S$413 Cheap Flights from Seattle to London

View S$413 flight on Mon, 13 Oct, 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 S$413 for one-way flights and S$720 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Virgin Atlantic
Fri, 5 Sep - Fri, 12 Sep
SEA
Seattle
LHR
London
S$720 Return, found 3 days ago
S$720
Return
found 3 days ago
Select Virgin Atlantic flight, departing Fri, 5 Sep from Seattle to London, returning Fri, 12 Sep, priced at S$720 found 3 days ago
Delta
Fri, 5 Sep - Fri, 12 Sep
SEA
Seattle
LHR
London
S$736 Return, found 3 days ago
S$736
Return
found 3 days ago
Select Delta flight, departing Fri, 5 Sep from Seattle to London, returning Fri, 12 Sep, priced at S$736 found 3 days ago
KLM
Fri, 5 Sep - Fri, 12 Sep
SEA
Seattle
LHR
London
S$754 Return, found 3 days ago
S$754
Return
found 3 days ago
Select KLM flight, departing Fri, 5 Sep from Seattle to London, returning Fri, 12 Sep, priced at S$754 found 3 days ago
Delta
Fri, 5 Sep - Fri, 12 Sep
SEA
Seattle
LHR
London
S$762 Return, found 3 days ago
S$762
Return
found 3 days ago
Select Delta flight, departing Fri, 5 Sep from Seattle to London, returning Fri, 12 Sep, priced at S$762 found 3 days ago
Delta
Fri, 5 Sep - Fri, 12 Sep
SEA
Seattle
LHR
London
S$769 Return, found 3 days ago
S$769
Return
found 3 days ago
Select Delta flight, departing Fri, 5 Sep from Seattle to London, returning Fri, 12 Sep, priced at S$769 found 3 days ago
KLM
Fri, 5 Sep - Fri, 12 Sep
SEA
Seattle
LHR
London
S$795 Return, found 3 days ago
S$795
Return
found 3 days ago
Select KLM flight, departing Fri, 5 Sep from Seattle to London, returning Fri, 12 Sep, priced at S$795 found 3 days ago
Delta
Fri, 19 Sep - Tue, 23 Sep
SEA
Seattle
LHR
London
S$861 Return, found 18 hours ago
S$861
Return
found 18 hours ago
Select Delta flight, departing Fri, 19 Sep from Seattle to London, returning Tue, 23 Sep, priced at S$861 found 18 hours ago
Virgin Atlantic
Fri, 19 Sep - Tue, 23 Sep
SEA
Seattle
LHR
London
S$870 Return, found 18 hours ago
S$870
Return
found 18 hours ago
Select Virgin Atlantic flight, departing Fri, 19 Sep from Seattle to London, returning Tue, 23 Sep, priced at S$870 found 18 hours ago
Finnair
Fri, 5 Sep - Fri, 12 Sep
SEA
Seattle
LHR
London
S$993 Return, found 3 days ago
S$993
Return
found 3 days ago
Select Finnair flight, departing Fri, 5 Sep from Seattle to London, returning Fri, 12 Sep, priced at S$993 found 3 days ago
American Airlines
Fri, 5 Sep - Fri, 12 Sep
SEA
Seattle
LHR
London
S$993 Return, found 3 days ago
S$993
Return
found 3 days ago
Select American Airlines flight, departing Fri, 5 Sep from Seattle to London, returning Fri, 12 Sep, priced at S$993 found 3 days ago

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

October is typically the cheapest month to fly

From S$614 - S$1,110 per traveller.

Graph displaying average flight prices per month

Seattle to London route information
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, KLM, Lufthansa, United, Virgin Atlantic, WestJet
Return price
S$720
Distance
7657 km
Average flight time
17 hours 33 mins

Flights from Seattle to London

There are several airlines that operate frequent flights from Seattle (SEA) to London (LHR) including

The earliest flight leaves Seattle Tacoma Intl. Airport at 13:15 and arrives at Heathrow Airport at 06:45. The last flight of the day departs Seattle at 20:37 and arrives at London at 13:35.

The flight distance from Seattle to London is about 7743 km, the shortest flight is 09 hours with WestJet.

Expedia lets you search across the largest number of airlines and London flights, which means that you’ll be able to find a great flight deal at the perfect travel date and time. Our simple-to-use booking engine makes looking for terrific bargains easy and hassle-free; just enter your travel dates and departure city, and let Expedia do the rest! Adjust your travel dates and explore connecting flights to find an even better deal on your Seattle London flight!

Browse through dozens of options and rest assured that you’re seeing the best price guaranteed! Our friendly customer service representatives are here to serve you 24 hours day to provide assistance and answer any questions that you may have about booking your Seattle to London trip. There’s simply no substitute for great prices suited to your travel needs and backed by excellent customer support.

Combine your London flight with a hotel and/or car rental for a package deal designed to save you even more money! Discover additional savings by booking in advance or find a last minute deal. There are tons of ways to save on your flights from Seattle to London with Expedia. Use us as your stop travel destination and have the confidence that you’re getting a bargain!

Frequently asked questions

How much is a flight from Sea-Tac Airport to Heathrow Airport (LHR)?
If you're travelling between SEA and London Heathrow, round-trip journeys start from S$720. 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 cancelled 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 kilometres 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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