a SEA to LHR flight and hotel package?
Booking a SEA to LHR flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your trip all in one place. Select from our extensive range of accommodations and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport (LHR)?
In most cases, you can cancel or reschedule your SEA to LHR flight. However, additional fees may apply, especially if your booking was made over 24 hours ago. Check your itinerary for the airline's fees and guidelines on flight changes, or if you'd like further information, head to our Customer Service portal.

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*Available to One Key members.