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 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 10 per day as of January 2026. The most frequent departure time is 2:00p.m., with 81% of daily flights leaving in the afternoon.

How often are flights from London to Seattle delayed?

Historically, on average around 12% 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 128 minutes.

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

United Airlines, Icelandair, and SWISS 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, Delta has had the least delays on this route over the last 12 months, with about 5% of their flights experiencing any sort of delay.

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 74 per week as of January 2026. The most frequent departure day is Thu, with 20% of weekly flights leaving on this day.

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

Thursday is statistically the day of the week that experiences the fewest delays on this flight route. Monday 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$ 654 Cheap Flights from London Heathrow Airport to Seattle in 2026

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$ 759 to C$ 1,029. The lowest price recently found on this route was C$ 654.

1 adult

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Find the cheapest flights from London Heathrow Airport to Seattle

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One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

8:35 p.m. - 5:00 p.m.

LHR

SEA

28h 25m

1 stop

3:00 p.m. - 10:50 a.m.

SEA

LHR

12h 50m

1 stop

C$ 654Icelandair

Tue, 24 Feb - Sun, 8 Mar

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

LHR

SEA

28h 25m

1 stop

3:40 p.m. - 11:55 a.m.

SEA

LHR

12h 15m

1 stop

C$ 672Icelandair

Tue, 24 Mar - Mon, 30 Mar

6:35 a.m. - 2:20 p.m.

LHR

SEA

14h 45m

1 stop

12:25 p.m. - 9:10 a.m.

SEA

LHR

13h 45m

1 stop

C$ 684United Airlines

Fri, 13 Mar - Fri, 20 Mar

6:35 a.m. - 2:20 p.m.

LHR

SEA

14h 45m

1 stop

12:25 p.m. - 9:10 a.m.

SEA

LHR

13h 45m

1 stop

C$ 686United Airlines

Fri, 13 Mar - Fri, 20 Mar

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

LHR

SEA

13h 40m

1 stop

3:40 p.m. - 11:50 a.m.

SEA

LHR

12h 10m

1 stop

C$ 687Lufthansa

Thu, 12 Feb - Sun, 22 Feb

6:35 a.m. - 2:20 p.m.

LHR

SEA

14h 45m

1 stop

11:59 p.m. - 9:20 p.m.

SEA

LHR

14h 21m

1 stop

C$ 690United Airlines

Fri, 13 Mar - Fri, 20 Mar

6:35 a.m. - 9:14 p.m.

LHR

SEA

21h 39m

2 stops

8:45 a.m. - 1:30 p.m.

SEA

LHR

21h 45m

1 stop

C$ 692United Airlines

Wed, 18 Mar - Sun, 22 Mar

6:50 a.m. - 7:03 p.m.

LHR

SEA

20h 13m

2 stops

8:59 a.m. - 7:55 a.m.

SEA

LHR

14h 56m

2 stops

C$ 695United Airlines

Sat, 28 Feb - Thu, 5 Mar

6:50 a.m. - 7:03 p.m.

LHR

SEA

19h 13m

2 stops

12:25 p.m. - 9:10 a.m.

SEA

LHR

13h 45m

1 stop

C$ 696United Airlines

Fri, 13 Mar - Fri, 20 Mar

6:30 a.m. - 1:10 p.m.

LHR

SEA

13h 40m

1 stop

6:20 a.m. - 11:35 a.m.

SEA

LHR

21h 15m

2 stops

C$ 698United Airlines

Thu, 19 Mar - Wed, 1 Apr

Icelandair flights from London Heathrow Airport to Seattle

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

Icelandair

24 Feb

LHR8:35 p.m.London Heathrow

28h 25m

1 stop

SEA5:00 p.m.Seattle/Tacoma Intl

8 Mar

SEA3:00 p.m.Seattle/Tacoma Intl

12h 50m

1 stop

LHR10:50 a.m.London Heathrow

C$ 654

Icelandair

24 Mar

LHR8:35 p.m.London Heathrow

28h 25m

1 stop

SEA6:00 p.m.Seattle/Tacoma Intl

30 Mar

SEA3:40 p.m.Seattle/Tacoma Intl

12h 15m

1 stop

LHR11:55 a.m.London Heathrow

C$ 672

Icelandair

10 Mar

LHR12:15 p.m.London Heathrow

12h 45m

1 stop

SEA6:00 p.m.Seattle/Tacoma Intl

17 Mar

SEA3:35 p.m.Seattle/Tacoma Intl

12h 15m

1 stop

LHR10:50 a.m.London Heathrow

C$ 699

United Airlines flights from London Heathrow Airport to Seattle

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

United Airlines

13 Mar

LHR6:35 a.m.London Heathrow

14h 45m

1 stop

SEA2:20 p.m.Seattle/Tacoma Intl

20 Mar

SEA12:25 p.m.Seattle/Tacoma Intl

13h 45m

1 stop

LHR9:10 a.m.London Heathrow

C$ 684

United Airlines

13 Mar

LHR6:35 a.m.London Heathrow

14h 45m

1 stop

SEA2:20 p.m.Seattle/Tacoma Intl

20 Mar

SEA12:25 p.m.Seattle/Tacoma Intl

13h 45m

1 stop

LHR9:10 a.m.London Heathrow

C$ 686

United Airlines

13 Mar

LHR6:35 a.m.London Heathrow

14h 45m

1 stop

SEA2:20 p.m.Seattle/Tacoma Intl

20 Mar

SEA11:59 p.m.Seattle/Tacoma Intl

14h 21m

1 stop

LHR9:20 p.m.London Heathrow

C$ 690

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

Tue 24/2

8:35 p.m.-5:00 p.m.

1 stop28h 25m

Seattle/Tacoma Intl

Sun 8/3

3:00 p.m.-10:50 a.m.

1 stop12h 50m

C$ 654

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 24/3

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

1 stop28h 25m

Seattle/Tacoma Intl

Mon 30/3

3:40 p.m.-11:55 a.m.

1 stop12h 15m

C$ 672

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 13/3

6:35 a.m.-2:20 p.m.

1 stop14h 45m

Seattle/Tacoma Intl

Fri 20/3

12:25 p.m.-9:10 a.m.

1 stop13h 45m

C$ 684

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 13/3

6:35 a.m.-2:20 p.m.

1 stop14h 45m

Seattle/Tacoma Intl

Fri 20/3

12:25 p.m.-9:10 a.m.

1 stop13h 45m

C$ 686

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 12/2

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

1 stop13h 40m

Seattle/Tacoma Intl

Sun 22/2

3:40 p.m.-11:50 a.m.

1 stop12h 10m

C$ 687

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 13/3

6:35 a.m.-2:20 p.m.

1 stop14h 45m

Seattle/Tacoma Intl

Fri 20/3

11:59 p.m.-9:20 p.m.

1 stop14h 21m

C$ 690

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 18/3

6:35 a.m.-9:14 p.m.

2 stops21h 39m

Seattle/Tacoma Intl

Sun 22/3

8:45 a.m.-1:30 p.m.

1 stop21h 45m

C$ 692

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 28/2

6:50 a.m.-7:03 p.m.

2 stops20h 13m

Seattle/Tacoma Intl

Thu 5/3

8:59 a.m.-7:55 a.m.

2 stops14h 56m

C$ 695

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 13/3

6:50 a.m.-7:03 p.m.

2 stops19h 13m

Seattle/Tacoma Intl

Fri 20/3

12:25 p.m.-9:10 a.m.

1 stop13h 45m

C$ 696

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 19/3

6:30 a.m.-1:10 p.m.

1 stop13h 40m

Seattle/Tacoma Intl

Wed 1/4

6:20 a.m.-11:35 a.m.

2 stops21h 15m

C$ 698

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 January is also cheap. Prices for this month can be found on momondo for an average of C$ 924.

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$ 1,036. If your travel schedule is flexible, try to avoid departing on a Thursday because tickets tend to average around C$ 1,283. 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$ 1,029. Flights at noon are often more expensive with an average ticket price of C$ 1,295.

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$ 1,020 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$ 953 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 January 2026, prices for London Heathrow Airport to Seattle flights are approximately 1% 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

Best price found	C$ 1,142
Fastest flight time	10h 00m
Direct flights	Every day
Airports in Seattle	1 airport

The best one-way flight to Seattle from London Heathrow Airport in the past 72 hours is C$ 1,142. The best round-trip flight deal from London Heathrow Airport to Seattle found on momondo in the last 72 hours is C$ 1,035.

The fastest flight from London Heathrow Airport to Seattle takes 10h 00m

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

There is 1 airport in Seattle. From London Heathrow Airport there are direct flights to 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 10h 00m.
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 (27.39% of total bookings). The next most popular plane models are Boeing 787-10 Dreamliner (17.87%), Boeing 777-300ER (12.01%), and Airbus A330-900neo (11.60%).

Lynnwood

Leavenworth

Tacoma

Marysville

SeaTac

Redmond

Kirkland

Tukwila

Olympia

Ocean Shores

Bainbridge Island

Ellensburg

Gig Harbor

Renton

Mukilteo

Cle Elum

Centralia

Puyallup

Kent

Edmonds

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.

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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.

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Sat 28/2

Sat 7/3

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Cheap flights from London Heathrow Airport to Seattle from C$ 654

Big names, great deals

Big names, great deals

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Filter for what you want

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Find the cheapest flights from London Heathrow Airport to Seattle

Cheap round-trip flights

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Cheap direct flights

Icelandair flights from London Heathrow Airport to Seattle

Our best Icelandair 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

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 January is also cheap. Prices for this month can be found on momondo for an average of C$ 924.

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$ 1,029. Flights at noon are often more expensive with an average ticket price of C$ 1,295.

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 January 2026, prices for London Heathrow Airport to Seattle flights are approximately 1% 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?

United Airlines, Icelandair, and SWISS 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 12% 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 128 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?

Thursday is statistically the day of the week that experiences the fewest delays on this flight route. Monday 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, Delta has had the least delays on this route over the last 12 months, with about 5% 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 10 per day as of January 2026. The most frequent departure time is 2:00p.m., with 81% 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 74 per week as of January 2026. The most frequent departure day is Thu, with 20% 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

Best price found

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