Cheap flights from Seattle to London from $348

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to London departing on 1/15. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Icelandair Logo
2:35 pm - 10:55 amSEA-LGW
12h 20m1 stop
Icelandair Logo
11:55 am - 5:00 pmLGW-SEA
13h 05m1 stop
$516Icelandair
Find Deal
Tue, Nov 18 - Tue, Nov 25
Multiple Airlines Logo
2:35 pm - 1:20 pmSEA-STN
14h 45m2 stops
Multiple Airlines Logo
6:30 am - 5:00 pmSTN-SEA
18h 30m2 stops
$517Multiple Airlines
Find Deal
Wed, Nov 12 - Wed, Nov 19
Icelandair Logo
2:35 pm - 10:55 amSEA-LGW
12h 20m1 stop
Icelandair Logo
11:55 am - 5:00 pmLGW-SEA
13h 05m1 stop
$517Icelandair
Find Deal
Sat, Nov 15 - Thu, Nov 20
Virgin Atlantic Logo
7:20 pm - 12:50 pmSEA-LHR
9h 30mnonstop
Virgin Atlantic Logo
2:45 pm - 4:50 pmLHR-SEA
10h 05mnonstop
$572Virgin Atlantic
Find Deal
Mon, Nov 3 - Tue, Nov 18
Delta Logo
4:48 pm - 10:30 amSEA-LHR
9h 42mnonstop
Delta Logo
6:20 am - 1:20 pmLHR-SEA
15h 00m1 stop
$577Delta
Find Deal
Tue, Nov 4 - Wed, Nov 19
Delta Logo
7:20 pm - 12:50 pmSEA-LHR
9h 30mnonstop
Delta Logo
6:30 am - 11:45 amLHR-SEA
13h 15m1 stop
$578Delta
Find Deal
Mon, Nov 3 - Wed, Nov 12
British Airways Logo
6:50 pm - 12:20 pmSEA-LHR
9h 30mnonstop
British Airways Logo
2:55 pm - 4:55 pmLHR-SEA
10h 00mnonstop
$579British Airways
Find Deal
Wed, Nov 12 - Thu, Nov 20
American Airlines Logo
6:50 pm - 12:20 pmSEA-LHR
9h 30mnonstop
American Airlines Logo
2:55 pm - 4:55 pmLHR-SEA
10h 00mnonstop
$584American Airlines
Find Deal
Mon, Nov 3 - Wed, Nov 19
British Airways Logo
6:50 pm - 12:20 pmSEA-LHR
9h 30mnonstop
British Airways Logo
9:25 am - 11:30 amLHR-SEA
10h 05mnonstop
$593British Airways
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Sun, Feb 22 - Fri, Mar 6
Virgin Atlantic Logo
3:00 pm - 6:25 pmSEA-LCY
19h 25m1 stop
Virgin Atlantic Logo
6:55 pm - 11:50 amLCY-SEA
24h 55m1 stop
$635Virgin Atlantic
Find Deal
Tue, Nov 18 - Tue, Dec 2

Lufthansa flights from Seattle to London

Our best Lufthansa deals on Seattle to London flight tickets
Lufthansa
Nov 11
SEA3:40 pmSeattle/Tacoma Intl
12h 10m
1 stop
LHR11:50 amLondon Heathrow
Nov 18
LHR7:40 amLondon Heathrow
19h 36m
2 stops
SEA7:16 pmSeattle/Tacoma Intl
Lufthansa
Dec 2
SEA3:40 pmSeattle/Tacoma Intl
12h 10m
1 stop
LHR11:50 amLondon Heathrow
Dec 11
LHR6:30 amLondon Heathrow
13h 40m
1 stop
SEA12:10 pmSeattle/Tacoma Intl
Lufthansa
Nov 19
SEA3:10 pmSeattle/Tacoma Intl
13h 50m
1 stop
LHR1:00 pmLondon Heathrow
Nov 25
LHR6:30 amLondon Heathrow
13h 40m
1 stop
SEA12:10 pmSeattle/Tacoma Intl

British Airways flights from Seattle to London

Our best British Airways deals on Seattle to London flight tickets
British Airways
Nov 12
SEA6:50 pmSeattle/Tacoma Intl
9h 30m
LHR12:20 pmLondon Heathrow
Nov 20
LHR2:55 pmLondon Heathrow
10h 00m
SEA4:55 pmSeattle/Tacoma Intl
British Airways
Feb 22
SEA6:50 pmSeattle/Tacoma Intl
9h 30m
LHR12:20 pmLondon Heathrow
Mar 6
LHR9:25 amLondon Heathrow
10h 05m
SEA11:30 amSeattle/Tacoma Intl

momondo Fare Finder

 
Customize your flight search to find flights from Seattle to London that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated October 16, 2025.
Use the filters below to find and compare flights from Seattle to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Tue 11/18

2:35 pm-10:55 am

1 stop12h 20m

London Gatwick

Tue 11/25

11:55 am-5:00 pm

1 stop13h 05m

$516

SeattleLondon

SEA - STN

SEASTN

Seattle/Tacoma Intl

Wed 11/12

2:35 pm-1:20 pm

2 stops14h 45m

London Stansted

Wed 11/19

6:30 am-5:00 pm

2 stops18h 30m

$517

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Sat 11/15

2:35 pm-10:55 am

1 stop12h 20m

London Gatwick

Thu 11/20

11:55 am-5:00 pm

1 stop13h 05m

$517

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 11/3

7:20 pm-12:50 pm

Nonstop9h 30m

London Heathrow

Tue 11/18

2:45 pm-4:50 pm

Nonstop10h 05m

$572

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 11/4

4:48 pm-10:30 am

Nonstop9h 42m

London Heathrow

Wed 11/19

6:20 am-1:20 pm

1 stop15h 00m

$577

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 11/3

7:20 pm-12:50 pm

Nonstop9h 30m

London Heathrow

Wed 11/12

6:30 am-11:45 am

1 stop13h 15m

$578

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 11/12

6:50 pm-12:20 pm

Nonstop9h 30m

London Heathrow

Thu 11/20

2:55 pm-4:55 pm

Nonstop10h 00m

$579

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 11/3

6:50 pm-12:20 pm

Nonstop9h 30m

London Heathrow

Wed 11/19

2:55 pm-4:55 pm

Nonstop10h 00m

$584

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 2/22

6:50 pm-12:20 pm

Nonstop9h 30m

London Heathrow

Fri 3/6

9:25 am-11:30 am

Nonstop10h 05m

$593

SeattleLondon

SEA - LCY

SEALCY

Seattle/Tacoma Intl

Tue 11/18

3:00 pm-6:25 pm

1 stop19h 25m

London City

Tue 12/2

6:55 pm-11:50 am

1 stop24h 55m

$635

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to London from

How to get the cheapest flight ticket from Seattle to London

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to London?

The cheapest month to fly to London from Seattle is in October. Flight prices, which tend to average around $663, are often lower during this time because this is during the off-season. The month of August is another great option to travel to London, with average flight prices from Seattle averaging around $677.

What is the cheapest day to depart on your flight to London?

The cheapest day to depart from Seattle to London is on a Tuesday. Travelers who choose to depart for London on a Tuesday will often find tickets for as low as $814. If your travel schedule is flexible, try to avoid departing on a Friday because tickets tend to average around $908. These prices are subject to change though, so be sure to set up a Price Alert for flights to London.

What is the cheapest time of day to depart on your flight to London?

Flying to London from Seattle in the evening is the least expensive time of day to depart. momondo users have found prices as low as $838 when looking at flights departing in the evening. Flights to London are more costly in the morning, with an average ticket price of $980. Departure times in the morning fall within the peak daily travel times, which is why tickets can be more expensive.

What is the cheapest Seattle/Tacoma Intl to London flight route?

Fly from Seattle/Tacoma Intl to London Heathrow for the best Seattle/Tacoma Intl - London flight prices

How far in advance should I book a flight to London?

You are more likely to see cheaper flights to London from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to London for around $804 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London from Seattle for as low as $705 on momondo.

What cabin class options are available on Seattle/Tacoma Intl to London flights?

There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to London flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have Seattle to London flight prices changed over time?

As of October 2025, prices for Seattle to London flights are approximately 36% cheaper when compared to flights at the same time last year.

When to book flights from Seattle to London

Are you open to changing your travel dates? Check out the ideal times to fly from Seattle to London according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Seattle to London (SEA to LON) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to London

Best Price Found

$414

Fastest flight time

9h 20m

Direct flights

Every day

Airports in London

1 airport
The best one-way flight to London from Seattle in the past 72 hours is $414. The best round-trip flight deal from Seattle to London found on momondo in the last 72 hours is $672.
The fastest flight from Seattle to London takes 9h 20m
Direct flights go from Seattle to London every day.
There is 1 airport near London: London Heathrow (LHR)
  • How far is Seattle/Tacoma Intl to London by plane?

    London is 4781.3 mi away from Seattle/Tacoma Intl. By plane, this route typically takes 9h 30m.

  • When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to London?

    Prices for flights from Seattle/Tacoma Intl Airport to London are refreshed on a daily basis.

  • How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to London?

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to London?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Seattle/Tacoma Intl Airport to London.

  • What documentation or ID do you need to fly to London?

    The travel and health documents you'll need for your trip to London may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at London. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from Seattle to London?

  • What is the most popular airline from Seattle to London?

Best airlines flying from Seattle to London

Compare and see reviews for airlines that fly from Seattle to London with momondo
Airline
Rating
Free Cancellation
Price
Scandinavian AirlinesPriceFrom $465Free CancellationRating
7.4
1,533 reviews
Search Scandinavian Airlines flights
IcelandairPriceFrom $484Free CancellationRating
7.0
556 reviews
Search Icelandair flights
Aer LingusPriceFrom $500Free CancellationRating
7.2
1,341 reviews
Search Aer Lingus flights
Air FrancePriceFrom $517Free CancellationRating
7.4
1,476 reviews
Search Air France flights
American AirlinesPriceFrom $532Free CancellationRating
7.2
11,040 reviews
Search American Airlines flights
United AirlinesPriceFrom $547Free CancellationRating
7.4
8,982 reviews
Search United Airlines flights
British AirwaysPriceFrom $547Free CancellationRating
6.7
7,457 reviews
Search British Airways flights
FinnairPriceFrom $556Free CancellationRating
7.6
1,332 reviews
Search Finnair flights
DeltaPriceFrom $561Free CancellationRating
7.9
7,978 reviews
Search Delta flights
IberiaPriceFrom $578Free CancellationRating
7.0
2,994 reviews
Search Iberia flights
  • Alaska Airlines Flights From Seattle to London

    Alaska Airlines flight deals from Seattle to London start from $853 round-trip. Over the 8 Alaska Airlines flights for this route in a normal week, average airfare is usually $1,082 round-trip - but some users have found much cheaper deals with momondo.

  • Delta Flights From Seattle to London

    Across 7,978 Delta reviews on momondo, the average score is 7.9/10. Delta flies from Seattle to London about 14 times each week, with ticket deals ranging from $561 to $841. Price data is based on momondo searches in the last 72 hours.

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Gatwick
Hounslow
Milton Keynes
Luton
Dover
Slough
Guildford
Dartford
Crawley
Hayes
Brentwood
Chelmsford
Colchester
Folkestone
Romford
Ilford
Cobham
Wembley
Stansted
Watford

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to London?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Seattle to London. momondo saves you time and could save you money on your trip.

Can I find flights from Seattle to London with flexible booking policies on momondo?

Yes. All flights to London from Seattle on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Seattle to London?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Seattle to London.

I’m not ready to book a flight from Seattle to London right now. Can momondo alert me if prices change?

If you are simply researching potential flights to London, momondo offers a useful price alert feature which will track prices for flights to London from Seattle and alert you when they change.

An easier way to manage your London trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Sat 11/15
Sat 11/22

Find better results for your trip to the United Kingdom

Fly into one of these airports located in London

Airports listed have a maximum distance of 35.6 mi from London