₩428,300 Cheap Flights from Seattle (SEA) to London (LHR)

View ₩428,300 flight on Tue, Oct 7, 2025Opens in a new window

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

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Cheap Flights from Seattle to London (SEA-LHR)

Prices were available within the past 7 days and start at ₩428,300 for one-way flights and ₩744,200 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Icelandair
Mon, Sep 1 - Fri, Sep 5
SEA
Seattle
LHR
London
₩744,200 Roundtrip, found 1 day ago
₩744,200
Roundtrip
found 1 day ago
Select Icelandair flight, departing Mon, Sep 1 from Seattle to London, returning Fri, Sep 5, priced at ₩744,200 found 1 day ago
Icelandair
Wed, Sep 3 - Wed, Sep 10
SEA
Seattle
LHR
London
₩746,500 Roundtrip, found 1 day ago
₩746,500
Roundtrip
found 1 day ago
Select Icelandair flight, departing Wed, Sep 3 from Seattle to London, returning Wed, Sep 10, priced at ₩746,500 found 1 day ago
United
Thu, Sep 11 - Wed, Sep 17
SEA
Seattle
LHR
London
₩766,800 Roundtrip, found 5 days ago
₩766,800
Roundtrip
found 5 days ago
Select United flight, departing Thu, Sep 11 from Seattle to London, returning Wed, Sep 17, priced at ₩766,800 found 5 days ago
United
Thu, Sep 11 - Wed, Sep 17
SEA
Seattle
LHR
London
₩776,000 Roundtrip, found 5 days ago
₩776,000
Roundtrip
found 5 days ago
Select United flight, departing Thu, Sep 11 from Seattle to London, returning Wed, Sep 17, priced at ₩776,000 found 5 days ago
Virgin Atlantic
Sun, Sep 14 - Sun, Sep 21
SEA
Seattle
LHR
London
₩785,800 Roundtrip, found 5 days ago
₩785,800
Roundtrip
found 5 days ago
Select Virgin Atlantic flight, departing Sun, Sep 14 from Seattle to London, returning Sun, Sep 21, priced at ₩785,800 found 5 days ago
Air Canada
Sun, Sep 14 - Sun, Sep 21
SEA
Seattle
LHR
London
₩786,000 Roundtrip, found 5 days ago
₩786,000
Roundtrip
found 5 days ago
Select Air Canada flight, departing Sun, Sep 14 from Seattle to London, returning Sun, Sep 21, priced at ₩786,000 found 5 days ago
United
Thu, Sep 11 - Wed, Sep 17
SEA
Seattle
LHR
London
₩787,300 Roundtrip, found 5 days ago
₩787,300
Roundtrip
found 5 days ago
Select United flight, departing Thu, Sep 11 from Seattle to London, returning Wed, Sep 17, priced at ₩787,300 found 5 days ago
Delta
Sun, Sep 14 - Sun, Sep 21
SEA
Seattle
LHR
London
₩793,600 Roundtrip, found 5 days ago
₩793,600
Roundtrip
found 5 days ago
Select Delta flight, departing Sun, Sep 14 from Seattle to London, returning Sun, Sep 21, priced at ₩793,600 found 5 days ago
United
Sun, Sep 14 - Sun, Sep 21
SEA
Seattle
LHR
London
₩793,800 Roundtrip, found 5 days ago
₩793,800
Roundtrip
found 5 days ago
Select United flight, departing Sun, Sep 14 from Seattle to London, returning Sun, Sep 21, priced at ₩793,800 found 5 days ago
Lufthansa
Sun, Sep 14 - Sun, Sep 21
SEA
Seattle
LHR
London
₩854,900 Roundtrip, found 5 days ago
₩854,900
Roundtrip
found 5 days ago
Select Lufthansa flight, departing Sun, Sep 14 from Seattle to London, returning Sun, Sep 21, priced at ₩854,900 found 5 days ago

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

October is typically the cheapest month to fly

From ₩660,966 - ₩1,110,987 per traveler.

Graph displaying average flight prices per month

Flights from Seattle (SEA) to London (LHR)
Origin airport
Seattle - Tacoma Intl.
Destination airport
Heathrow
Airlines serving
Aer Lingus, Air Canada, Air France, American Airlines, Austrian Airlines, British Airways, Delta, Finnair, Iberia, Icelandair, KLM, Lufthansa, Turkish Airlines, United, WestJet
Roundtrip price
₩744,200
Distance
7657 km
Average flight time
17 hours 33 mins

Seattle to London Flights

Sometimes you just need to get out of town or maybe you’re looking for a change of scenery. Regardless of the reason, a flight from Seattle to London will do just the trick! Go on, plan to see all the famous landmarks and eat your weight in the local cuisine. Your trip is beckoning, so answer the call by packing your suitcase and filling your travel itinerary with exploring London.

Whether you’re flying for business or jet-setting on your personal time, you’ve come to the right place. Here at Expedia.com, we’ll pair you up with SEA to LHR flights that won’t make your bank account wince. Ready to temporarily leave behind Seattle for new horizons? Browse through our cheap airfare, and filter by flight times and dates until you find just what you had in mind. From flights without layovers to ones that arrive early in the morning, you’ll come across plane tickets that suit your travel preferences. You can even bundle your flight to LHR with hotels and car rentals to score even bigger savings.

All set to hit the clouds? Book your travel arrangements with us today and have left-over money to put toward your travel outings and adventures.

Frequently asked questions

How much is a flight from Sea-Tac Airport to Heathrow Airport (LHR)?
If you're traveling between SEA and London Heathrow, round-trip journeys start from ₩744,200. This price is based on fares listed within the last 7 days on Expedia for flights departing within the next year, so don't delay. Book today and save yourself money and time. 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 Heathrow Airport?
The majority of flights can be canceled online, but whether you are charged a fee all comes down to your airline. If you do need to cancel your trip, follow the instructions in the Customer Service Portal.
How do I find cheap flights from Seattle - Tacoma Intl. Airport (SEA) to LHR 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 Seattle - Tacoma Intl. Airport (SEA) to London Heathrow flights, you'll see a "no change fees" filter for you to select.
How far is the flight from Seattle - Tacoma Intl. Airport (SEA) to Heathrow Airport?
With a flight distance of 7,700 kilometers between Sea-Tac Airport and Heathrow Airport (LHR), this is a long trip. Be sure to drink plenty of water and go for a short walk down the aisle every now and then.
Which airlines fly direct from SEA to Heathrow Airport (LHR)?
It's easy to fly directly from Sea-Tac Airport to Heathrow Airport. Below are the most sought-after carriers that offer nonstop services on this route:

  • 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 to LHR flight tickets cheaper when they're purchased at the last minute?
Flight prices are constantly going up and down, so there are no guarantees. While last-minute deals between Seattle - Tacoma Intl. Airport (SEA) and Heathrow Airport are of course possible, it's also a good idea to keep track of prices well before you fly. In fact, some airlines announce their prices up to a year prior to the departure date. Expedia is constantly updating the best bargains around, so keep checking back and be ready to lock in your seat when the price dips.

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