What is the cheapest airline that flies from Seattle/Tacoma Intl to London?

Icelandair, WestJet, and SWISS are the most popular carriers operating from Seattle/Tacoma Intl to London

What is the most punctual flight time for Seattle to London flights?

Generally, flights departing in the early afternoon tend to experience fewer delays. Flights departing at night have, in the past, seen delays more frequently in comparison.

How many flights depart from Seattle to London on average per week?

98 flights are operational weekly from Seattle to London as of December 2025. The most popular departure day for this route is Tue, with 21% of flights per week taking off on this day.

How often are flights from Seattle to London delayed?

Historically, on average around 16% of flights between Seattle and London have experienced a delay on any given week. The average delay length over the past 12 months has been 123 minutes.

How many flights depart from Seattle to London on average per day?

As of December 2025, 14 flights take off from Seattle and land in London each day. The most common flight departure time for this route is 16:00, with 61% of daily flights taking off in the afternoon.

What day of the week experiences the fewest flight delays on this route?

Tuesday is statistically the day of the week that experiences the fewest delays on this flight route. Sunday has historically seen more delays on average compared to the rest of the week.

Which airline has the best punctuality record on Seattle to London flights?

According to our data, Virgin Atlantic have had the fewest delays on this route over the last 12 months, with about 6% of their flights experiencing any sort of delay.

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 were last updated today.

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

There are 2 operators available for flights from Seattle/Tacoma Intl Airport to London as of December 2025.

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

Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to London.

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

The required travel and health documents for your London trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at London. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

£256 Cheap Flights from Seattle to London in 2025/26

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14:35 - 10:55

SEA

LGW

12h 20m1 stop

11:55 - 17:00

LGW

SEA

13h 05m1 stop

£432Icelandair

Sun, 11 Jan - Sun, 25 Jan

14:35 - 22:20

SEA

STN

23h 45m2 stops

05:55 - 17:00

STN

SEA

19h 05m2 stops

£433Multiple Airlines

Sat, 21 Feb - Sat, 28 Feb

14:35 - 10:50

SEA

LHR

12h 15m1 stop

20:35 - 17:00

LHR

SEA

28h 25m1 stop

£434Icelandair

Sun, 15 Feb - Mon, 23 Feb

10:58 - 07:55

SEA

LHR

12h 57m1 stop

06:50 - 20:57

LHR

SEA

22h 07m2 stops

£434Brussels Airlines

Wed, 14 Jan - Thu, 22 Jan

05:50 - 11:50

SEA

LHR

22h 00m1 stop

07:40 - 19:16

LHR

SEA

19h 36m2 stops

£435Multiple Airlines

Tue, 13 Jan - Sun, 18 Jan

15:40 - 11:55

SEA

LHR

12h 15m1 stop

13:05 - 17:55

LHR

SEA

12h 50m1 stop

£436Icelandair

Tue, 7 Apr - Fri, 17 Apr

09:55 - 10:10

SEA

LHR

16h 15m2 stops

07:40 - 19:16

LHR

SEA

19h 36m2 stops

£437Lufthansa

Wed, 14 Jan - Sun, 18 Jan

05:50 - 07:10

SEA

LHR

17h 20m2 stops

07:40 - 19:16

LHR

SEA

19h 36m2 stops

£439Lufthansa

Sun, 11 Jan - Sun, 18 Jan

15:10 - 16:35

SEA

LCY

17h 25m1 stop

20:05 - 11:50

LCY

SEA

23h 45m1 stop

£485Virgin Atlantic

Sun, 18 Jan - Sun, 25 Jan

15:05 - 19:35

SEA

LCY

20h 30m1 stop

13:45 - 12:35

LCY

SEA

29h 50m1 stop

£485Virgin Atlantic

Sun, 22 Feb - Sun, 8 Mar

Delta flights from Seattle to London

Our best Delta deals on Seattle to London flight tickets

Delta

13 Jan

SEA18:25Seattle/Tacoma Intl

9h 30m

LHR11:55London Heathrow

21 Jan

LHR10:00London Heathrow

33h 50m

1 stop

SEA11:50Seattle/Tacoma Intl

£460

Find similar

Delta

11 Jan

SEA22:55Seattle/Tacoma Intl

23h 30m

1 stop

LHR06:25London Heathrow

24 Jan

LHR06:30London Heathrow

13h 20m

1 stop

SEA11:50Seattle/Tacoma Intl

£461

Find similar

Delta

14 Mar

SEA11:46Seattle/Tacoma Intl

22h 04m

1 stop

LHR16:50London Heathrow

30 Mar

LHR11:45London Heathrow

32h 00m

1 stop

SEA11:45Seattle/Tacoma Intl

£463

Find similar

British Airways flights from Seattle to London

Our best British Airways deals on Seattle to London flight tickets

British Airways

13 Jan

SEA13:25Seattle/Tacoma Intl

9h 35m

LHR07:00London Heathrow

23 Jan

LHR09:25London Heathrow

10h 05m

SEA11:30Seattle/Tacoma Intl

£470

Find similar

British Airways

29 Dec

SEA20:05Seattle/Tacoma Intl

33h 30m

2 stops

LCY13:35London City

18 Jan

LCY15:30London City

38h 37m

2 stops

SEA22:07Seattle/Tacoma Intl

£753

Find similar

Fly from

Fly to

Route

Depart

Return

Price

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Sun 11/1

14:35-10:55

1 stop12h 20m

London Gatwick

Sun 25/1

11:55-17:00

1 stop13h 05m

£432

SeattleLondon

SEA - STN

SEASTN

Seattle/Tacoma Intl

Sat 21/2

14:35-22:20

2 stops23h 45m

London Stansted

Sat 28/2

05:55-17:00

2 stops19h 05m

£433

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 15/2

14:35-10:50

1 stop12h 15m

London Heathrow

Mon 23/2

20:35-17:00

1 stop28h 25m

£434

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 14/1

10:58-07:55

1 stop12h 57m

London Heathrow

Thu 22/1

06:50-20:57

2 stops22h 07m

£434

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 13/1

05:50-11:50

1 stop22h 00m

London Heathrow

Sun 18/1

07:40-19:16

2 stops19h 36m

£435

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 7/4

15:40-11:55

1 stop12h 15m

London Heathrow

Fri 17/4

13:05-17:55

1 stop12h 50m

£436

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 14/1

09:55-10:10

2 stops16h 15m

London Heathrow

Sun 18/1

07:40-19:16

2 stops19h 36m

£437

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 11/1

05:50-07:10

2 stops17h 20m

London Heathrow

Sun 18/1

07:40-19:16

2 stops19h 36m

£439

SeattleLondon

SEA - LCY

SEALCY

Seattle/Tacoma Intl

Sun 18/1

15:10-16:35

1 stop17h 25m

London City

Sun 25/1

20:05-11:50

1 stop23h 45m

£484

SeattleLondon

SEA - LCY

SEALCY

Seattle/Tacoma Intl

Sun 22/2

15:05-19:35

1 stop20h 30m

London City

Sun 8/3

13:45-12:35

1 stop29h 50m

£485

Flights are sorted by cheapest return flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

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

Prices

Airlines

Delays

Other information

What is the cheapest month to fly to London?

The cheapest month to fly to London from Seattle is in November. Flight prices, which tend to average around £483, are often lower during this time because this is during the off-season. The month of October is another great option to travel to London, with average flight prices from Seattle averaging around £484.

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

Our data shows that Tuesday is the least expensive day to fly to London. Tickets to fly out on this day can be as low as £515. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to London for around £657.

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

The cheapest time of day to fly to London is at midday when flights can be purchased for as low as £543. Flights in the morning are often more expensive, with an average ticket price of £1,023.

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 £594 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London from Seattle for as low as £517 on momondo.

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

There are 3 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.

Can stopping save me money on Seattle to London flights?

You could potentially save up to 25% on your flight if you consider stops on a Seattle to London flight.

How have Seattle to London flight prices changed over time?

As of December 2025, prices for Seattle to London flights are approximately 8% 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 return 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	£310
Fastest flight time	9h 15m
Direct flights	Every day
Airports in London	6 airports

The best one-way flight to London from Seattle in the past 72 hours is £310. The best return flight deal from Seattle to London found on momondo in the last 72 hours is £588.

The fastest flight from Seattle to London takes 9h 15m

Direct flights go from Seattle to London every day.

There are 6 airports in London. From Seattle there are direct flights to London Heathrow (LHR).

Search flight deals

How far is Seattle/Tacoma Intl to London by plane?
London is 4781.3 mi away from Seattle/Tacoma Intl. Typically, this will take 9h 15m by plane in normal conditions.
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 were last updated today.
How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to London?
There are 2 operators available for flights from Seattle/Tacoma Intl Airport to London as of December 2025.
How old do you have to be to fly from Seattle/Tacoma Intl Airport to London?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to London.
What documentation or ID do you need to fly to London?
The required travel and health documents for your London trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at London. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
What is the most popular plane model from Seattle to London?
Based on momondo bookings for flights between Seattle and London, the leading plane model is Boeing 787-10 Dreamliner, making up 25.70% of the total bookings. Other popular models include Boeing 787-9 Dreamliner with 25.09%, Airbus A330-200 with 20.71%, and Boeing 777 with 8.56%.
What is the most popular airline from Seattle to London?
Based on momondo bookings for flights between Seattle and London, the leading airline is Virgin Atlantic, making up 53% of the total bookings. Other popular airlines include British Airways with 18%, Icelandair with 16%, and KLM with 12%.

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
British Airways	PriceFrom £354	Free Cancellation	Rating 6.7 7,578 reviews		Search British Airways flights
Virgin Atlantic	PriceFrom £369	Free Cancellation	Rating 7.5 675 reviews		Search Virgin Atlantic flights

Virgin Atlantic Flights From Seattle to London
Virgin Atlantic flies from Seattle to London around 10 times per week, with 675 momondo users rating the airline 7.5/10. The cheapest Virgin Atlantic deal from Seattle to London in the last 72 hours was £369 (round-trip), much lower than the average airfare cost of £587 for Virgin Atlantic flights on this route.
British Airways Flights From Seattle to London
Another popular option for Seattle to London flights is British Airways (6.7/10, 7,579 ratings). British Airways flies from Seattle to London around 8 times per week, with deals starting from £354 round-trip and rising to an average price of around £521.

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Why use momondo?

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

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Seattle to London . Millions of users trust and use momondo every year so you are in good hands.

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

Flights from Seattle to London with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

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

Once all potential Seattle to London flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

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

Yes. momondo can track prices for Seattle to London flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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Cheap flights from Seattle to London from £256

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 13/1. 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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Our best British Airways deals on Seattle to London flight tickets

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See travel insights to London from

How to get the cheapest flight ticket from Seattle to London

What is the cheapest month to fly to London?

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

Our data shows that Tuesday is the least expensive day to fly to London. Tickets to fly out on this day can be as low as £515. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to London for around £657.

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

The cheapest time of day to fly to London is at midday when flights can be purchased for as low as £543. Flights in the morning are often more expensive, with an average ticket price of £1,023.

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?

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

There are 3 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.

Can stopping save me money on Seattle to London flights?

You could potentially save up to 25% on your flight if you consider stops on a Seattle to London flight.

How have Seattle to London flight prices changed over time?

As of December 2025, prices for Seattle to London flights are approximately 8% cheaper when compared to flights at the same time last year.

What is the cheapest airline that flies from Seattle/Tacoma Intl to London?

Icelandair, WestJet, and SWISS are the most popular carriers operating from Seattle/Tacoma Intl to London

How often are flights from Seattle to London delayed?

Historically, on average around 16% of flights between Seattle and London have experienced a delay on any given week. The average delay length over the past 12 months has been 123 minutes.

What is the most punctual flight time for Seattle to London flights?

Generally, flights departing in the early afternoon tend to experience fewer delays. Flights departing at night have, in the past, seen delays more frequently in comparison.

What day of the week experiences the fewest flight delays on this route?

Tuesday is statistically the day of the week that experiences the fewest delays on this flight route. Sunday has historically seen more delays on average compared to the rest of the week.

Which airline has the best punctuality record on Seattle to London flights?

According to our data, Virgin Atlantic have had the fewest delays on this route over the last 12 months, with about 6% of their flights experiencing any sort of delay.

How many flights depart from Seattle to London on average per day?

As of December 2025, 14 flights take off from Seattle and land in London each day. The most common flight departure time for this route is 16:00, with 61% of daily flights taking off in the afternoon.

How many flights depart from Seattle to London on average per week?

98 flights are operational weekly from Seattle to London as of December 2025. The most popular departure day for this route is Tue, with 21% of flights per week taking off on this day.

When to book flights from Seattle to London

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

Fastest flight time

Direct flights

Airports in London

How far is Seattle/Tacoma Intl to London by plane?

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

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?

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

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

Virgin Atlantic Flights From Seattle to London

British Airways Flights From Seattle to London

Travelling to a place near London?

Why use momondo?

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

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

How can momondo help me find flights 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?

An easier way to manage your London trip

We make it super easy to schedule, organise 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.

Find better results for your trip to the United Kingdom