$298 Cheap Flights from Seattle (SEA) to London (LON)

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 $298 for one-way flights and $397 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Icelandair
KLM
KLM
KLM
Aer Lingus
United
Virgin Atlantic
American Airlines
Lufthansa
American Airlines

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

October is typically the cheapest month to fly

From $482 - $933 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.

Flights from Seattle (SEA) to London (LGW)
Origin airport
Seattle - Tacoma Intl.
Destination airport
Gatwick
Roundtrip price
$396
Distance
4810 mi

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 $298 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 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 $397. 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 canceled 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 4786 mi 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.

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