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

As of September 2025, 21 flights take off from Seattle and land in London each day. The most common flight departure time for this route is 20:00, with 52% of daily flights taking off in the evening.

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

Flights via Reykjavik (KEF) offer the lowest average return price of £606.

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

WestJet is the most popular carrier operating from Seattle/Tacoma Intl to London

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

147 flights are operational weekly from Seattle to London as of September 2025. The most popular departure day for this route is Mon, with 14% of flights per week taking off on this day.

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 airlines fly to London?

Virgin Atlantic, British Airways and Icelandair 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 55% of people opting to fly with this airline when travelling to London. Keep in mind that there are 4 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 travel time from Seattle to London?

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

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 4 operators available for flights from Seattle/Tacoma Intl Airport to London as of September 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.

£195 Cheap Flights from Seattle to London in 2025/26

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15:45 - 22:30SEA-STN

22h 45m2 stops

08:15 - 20:40STN-SEA

20h 25m2 stops

£375

Find Deal

Wed, 1 Oct - Wed, 8 Oct

19:00 - 14:40SEA-LGW

11h 40m1 stop

11:55 - 17:00LGW-SEA

13h 05m1 stop

£375Icelandair

Find Deal

Fri, 24 Oct - Sun, 2 Nov

20:25 - 14:15SEA-LHR

9h 50mdirect

09:00 - 17:40LHR-SEA

16h 40m1 stop

£375Delta

Find Deal

Tue, 30 Sep - Thu, 9 Oct

16:48 - 10:30SEA-LHR

9h 42mdirect

06:20 - 11:25LHR-SEA

13h 05m1 stop

£376Delta

Find Deal

Wed, 12 Nov - Tue, 18 Nov

13:30 - 06:50SEA-LHR

9h 20mdirect

09:25 - 11:10LHR-SEA

9h 45mdirect

£377British Airways

Find Deal

Wed, 1 Oct - Tue, 14 Oct

07:15 - 06:30SEA-LHR

15h 15m1 stop

06:50 - 21:45LHR-SEA

22h 55m2 stops

£378Air Canada

Find Deal

Wed, 8 Oct - Tue, 14 Oct

05:50 - 07:10SEA-LHR

18h 20m2 stops

13:25 - 09:31LHR-SEA

28h 06m2 stops

£383Air Canada

Find Deal

Tue, 28 Oct - Tue, 4 Nov

07:48 - 06:50SEA-LHR

15h 02m1 stop

16:30 - 18:20LHR-SEA

9h 50mdirect

£393British Airways

Find Deal

Tue, 3 Mar - Wed, 15 Apr

15:05 - 16:35SEA-LCY

17h 30m1 stop

20:05 - 11:40LCY-SEA

23h 35m1 stop

£424Virgin Atlantic

Find Deal

Wed, 11 Feb - Tue, 17 Feb

15:05 - 17:20SEA-LCY

18h 15m1 stop

17:50 - 11:40LCY-SEA

25h 50m1 stop

£425Virgin Atlantic

Find Deal

Mon, 9 Feb - Mon, 16 Feb

SWISS flights from Seattle to London

Our best SWISS deals on Seattle to London flight tickets

SWISS

18 Nov

SEA13:20Seattle/Tacoma Intl

20h 30m

2 stops

LGW17:50London Gatwick

3 Dec

LGW18:40London Gatwick

36h 35m

2 stops

SEA23:15Seattle/Tacoma Intl

£394

Find similar

SWISS

8 Oct

SEA15:28Seattle/Tacoma Intl

18h 22m

2 stops

LHR17:50London Heathrow

21 Oct

LHR08:45London Heathrow

17h 51m

2 stops

SEA18:36Seattle/Tacoma Intl

£396

Find similar

SWISS

22 Sept

SEA15:19Seattle/Tacoma Intl

18h 31m

2 stops

LHR17:50London Heathrow

7 Oct

LHR08:45London Heathrow

17h 51m

2 stops

SEA18:36Seattle/Tacoma Intl

£397

Find similar

Delta flights from Seattle to London

Our best Delta deals on Seattle to London flight tickets

Delta

30 Sept

SEA20:25Seattle/Tacoma Intl

9h 50m

LHR14:15London Heathrow

9 Oct

LHR09:00London Heathrow

16h 40m

1 stop

SEA17:40Seattle/Tacoma Intl

£375

Find similar

Delta

12 Nov

SEA16:48Seattle/Tacoma Intl

9h 42m

LHR10:30London Heathrow

18 Nov

LHR06:20London Heathrow

13h 05m

1 stop

SEA11:25Seattle/Tacoma Intl

£376

Find similar

Delta

29 Sept

SEA17:35Seattle/Tacoma Intl

9h 45m

LHR11:20London Heathrow

10 Oct

LHR06:30London Heathrow

13h 20m

1 stop

SEA11:50Seattle/Tacoma Intl

£377

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Fly to

Route

Depart

Return

Price

SeattleLondon

SEA - STN

SEASTN

Seattle/Tacoma Intl

Wed 1/10

15:45-22:30

2 stops22h 45m

London Stansted

Wed 8/10

08:15-20:40

2 stops20h 25m

£375

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Fri 24/10

19:00-14:40

1 stop11h 40m

London Gatwick

Sun 2/11

11:55-17:00

1 stop13h 05m

£375

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 30/9

20:25-14:15

Nonstop9h 50m

London Heathrow

Thu 9/10

09:00-17:40

1 stop16h 40m

£375

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 12/11

16:48-10:30

Nonstop9h 42m

London Heathrow

Tue 18/11

06:20-11:25

1 stop13h 05m

£376

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 1/10

13:30-06:50

Nonstop9h 20m

London Heathrow

Tue 14/10

09:25-11:10

Nonstop9h 45m

£377

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 8/10

07:15-06:30

1 stop15h 15m

London Heathrow

Tue 14/10

06:50-21:45

2 stops22h 55m

£378

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 28/10

05:50-07:10

2 stops18h 20m

London Heathrow

Tue 4/11

13:25-09:31

2 stops28h 06m

£383

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 3/3

07:48-06:50

1 stop15h 02m

London Heathrow

Wed 15/4

16:30-18:20

Nonstop9h 50m

£393

SeattleLondon

SEA - LCY

SEALCY

Seattle/Tacoma Intl

Wed 11/2

15:05-16:35

1 stop17h 30m

London City

Tue 17/2

20:05-11:40

1 stop23h 35m

£424

SeattleLondon

SEA - LCY

SEALCY

Seattle/Tacoma Intl

Mon 9/2

15:05-17:20

1 stop18h 15m

London City

Mon 16/2

17:50-11:40

1 stop25h 50m

£425

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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 £487, 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 £498.

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 £500. 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 £678.

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 £577. Flights in the morning are often more expensive, with an average ticket price of £1,009.

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 £593 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 £521 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 September 2025, prices for Seattle to London flights are approximately 43% 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	£342
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 £342. The best return flight deal from Seattle to London found on momondo in the last 72 hours is £487.

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)

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 20m 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 4 operators available for flights from Seattle/Tacoma Intl Airport to London as of September 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 30.89% of the total bookings. Other popular models include Airbus A330-900neo with 21.16%, Boeing 787-9 Dreamliner with 11.12%, and Airbus A330-200 with 10.98%.
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 41% of the total bookings. Other popular airlines include British Airways with 19%, Icelandair with 19%, and KLM with 14%.

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 £345	Free Cancellation	Rating 7.2 1,270 reviews	Search Aer Lingus flights
British Airways	PriceFrom £349	Free Cancellation	Rating 6.6 7,361 reviews	Search British Airways flights
Virgin Atlantic	PriceFrom £364	Free Cancellation	Rating 7.4 664 reviews	Search Virgin Atlantic flights
Icelandair	PriceFrom £407	Free Cancellation	Rating 7.0 544 reviews	Search Icelandair flights

Virgin Atlantic Flights From Seattle to London
Virgin Atlantic flies from Seattle to London around 14 times per week, with 664 momondo users rating the airline 7.4/10. The cheapest Virgin Atlantic deal from Seattle to London in the last 72 hours was £494 (round-trip), much lower than the average airfare cost of £801 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, 1,271 ratings). Aer Lingus flies from Seattle to London around 14 times per week, with deals starting from £468 round-trip and rising to an average price of around £687.

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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 £195

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 8/3. 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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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 £500. 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 £678.

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 £577. Flights in the morning are often more expensive, with an average ticket price of £1,009.

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 September 2025, prices for Seattle to London flights are approximately 43% cheaper when compared to flights at the same time last year.

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

WestJet is the most popular carrier 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 £606.

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 September 2025, 21 flights take off from Seattle and land in London each day. The most common flight departure time for this route is 20:00, with 52% of daily flights taking off in the evening.

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

147 flights are operational weekly from Seattle to London as of September 2025. The most popular departure day for this route is Mon, with 14% 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