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

The number of flights available between London Heathrow Airport and Seattle is 5 per day as of October 2025. The most frequent departure time is 12:00p.m., with 78% of daily flights leaving in the afternoon.

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

The number of flights available between London Heathrow Airport and Seattle is 38 per week as of October 2025. The most frequent departure day is Thu, with 39% of weekly flights leaving on this day.

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

British Airways, United Airlines, and WestJet are the most popular carriers operating from London Heathrow to Seattle/Tacoma Intl

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

According to our data, Scandinavian Airlines has had the least delays on this route over the last 12 months, with about 4% of their flights experiencing any sort of delay.

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

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

How often are flights from London to Seattle delayed?

Historically, on average around 15% of flights between London and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 125 minutes.

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

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

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

Prices for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport are updated daily.

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

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 London Heathrow Airport to Seattle/Tacoma Intl Airport.

What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

The necessary travel and health documents for your Seattle/Tacoma Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

C$ 781 Cheap Flights from London Heathrow Airport to Seattle in 2025/26

Q: What is the typical price of a round-trip flight between London Heathrow Airport and Seattle?

Prices are currently low for flights on this route. Typical prices usually range from C$ 919 to C$ 1,127. The lowest price recently found on this route was C$ 874.

1 adult

Save money when you book flights with momondo

Big names, great deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Early arrival? Instantly customize your results

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

Find the cheapest flights from London Heathrow Airport to Seattle

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

12:15 p.m. - 6:00 p.m.LHR-SEA

12h 45m1 stop

3:45 p.m. - 11:55 a.m.SEA-LHR

12h 10m1 stop

C$ 874Icelandair

Find Deal

Thu, 19 Mar - Mon, 30 Mar

8:35 p.m. - 6:00 p.m.LHR-SEA

28h 25m1 stop

3:45 p.m. - 11:55 a.m.SEA-LHR

12h 10m1 stop

C$ 877Icelandair

Find Deal

Sat, 21 Mar - Mon, 30 Mar

8:40 a.m. - 11:40 a.m.LHR-SEA

35h 00m1 stop

7:20 a.m. - 6:50 a.m.SEA-LHR

15h 30m1 stop

C$ 892Delta

Find Deal

Sun, 8 Feb - Wed, 18 Feb

6:20 a.m. - 11:25 a.m.LHR-SEA

13h 05m1 stop

4:55 p.m. - 10:30 a.m.SEA-LHR

9h 35mdirect

C$ 899Delta

Find Deal

Sat, 7 Feb - Wed, 18 Feb

9:25 a.m. - 12:30 p.m.LHR-SEA

10h 05mdirect

2:35 p.m. - 7:10 a.m.SEA-LHR

9h 35mdirect

C$ 915British Airways

Find Deal

Sat, 21 Mar - Sat, 28 Mar

6:30 a.m. - 11:40 a.m.LHR-SEA

13h 10m1 stop

4:45 p.m. - 10:30 a.m.SEA-LHR

9h 45mdirect

C$ 924Multiple Airlines

Find Deal

Tue, 24 Feb - Sat, 7 Mar

4:40 p.m. - 1:20 p.m.LHR-SEA

28h 40m1 stop

5:00 a.m. - 9:40 a.m.SEA-LHR

20h 40m1 stop

C$ 929United Airlines

Find Deal

Tue, 10 Feb - Wed, 18 Feb

2:55 p.m. - 4:55 p.m.LHR-SEA

10h 00mdirect

1:39 p.m. - 11:35 a.m.SEA-LHR

13h 56m1 stop

C$ 930British Airways

Find Deal

Thu, 5 Feb - Fri, 20 Feb

6:30 a.m. - 12:10 p.m.LHR-SEA

13h 40m1 stop

10:55 a.m. - 7:55 a.m.SEA-LHR

13h 00m1 stop

C$ 931United Airlines

Find Deal

Mon, 9 Feb - Tue, 24 Feb

6:30 a.m. - 11:45 a.m.LHR-SEA

13h 15m1 stop

4:48 p.m. - 10:30 a.m.SEA-LHR

9h 42mdirect

C$ 1,005Multiple Airlines

Find Deal

Wed, 12 Nov - Wed, 19 Nov

Delta flights from London Heathrow Airport to Seattle

Our best Delta deals on London Heathrow Airport to Seattle flight tickets

Delta

8 Feb

LHR8:40 a.m.London Heathrow

35h 00m

1 stop

SEA11:40 a.m.Seattle/Tacoma Intl

18 Feb

SEA7:20 a.m.Seattle/Tacoma Intl

15h 30m

1 stop

LHR6:50 a.m.London Heathrow

C$ 892

Find similar

Delta

7 Feb

LHR6:20 a.m.London Heathrow

13h 05m

1 stop

SEA11:25 a.m.Seattle/Tacoma Intl

18 Feb

SEA4:55 p.m.Seattle/Tacoma Intl

9h 35m

LHR10:30 a.m.London Heathrow

C$ 899

Find similar

Delta

20 Mar

LHR6:20 a.m.London Heathrow

14h 45m

1 stop

SEA2:05 p.m.Seattle/Tacoma Intl

26 Mar

SEA8:20 p.m.Seattle/Tacoma Intl

9h 30m

LHR12:50 p.m.London Heathrow

C$ 910

Find similar

United Airlines flights from London Heathrow Airport to Seattle

Our best United Airlines deals on London Heathrow Airport to Seattle flight tickets

United Airlines

10 Feb

LHR4:40 p.m.London Heathrow

28h 40m

1 stop

SEA1:20 p.m.Seattle/Tacoma Intl

18 Feb

SEA5:00 a.m.Seattle/Tacoma Intl

20h 40m

1 stop

LHR9:40 a.m.London Heathrow

C$ 929

Find similar

United Airlines

9 Feb

LHR6:30 a.m.London Heathrow

13h 40m

1 stop

SEA12:10 p.m.Seattle/Tacoma Intl

24 Feb

SEA10:55 a.m.Seattle/Tacoma Intl

13h 00m

1 stop

LHR7:55 a.m.London Heathrow

C$ 931

Find similar

United Airlines

26 Nov

LHR7:30 a.m.London Heathrow

18h 40m

2 stops

SEA6:10 p.m.Seattle/Tacoma Intl

3 Dec

SEA7:00 a.m.Seattle/Tacoma Intl

15h 40m

2 stops

LHR6:40 a.m.London Heathrow

C$ 933

Find similar

momondo Fare Finder

Use the filters below to find and compare flights from London Heathrow Airport to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 19/3

12:15 p.m.-6:00 p.m.

1 stop12h 45m

Seattle/Tacoma Intl

Mon 30/3

3:45 p.m.-11:55 a.m.

1 stop12h 10m

C$ 874

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 21/3

8:35 p.m.-6:00 p.m.

1 stop28h 25m

Seattle/Tacoma Intl

Mon 30/3

3:45 p.m.-11:55 a.m.

1 stop12h 10m

C$ 877

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 8/2

8:40 a.m.-11:40 a.m.

1 stop35h 00m

Seattle/Tacoma Intl

Wed 18/2

7:20 a.m.-6:50 a.m.

1 stop15h 30m

C$ 892

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 7/2

6:20 a.m.-11:25 a.m.

1 stop13h 05m

Seattle/Tacoma Intl

Wed 18/2

4:55 p.m.-10:30 a.m.

Nonstop9h 35m

C$ 899

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 21/3

9:25 a.m.-12:30 p.m.

Nonstop10h 05m

Seattle/Tacoma Intl

Sat 28/3

2:35 p.m.-7:10 a.m.

Nonstop9h 35m

C$ 915

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 24/2

6:30 a.m.-11:40 a.m.

1 stop13h 10m

Seattle/Tacoma Intl

Sat 7/3

4:45 p.m.-10:30 a.m.

Nonstop9h 45m

C$ 924

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/2

4:40 p.m.-1:20 p.m.

1 stop28h 40m

Seattle/Tacoma Intl

Wed 18/2

5:00 a.m.-9:40 a.m.

1 stop20h 40m

C$ 929

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 5/2

2:55 p.m.-4:55 p.m.

Nonstop10h 00m

Seattle/Tacoma Intl

Fri 20/2

1:39 p.m.-11:35 a.m.

1 stop13h 56m

C$ 930

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 9/2

6:30 a.m.-12:10 p.m.

1 stop13h 40m

Seattle/Tacoma Intl

Tue 24/2

10:55 a.m.-7:55 a.m.

1 stop13h 00m

C$ 931

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 12/11

6:30 a.m.-11:45 a.m.

1 stop13h 15m

Seattle/Tacoma Intl

Wed 19/11

4:48 p.m.-10:30 a.m.

Nonstop9h 42m

C$ 1,005

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from London Heathrow Airport to Seattle

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 typical price of a round-trip flight between London Heathrow Airport and Seattle?

What is the cheapest month to fly to Seattle?

If you aren’t able to travel to Seattle during the month of February, then flying in September is also cheap. Prices for this month can be found on momondo for an average of C$ 961.

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

Our data shows that Monday is the least expensive day to fly to Seattle. Tickets to fly out on this day can be as low as C$ 1,066. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around C$ 1,612. These prices are subject to change though, so be sure to set up a Price Alert for flights to Seattle.

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

Our most recent data shows that the best time of day to fly to Seattle is in the afternoon. Flights from London Heathrow Airport to Seattle during this time can be as low as C$ 1,066. Flights at noon are often more expensive with an average ticket price of C$ 1,332.

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

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

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

You are more likely to see cheaper flights to Seattle from London Heathrow Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around C$ 1,083 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from London Heathrow Airport for as low as C$ 1,014 on momondo.

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

There are 3 cabin classes available to choose from on London Heathrow to Seattle/Tacoma Intl 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 London Heathrow Airport to Seattle flights?

You could potentially save up to 20% on your flight if you consider stops on a London Heathrow Airport to Seattle flight.

How have London Heathrow Airport to Seattle flight prices changed over time?

As of October 2025, prices for London Heathrow Airport to Seattle flights are approximately 22% more expensive when compared to flights at the same time last year.

When to book flights from London Heathrow Airport to Seattle

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

Estimated round-trip price

Cheap London Heathrow Airport to Seattle (LHR to SEA) flight deals and tips

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

Fastest flight time	9h 45m
Direct flights	Every day
Airports in Seattle	1 airport

The fastest flight from London Heathrow Airport to Seattle takes 9h 45m

Direct flights go from London Heathrow Airport to Seattle every day.

There is 1 airport near Seattle: Seattle/Tacoma Intl (SEA)

Search flight deals

How far is London Heathrow to Seattle/Tacoma Intl by plane?
London Heathrow and Seattle/Tacoma Intl are 7683.2 km apart from one another. By plane, this route typically takes 9h 45m.
When did momondo last update prices for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport?
Prices for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport are updated daily.
How old do you have to be to fly from London Heathrow Airport to Seattle/Tacoma Intl Airport?
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 London Heathrow Airport to Seattle/Tacoma Intl Airport.
What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?
The necessary travel and health documents for your Seattle/Tacoma Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from London Heathrow Airport to Seattle?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from London Heathrow Airport to Seattle is Boeing 787-9 Dreamliner (26.07% of total bookings). The next most popular plane models are Boeing 787-10 Dreamliner (23.56%), Airbus A330-900neo (21.66%), and Airbus A330-200 (9.88%).

Leavenworth

Lynnwood

Marysville

Tacoma

SeaTac

Kirkland

Olympia

Ocean Shores

Redmond

Shoreline

Ellensburg

Gig Harbor

Renton

Mukilteo

Cle Elum

Centralia

Federal Way

Puyallup

Shelton

Lakewood

Why use momondo?

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

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

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

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

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

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Seattle from London.

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

Yes momondo offers price alerts on flights to Seattle from London. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

An easier way to manage your Seattle 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.

Start using Trips

Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

1 adult

Sun 30/11

Sun 7/12

Email me momondo's favourite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States

Airports servicing Washington

Bellingham Airport

Wenatchee Pangborn Field Airport

Spokane Airport

Pasco Tri Cities Airport

Pullman Moscow Regional Airport

Popular Cities in the United States

Flights to Fort Lauderdalefrom C$ 149

Flights to Orlandofrom C$ 149

Flights to New Yorkfrom C$ 254

Flights to Las Vegasfrom C$ 141

Flights to Los Angelesfrom C$ 152

Flights to Miamifrom C$ 270

Flights to San Franciscofrom C$ 155

Flights to Honolulufrom C$ 327

Flights to Phoenixfrom C$ 163

Flights to Tampafrom C$ 225

Flights to Chicagofrom C$ 179

Flights to Houstonfrom C$ 223

Cheap flights from London Heathrow Airport to Seattle from C$ 781

Big names, great deals

Big names, great deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

Find the cheapest flights from London Heathrow Airport to Seattle

Cheap round-trip flights

Cheap one-way flights

Cheap last-minute flights

Cheap direct flights

Delta flights from London Heathrow Airport to Seattle

Our best Delta deals on London Heathrow Airport to Seattle flight tickets

United Airlines flights from London Heathrow Airport to Seattle

Our best United Airlines deals on London Heathrow Airport to Seattle flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from London Heathrow Airport to Seattle that are best for you.

See travel insights to Seattle from

How to get the cheapest flight ticket from London Heathrow Airport to Seattle

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 typical price of a round-trip flight between London Heathrow Airport and Seattle?

What is the cheapest month to fly to Seattle?

If you aren’t able to travel to Seattle during the month of February, then flying in September is also cheap. Prices for this month can be found on momondo for an average of C$ 961.

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

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

Our most recent data shows that the best time of day to fly to Seattle is in the afternoon. Flights from London Heathrow Airport to Seattle during this time can be as low as C$ 1,066. Flights at noon are often more expensive with an average ticket price of C$ 1,332.

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

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

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

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

There are 3 cabin classes available to choose from on London Heathrow to Seattle/Tacoma Intl 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 London Heathrow Airport to Seattle flights?

You could potentially save up to 20% on your flight if you consider stops on a London Heathrow Airport to Seattle flight.

How have London Heathrow Airport to Seattle flight prices changed over time?

As of October 2025, prices for London Heathrow Airport to Seattle flights are approximately 22% more expensive when compared to flights at the same time last year.

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

British Airways, United Airlines, and WestJet are the most popular carriers operating from London Heathrow to Seattle/Tacoma Intl

How often are flights from London to Seattle delayed?

Historically, on average around 15% of flights between London and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 125 minutes.

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

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

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

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

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

According to our data, Scandinavian Airlines has had the least delays on this route over the last 12 months, with about 4% of their flights experiencing any sort of delay.

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

The number of flights available between London Heathrow Airport and Seattle is 5 per day as of October 2025. The most frequent departure time is 12:00p.m., with 78% of daily flights leaving in the afternoon.

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

The number of flights available between London Heathrow Airport and Seattle is 38 per week as of October 2025. The most frequent departure day is Thu, with 39% of weekly flights leaving on this day.

When to book flights from London Heathrow Airport to Seattle

Cheap London Heathrow Airport to Seattle (LHR to SEA) flight deals and tips

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

Fastest flight time

Direct flights

Airports in Seattle

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

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

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

What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

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

Travelling to a place near Seattle?

Why use momondo?

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

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

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

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

An easier way to manage your Seattle 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.

Find better results for your trip to the United States

Airports servicing Washington