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

As of October 2025, 5 flights take off from Seattle and land in London each day. The most common flight departure time for this route is 17:00, with 56% of daily flights taking off in the afternoon.

Which airlines fly to London?

Virgin Atlantic, British Airways and Aer Lingus are the top three most popular airlines that fly to London from Seattle according to our data. Virgin Atlantic is the first choice among our users, with 65% of people opting to fly with this airline when travelling to London. Keep in mind that there are 3 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.

Which airport is the most popular for stopovers for flights between Seattle and London?

Reykjavik (KEF) was the most common stop: 60% of momondo users choosing one-stop flights on this route connected there.

Which stopover airport has the shortest connection time from Seattle to London?

Reykjavik (KEF) has the shortest average stopover time for this route: 3h 22m.

Which stopover airport has the shortest travel time from Seattle to London?

Flights connecting via Vancouver (YVR) have the shortest average one-way travel time: 15h 35m.

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

40 flights are operational weekly from Seattle to London as of October 2025. The most popular departure day for this route is Thu, with 38% of flights per week taking off on this day.

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

British Airways, Air Canada, and Aer Lingus are the most popular carriers operating from Seattle/Tacoma Intl to London

Which stopover airport offers the lowest fares from Seattle to London?

Flights via Reykjavik (KEF) offer the lowest average return price of £624.

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 3 operators available for flights from Seattle/Tacoma Intl Airport to London as of October 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.

£279 Cheap Flights from Seattle to London in 2025/26

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15:35 - 19:30SEA-LHR

20h 55m1 stop

20:35 - 18:00LHR-SEA

28h 25m1 stop

£393Icelandair

Find Deal

Sun, 15 Mar - Wed, 25 Mar

14:35 - 10:50SEA-LHR

12h 15m1 stop

12:15 - 17:00LHR-SEA

12h 45m1 stop

£394Icelandair

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Sun, 15 Feb - Sun, 1 Mar

14:35 - 18:55SEA-LGW

20h 20m2 stops

08:50 - 17:00LGW-SEA

16h 10m2 stops

£395Multiple Airlines

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Wed, 12 Nov - Wed, 19 Nov

14:35 - 10:50SEA-LHR

12h 15m1 stop

12:15 - 17:00LHR-SEA

12h 45m1 stop

£395Icelandair

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Thu, 19 Feb - Tue, 24 Feb

14:35 - 17:05SEA-LTN

18h 30m2 stops

06:50 - 17:00LTN-SEA

18h 10m2 stops

£397Multiple Airlines

Find Deal

Wed, 12 Nov - Wed, 19 Nov

20:05 - 21:05SEA-LHR

17h 00m1 stop

08:50 - 18:20LHR-SEA

17h 30m1 stop

£416Aer Lingus

Find Deal

Mon, 1 Dec - Wed, 17 Dec

20:05 - 15:35SEA-LHR

11h 30m1 stop

12:10 - 18:20LHR-SEA

14h 10m1 stop

£423Aer Lingus

Find Deal

Mon, 24 Nov - Fri, 5 Dec

19:20 - 12:50SEA-LHR

9h 30mdirect

12:20 - 14:58LHR-SEA

10h 38mdirect

£430Virgin Atlantic

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Thu, 4 Dec - Sun, 14 Dec

16:48 - 10:30SEA-LHR

9h 42mdirect

12:20 - 14:58LHR-SEA

10h 38mdirect

£443Virgin Atlantic

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Wed, 10 Dec - Thu, 18 Dec

14:05 - 11:40SEA-LCY

13h 35m1 stop

10:00 - 15:50LCY-SEA

13h 50m1 stop

£542KLM

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Fri, 24 Apr - Thu, 7 May

Delta flights from Seattle to London

Our best Delta deals on Seattle to London flight tickets

Delta

2 Nov

SEA23:55Seattle/Tacoma Intl

23h 10m

1 stop

LHR07:05London Heathrow

18 Nov

LHR06:20London Heathrow

13h 05m

1 stop

SEA11:25Seattle/Tacoma Intl

£437

Find similar

Delta

12 Nov

SEA16:48Seattle/Tacoma Intl

9h 42m

LHR10:30London Heathrow

19 Nov

LHR06:20London Heathrow

15h 00m

1 stop

SEA13:20Seattle/Tacoma Intl

£438

Find similar

Delta

10 Dec

SEA16:48Seattle/Tacoma Intl

9h 42m

LHR10:30London Heathrow

25 Dec

LHR06:30London Heathrow

13h 20m

1 stop

SEA11:50Seattle/Tacoma Intl

£439

Find similar

SWISS flights from Seattle to London

Our best SWISS deals on Seattle to London flight tickets

SWISS

12 Nov

SEA15:37Seattle/Tacoma Intl

18h 13m

2 stops

LHR17:50London Heathrow

19 Nov

LHR09:00London Heathrow

21h 28m

2 stops

SEA22:28Seattle/Tacoma Intl

£448

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SWISS

10 Feb

SEA10:58Seattle/Tacoma Intl

22h 52m

2 stops

LGW17:50London Gatwick

18 Feb

LGW18:40London Gatwick

36h 03m

2 stops

SEA22:43Seattle/Tacoma Intl

£450

Find similar

SWISS

5 Nov

SEA14:40Seattle/Tacoma Intl

19h 10m

2 stops

LHR17:50London Heathrow

12 Nov

LHR09:00London Heathrow

21h 28m

2 stops

SEA22:28Seattle/Tacoma Intl

£463

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Fly from

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Route

Depart

Return

Price

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 15/3

15:35-19:30

1 stop20h 55m

London Heathrow

Wed 25/3

20:35-18:00

1 stop28h 25m

£393

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 15/2

14:35-10:50

1 stop12h 15m

London Heathrow

Sun 1/3

12:15-17:00

1 stop12h 45m

£394

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Wed 12/11

14:35-18:55

2 stops20h 20m

London Gatwick

Wed 19/11

08:50-17:00

2 stops16h 10m

£395

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 19/2

14:35-10:50

1 stop12h 15m

London Heathrow

Tue 24/2

12:15-17:00

1 stop12h 45m

£395

SeattleLondon

SEA - LTN

SEALTN

Seattle/Tacoma Intl

Wed 12/11

14:35-17:05

2 stops18h 30m

London Luton

Wed 19/11

06:50-17:00

2 stops18h 10m

£397

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 1/12

20:05-21:05

1 stop17h 00m

London Heathrow

Wed 17/12

08:50-18:20

1 stop17h 30m

£416

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 24/11

20:05-15:35

1 stop11h 30m

London Heathrow

Fri 5/12

12:10-18:20

1 stop14h 10m

£423

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 4/12

19:20-12:50

Nonstop9h 30m

London Heathrow

Sun 14/12

12:20-14:58

Nonstop10h 38m

£430

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 10/12

16:48-10:30

Nonstop9h 42m

London Heathrow

Thu 18/12

12:20-14:58

Nonstop10h 38m

£443

SeattleLondon

SEA - LCY

SEALCY

Seattle/Tacoma Intl

Fri 24/4

14:05-11:40

1 stop13h 35m

London City

Thu 7/5

10:00-15:50

1 stop13h 50m

£542

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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

Stopovers

Other information

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 £503, are often lower during this time because this is during the off-season. The month of March is another great option to travel to London, with average flight prices from Seattle averaging around £515.

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 £521. When flying out on a Friday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to London for around £669.

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 £594. Flights in the morning are often more expensive, with an average ticket price of £1,039.

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 £609 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 £535 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.

How have Seattle to London flight prices changed over time?

As of October 2025, prices for Seattle to London flights are approximately 35% 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	£466
Fastest flight time	9h 15m
Direct flights	Every day
Airports in London	1 airport

The best one-way flight to London from Seattle in the past 72 hours is £466. The best return flight deal from Seattle to London found on momondo in the last 72 hours is £495.

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

Direct flights go from Seattle to London every day.

There is 1 airport near London: 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 30m 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 3 operators available for flights from Seattle/Tacoma Intl Airport to London as of October 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 25.94% of the total bookings. Other popular models include Airbus A330-200 with 15.50%, Boeing 787-9 Dreamliner with 13.41%, and Airbus A330-900neo with 13.00%.
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 47% of the total bookings. Other popular airlines include Icelandair with 21%, British Airways with 20%, 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
Aer Lingus	PriceFrom £355	Free Cancellation	Rating 7.2 1,361 reviews	Search Aer Lingus flights
British Airways	PriceFrom £360	Free Cancellation	Rating 6.7 7,487 reviews	Search British Airways flights
Virgin Atlantic	PriceFrom £375	Free Cancellation	Rating 7.5 670 reviews	Search Virgin Atlantic flights

Virgin Atlantic Flights From Seattle to London
Virgin Atlantic flies from Seattle to London around 4 times per week, with 670 momondo users rating the airline 7.5/10. The cheapest Virgin Atlantic deal from Seattle to London in the last 72 hours was £375 (round-trip), much lower than the average airfare cost of £626 for Virgin Atlantic flights on this route.
Aer Lingus Flights From Seattle to London
Another popular option for Seattle to London flights is Aer Lingus (7.2/10, 1,361 ratings). Aer Lingus flies from Seattle to London around 6 times per week, with deals starting from £355 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 £279

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 14/12. 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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Delta flights from Seattle to London

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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?

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 £521. When flying out on a Friday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to London for around £669.

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 £594. Flights in the morning are often more expensive, with an average ticket price of £1,039.

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.

How have Seattle to London flight prices changed over time?

As of October 2025, prices for Seattle to London flights are approximately 35% cheaper when compared to flights at the same time last year.

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

British Airways, Air Canada, and Aer Lingus are the most popular carriers operating from Seattle/Tacoma Intl to London

Which airlines fly to London?

Which airport is the most popular for stopovers for flights between Seattle and London?

Reykjavik (KEF) was the most common stop: 60% of momondo users choosing one-stop flights on this route connected there.

Which stopover airport offers the lowest fares from Seattle to London?

Flights via Reykjavik (KEF) offer the lowest average return price of £624.

Which stopover airport has the shortest travel time from Seattle to London?

Flights connecting via Vancouver (YVR) have the shortest average one-way travel time: 15h 35m.

Which stopover airport has the shortest connection time from Seattle to London?

Reykjavik (KEF) has the shortest average stopover time for this route: 3h 22m.

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

As of October 2025, 5 flights take off from Seattle and land in London each day. The most common flight departure time for this route is 17:00, with 56% of daily flights taking off in the afternoon.

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

40 flights are operational weekly from Seattle to London as of October 2025. The most popular departure day for this route is Thu, with 38% 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

Aer Lingus 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