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Cheap flights from London Heathrow Airport to Seattle from £423

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from London Heathrow Airport to Seattle departing on 25/11. 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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Find the cheapest flights from London Heathrow Airport to Seattle

Cheap return flights

Enter your travel dates to find the best prices.
Icelandair Logo
20:35 - 17:00LHR-SEA
28h 25m1 stop
Icelandair Logo
14:35 - 19:30SEA-LHR
20h 55m1 stop
£452Icelandair
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Tue, 16 Dec - Wed, 14 Jan
Icelandair Logo
20:35 - 17:00LHR-SEA
28h 25m1 stop
Icelandair Logo
14:35 - 19:30SEA-LHR
20h 55m1 stop
£456Icelandair
Find Deal
Tue, 2 Dec - Tue, 9 Dec
Icelandair Logo
12:15 - 17:00LHR-SEA
12h 45m1 stop
Icelandair Logo
14:35 - 19:30SEA-LHR
20h 55m1 stop
£458Icelandair
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Wed, 26 Nov - Wed, 3 Dec
Virgin Atlantic Logo
06:20 - 12:25LHR-SEA
13h 05m1 stop
Virgin Atlantic Logo
17:40 - 10:30SEA-LHR
9h 50mdirect
£471Virgin Atlantic
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Tue, 10 Mar - Tue, 17 Mar
British Airways Logo
09:25 - 12:30LHR-SEA
10h 05mdirect
British Airways Logo
20:20 - 13:45SEA-LHR
9h 25mdirect
£476British Airways
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Sat, 21 Mar - Sat, 28 Mar
Virgin Atlantic Logo
06:20 - 12:25LHR-SEA
13h 05m1 stop
Virgin Atlantic Logo
20:20 - 12:50SEA-LHR
9h 30mdirect
£477Virgin Atlantic
Find Deal
Tue, 10 Mar - Tue, 17 Mar
Finnair Logo
14:55 - 16:55LHR-SEA
10h 00mdirect
Finnair Logo
07:00 - 12:00SEA-LHR
22h 00m1 stop
£479Finnair
Find Deal
Thu, 5 Mar - Tue, 10 Mar
British Airways Logo
14:55 - 16:55LHR-SEA
10h 00mdirect
British Airways Logo
13:44 - 11:35SEA-LHR
13h 51m1 stop
£482British Airways
Find Deal
Fri, 20 Feb - Tue, 24 Feb
Finnair Logo
17:00 - 23:25LHR-SEA
38h 25m2 stops
Finnair Logo
14:46 - 10:25SEA-LHR
35h 39m1 stop
£489Finnair
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Tue, 2 Dec - Sat, 6 Dec
Air France Logo
06:20 - 14:05LHR-SEA
14h 45m1 stop
Air France Logo
17:40 - 10:30SEA-LHR
9h 50mdirect
£496Air France
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Fri, 20 Mar - Fri, 27 Mar

Virgin Atlantic flights from London Heathrow Airport to Seattle

Our best Virgin Atlantic deals on London Heathrow Airport to Seattle flight tickets
Virgin Atlantic
10 Mar
LHR06:20London Heathrow
13h 05m
1 stop
SEA12:25Seattle/Tacoma Intl
17 Mar
SEA17:40Seattle/Tacoma Intl
9h 50m
LHR10:30London Heathrow
£471
Find similar
Virgin Atlantic
10 Mar
LHR06:20London Heathrow
13h 05m
1 stop
SEA12:25Seattle/Tacoma Intl
17 Mar
SEA20:20Seattle/Tacoma Intl
9h 30m
LHR12:50London Heathrow
£477
Find similar
Virgin Atlantic
10 Mar
LHR12:20London Heathrow
10h 20m
SEA15:40Seattle/Tacoma Intl
17 Mar
SEA17:40Seattle/Tacoma Intl
9h 50m
LHR10:30London Heathrow
£480
Find similar

Delta flights from London Heathrow Airport to Seattle

Our best Delta deals on London Heathrow Airport to Seattle flight tickets
Delta
8 Feb
LHR08:40London Heathrow
35h 00m
1 stop
SEA11:40Seattle/Tacoma Intl
18 Feb
SEA07:20Seattle/Tacoma Intl
15h 30m
1 stop
LHR06:50London Heathrow
£485
Find similar
Delta
23 Feb
LHR11:45London Heathrow
31h 55m
1 stop
SEA11:40Seattle/Tacoma Intl
4 Mar
SEA16:45Seattle/Tacoma Intl
9h 45m
LHR10:30London Heathrow
£496
Find similar
Delta
6 Nov
LHR06:30London Heathrow
13h 15m
1 stop
SEA11:45Seattle/Tacoma Intl
13 Nov
SEA16:48Seattle/Tacoma Intl
9h 42m
LHR10:30London Heathrow
£543
Find similar

momondo Fare Finder

 
Customise your flight search to find flights from London Heathrow Airport to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 279,928 searches. Data last updated 31 October 2025.
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 16/12

20:35-17:00

1 stop28h 25m

Seattle/Tacoma Intl

Wed 14/1

14:35-19:30

1 stop20h 55m

£452

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 2/12

20:35-17:00

1 stop28h 25m

Seattle/Tacoma Intl

Tue 9/12

14:35-19:30

1 stop20h 55m

£456

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 26/11

12:15-17:00

1 stop12h 45m

Seattle/Tacoma Intl

Wed 3/12

14:35-19:30

1 stop20h 55m

£458

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/3

06:20-12:25

1 stop13h 05m

Seattle/Tacoma Intl

Tue 17/3

17:40-10:30

Nonstop9h 50m

£471

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 21/3

09:25-12:30

Nonstop10h 05m

Seattle/Tacoma Intl

Sat 28/3

20:20-13:45

Nonstop9h 25m

£476

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/3

06:20-12:25

1 stop13h 05m

Seattle/Tacoma Intl

Tue 17/3

20:20-12:50

Nonstop9h 30m

£477

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 5/3

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Tue 10/3

07:00-12:00

1 stop22h 00m

£479

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 20/2

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Tue 24/2

13:44-11:35

1 stop13h 51m

£482

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 2/12

17:00-23:25

2 stops38h 25m

Seattle/Tacoma Intl

Sat 6/12

14:46-10:25

1 stop35h 39m

£489

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 20/3

06:20-14:05

1 stop14h 45m

Seattle/Tacoma Intl

Fri 27/3

17:40-10:30

Nonstop9h 50m

£496

Flights are sorted by cheapest return flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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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?

The cheapest month to fly to Seattle from London Heathrow Airport is in February. Flight prices, which tend to average around £492, are often lower during this time because this is during the off-season. The month of September is another great option to travel to Seattle, with average flight prices from London Heathrow Airport averaging around £522.

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

According to our data, Wednesday is the cheapest day to fly to Seattle from London Heathrow Airport. The lowest ticket price found for a Wednesday departure recently was £603. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. Be sure to avoid booking your departure on a Sunday as prices are generally higher than usual. According to our data, the average ticket price to Seattle on Sunday is £695.

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

According to our data, the cheapest time of day to fly to Seattle is in the evening. momondo users have found flights departing from London Heathrow Airport to Seattle in the evening for as low as £536. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the morning are often more expensive, with an average ticket price of £642.

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 £588 when searching weeks before you fly. 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 £551 on momondo.

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

There are 4 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 return 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

£517

Fastest flight time

9h 45m

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 £517. The best return flight deal from London Heathrow Airport to Seattle found on momondo in the last 72 hours is £553.
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?

    The distance between London Heathrow and Seattle/Tacoma Intl is about 4774.1 mi. A reasonable flight in good conditions will take 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 were last updated today.

  • How many operators does momondo search 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?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for 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 travel and health documents required for your trip to Seattle/Tacoma Intl Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Seattle/Tacoma Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

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

  • What is the most popular airline from London Heathrow Airport to Seattle?

Best airlines flying from London Heathrow Airport to Seattle

Compare and see reviews for airlines that fly from London Heathrow Airport to Seattle with momondo
Airline
Rating
Free Cancellation
Price
IcelandairPriceFrom £364Free CancellationRating
7.1
562 reviews
Search Icelandair flights
Air FrancePriceFrom £393Free CancellationRating
7.4
1,482 reviews
Search Air France flights
FinnairPriceFrom £405Free CancellationRating
7.6
1,333 reviews
Search Finnair flights
LufthansaPriceFrom £407Free CancellationRating
6.8
7,543 reviews
Search Lufthansa flights
KLMPriceFrom £411Free CancellationRating
7.7
1,406 reviews
Search KLM flights
United AirlinesPriceFrom £413Free CancellationRating
7.4
8,995 reviews
Search United Airlines flights
British AirwaysPriceFrom £448Free CancellationRating
6.7
7,489 reviews
Search British Airways flights
Virgin AtlanticPriceFrom £450Free CancellationRating
7.5
671 reviews
Search Virgin Atlantic flights
DeltaPriceFrom £453Free CancellationRating
7.9
7,997 reviews
Search Delta flights
Aer LingusPriceFrom £465Free CancellationRating
7.2
1,365 reviews
Search Aer Lingus flights

  • Delta Flights From London Heathrow Airport to Seattle

    Delta operates around 5 flights from London Heathrow Airport to Seattle every week. The average price of these flights found in the last 72 hours has been £615, but momondo users have found Delta deals from London Heathrow Airport to Seattle from as low as £453 round-trip. Delta has been scored 7.9/10 in 7,997 reviews.

  • KLM Flights From London Heathrow Airport to Seattle

    KLM (7.7/10 from 1,406 reviews) operates around 5 flights from London Heathrow Airport to Seattle in any given week. The average KLM airfare for this route is around £580, with deals from around £411 rare but found on momondo. Referenced prices are for round-trip London Heathrow Airport to Seattle flight searches in the last 72 hours.

Travelling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Fife
Renton
SeaTac

Why use momondo?

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

Finding the right flight to Seattle from London is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Seattle quick and easy, saving you time and money.

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

Flights from London to Seattle 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 London to Seattle?

Once all potential London to Seattle 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 London to Seattle right now. Can momondo alert me if prices change?

Of course. momondo tracks the price of London to Seattle flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

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