$539 Cheap Flights from London (LHR) to Seattle (SEA)

View $539 flight on Mon, May 4, 2026Opens in a new window

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

  • Plan, book, fly with confidence

  • trending down icon

    Be in the know

    Get alerts if flight prices drop or rise*
  • bex rewards loyalty icon

    Book smarter

    Save up to 30% on select hotels after you book a flight*
  • one key icon

    Earn twice

    Earn your airline miles on top of our OneKeyCash
    Learn about One Key

Cheap Flights from London to Seattle (LHR-SEA)

Prices were available within the past 7 days and start at $539 for one-way flights and $578 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Icelandair
Thu, Oct 2 - Wed, Oct 8
LHR
London
SEA
Seattle
$578 Roundtrip, found 21 hours ago
$578
Roundtrip
found 21 hours ago
Select Icelandair flight, departing Thu, Oct 2 from London to Seattle, returning Wed, Oct 8, priced at $578 found 21 hours ago
Scandinavian Airlines
Sat, Sep 6 - Sun, Oct 5
LHR
London
SEA
Seattle
$605 Roundtrip, found 4 days ago
$605
Roundtrip
found 4 days ago
Select Scandinavian Airlines flight, departing Sat, Sep 6 from London to Seattle, returning Sun, Oct 5, priced at $605 found 4 days ago
Swiss International Air Lines
Sat, Sep 6 - Mon, Sep 15
LHR
London
SEA
Seattle
$651 Roundtrip, found 2 days ago
$651
Roundtrip
found 2 days ago
Select Swiss International Air Lines flight, departing Sat, Sep 6 from London to Seattle, returning Mon, Sep 15, priced at $651 found 2 days ago
United
Fri, Aug 29 - Sun, Sep 14
LHR
London
SEA
Seattle
$658 Roundtrip, found 16 hours ago
$658
Roundtrip
found 16 hours ago
Select United flight, departing Fri, Aug 29 from London to Seattle, returning Sun, Sep 14, priced at $658 found 16 hours ago
Air Canada
Mon, Oct 6 - Mon, Oct 13
LHR
London
SEA
Seattle
$662 Roundtrip, found 1 hour ago
$662
Roundtrip
found 1 hour ago
Select Air Canada flight, departing Mon, Oct 6 from London to Seattle, returning Mon, Oct 13, priced at $662 found 1 hour ago
American Airlines
Mon, Aug 18 - Tue, Sep 30
LHR
London
SEA
Seattle
$673 Roundtrip, found 2 days ago
$673
Roundtrip
found 2 days ago
Select American Airlines flight, departing Mon, Aug 18 from London to Seattle, returning Tue, Sep 30, priced at $673 found 2 days ago
Brussels Airlines
Fri, Oct 3 - Tue, Oct 14
LHR
London
SEA
Seattle
$677 Roundtrip, found 9 hours ago
$677
Roundtrip
found 9 hours ago
Select Brussels Airlines flight, departing Fri, Oct 3 from London to Seattle, returning Tue, Oct 14, priced at $677 found 9 hours ago
Austrian Airlines
Wed, Sep 10 - Thu, Sep 18
LHR
London
SEA
Seattle
$677 Roundtrip, just found
$677
Roundtrip
just found
Select Austrian Airlines flight, departing Wed, Sep 10 from London to Seattle, returning Thu, Sep 18, priced at $677 just found
British Airways
Tue, Sep 23 - Thu, Nov 6
LHR
London
SEA
Seattle
$678 Roundtrip, found 2 hours ago
$678
Roundtrip
found 2 hours ago
Select British Airways flight, departing Tue, Sep 23 from London to Seattle, returning Thu, Nov 6, priced at $678 found 2 hours ago
Aer Lingus
Wed, Sep 10 - Thu, Sep 18
LHR
London
SEA
Seattle
$678 Roundtrip, just found
$678
Roundtrip
just found
Select Aer Lingus flight, departing Wed, Sep 10 from London to Seattle, returning Thu, Sep 18, priced at $678 just found

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

February is typically the cheapest month to fly

From $486 - $967 per traveler.

Graph displaying average flight prices per month

Alternative airports near Seattle

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

Select flight to Seattle - Tacoma Intl. SEA. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $590
SEA
Seattle - Tacoma Intl.
Cheapest
Average driving time to city center20 min
Flights from $590
0
Flights from London (LHR) to Seattle (SEA)
Origin airport
Heathrow
Destination airport
Seattle - Tacoma Intl.
Airlines serving
Aer Lingus, Air Canada, Air France, American Airlines, Austrian Airlines, British Airways, Brussels Airlines, Delta, Finnair, Iberia, Icelandair, JetBlue Airways, KLM, Lufthansa, Scandinavian Airlines, Swiss International Air Lines, Turkish Airlines, United, Virgin Atlantic, WestJet
Roundtrip price
$577
Distance
4786 mi

London to Seattle Flights

The cheapest times to fly from London to Seattle

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 London to Seattle are during the month of October. You can find some of the cheapest flights from London to Seattle with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from London to Seattle

Sunday is one of the best days to book for cheap flights from London to Seattle: 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 London to Seattle

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 London to Seattle in 2025. You can also book with separate airlines for your outbound and return journeys, from $539 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 London to Seattle 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 London to Seattle 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 Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA) cost?
You'll find cheap return tickets from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA) starting at $665. Book a seat and get ready to go. 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 British Airways flight leaving LHR on August 18 2025 and touching down at SEA. The price was last updated on July 23 2025 and has not changed since.
What is the cheapest month to fly from LHR to SEA?
The cheapest flights from LHR to SEA 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 Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA)?
Take your pick of 3 carriers that fly directly from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA). These include:

  • British Airways
  • Virgin Atlantic
  • Delta Air Lines

What is the cheapest airline that flies from LHR to SEA?
With fares starting at $1624 for a one-way flight from LHR to SEA, Delta is currently the cheapest carrier operating this route. This fare is based on the lowest price found on Expedia departing within the next three months. The flight takes off from LHR on October 6 2025. Prices were last updated on July 23 2025 and have not changed since.
How many flights per day from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA)?
With an average of 2 direct flights that operate from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA) each day, you'll be jetting off in no time.
What are the most popular departure times for flights from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA)?
More people fly between LHR and SEA at 3 PM than at any other time. Looking for a quieter experience? Pick a flight outside the busiest times and it's possible you'll save on your fare as well.
What day of the week has the most flights from LHR to SEA?
Sunday offers the most flights from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA). Consider taking off on this day and you'll have a greater chance of finding a departure that fits your schedule.
What is the earliest flight from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA)?
The first flight of the day out of Heathrow Airport (LHR) is at around 9:25AM UTC+0. Catch this flight and you'll touch down at Seattle - Tacoma Intl. Airport (SEA) at approximately 11:20AM UTC-8. The total travel time is 9h 55m.
How long does it take to fly from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA)?
Flights from LHR to SEA have an average travel time of 9 hours and 57 minutes. The total distance between the two airports is 4,800 mi.
What airline has the least delays from LHR to SEA?
KLM has the strongest track record for on-time direct flights from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA), with an on-time score of 81%. Use the Expedia App to see your journey status before you leave and receive notifications about any trip changes.
What is the best time to fly from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA)?
To avoid possible delays on the Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA) route, aim to travel before 3 PM. Later departures are 22% more likely to be canceled.**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 Seattle from Heathrow Airport (LHR)?
Check out your flight options from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA). This is the only Seattle airport you can arrive at if you're taking a direct flight.
Is it cheaper to buy a plane ticket from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA) last-minute?
Last-minute fares from LHR to SEA are typically more expensive. To lock in the best prices, start looking for flights ahead of time. That being said, if you can play around with your travel dates, you may find a cheap fare right before your journey.
Is it cheaper to book a LHR to SEA flight and hotel package?
You can save money by booking a LHR to SEA flight and hotel package compared to booking separately. In fact, you could save hundreds of dollars by bundling with Expedia. And it's simple to manage everything in one place. After choosing your preferred flights and accommodations, consider other add-ons like car rentals, activities and tours.
Can I cancel or change the date of my flight from Heathrow Airport (LHR) to Seattle - Tacoma Intl. Airport (SEA)?
If you booked your LHR to SEA flight in the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the ticket type you purchased, additional charges may apply for changes after that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal for more details.

Explore a world of travel with Expedia

*Available to One Key members.