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Cheap flights from London Heathrow Airport to Seattle from £390

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 18/10. 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 (LHR-SEA)

Cheap return flights

United Airlines Logo
07:30 - 18:09LHR-SEA
18h 39m2 stops
United Airlines Logo
07:03 - 07:30SEA-LHR
16h 27m1 stop
£476United Airlines
Find Deal
lun., 9 févr. - ven., 13 févr.
Logo
06:30 - 14:16LHR-SEA
15h 46m2 stops
Logo
07:15 - 09:35SEA-LHR
18h 20m1 stop
£477
Find Deal
ven., 26 sept. - mer., 1 oct.
Icelandair Logo
13:05 - 17:50LHR-SEA
12h 45m1 stop
Icelandair Logo
15:45 - 11:55SEA-LHR
12h 10m1 stop
£480Icelandair
Find Deal
jeu., 9 oct. - ven., 24 oct.
Icelandair Logo
13:05 - 20:40LHR-SEA
15h 35m1 stop
Icelandair Logo
15:45 - 11:55SEA-LHR
12h 10m1 stop
£481Icelandair
Find Deal
jeu., 2 oct. - dim., 12 oct.
Lufthansa Logo
16:30 - 11:55LHR-SEA
27h 25m1 stop
Lufthansa Logo
07:00 - 08:20SEA-LHR
17h 20m1 stop
£482Lufthansa
Find Deal
sam., 20 sept. - ven., 17 oct.
Virgin Atlantic Logo
11:30 - 11:15LHR-SEA
31h 45m1 stop
Virgin Atlantic Logo
17:35 - 11:20SEA-LHR
9h 45mdirect
£483Virgin Atlantic
Find Deal
lun., 22 sept. - lun., 6 oct.
Virgin Atlantic Logo
19:45 - 11:15LHR-SEA
23h 30m1 stop
Virgin Atlantic Logo
17:35 - 11:20SEA-LHR
9h 45mdirect
£485Virgin Atlantic
Find Deal
lun., 22 sept. - lun., 6 oct.
Lufthansa Logo
06:30 - 12:10LHR-SEA
13h 40m1 stop
Lufthansa Logo
10:05 - 07:10SEA-LHR
37h 05m2 stops
£490Lufthansa
Find Deal
mar., 2 déc. - sam., 6 déc.
British Airways Logo
12:15 - 20:09LHR-SEA
15h 54m1 stop
British Airways Logo
10:32 - 09:00SEA-LHR
14h 28m1 stop
£499British Airways
Find Deal
lun., 22 sept. - mar., 14 oct.
British Airways Logo
14:55 - 16:55LHR-SEA
10h 00mdirect
British Airways Logo
11:45 - 11:35SEA-LHR
15h 50m1 stop
£502British Airways
Find Deal
lun., 1 déc. - mar., 9 déc.

Delta flights from London Heathrow Airport to Seattle

Our best Delta deals on London Heathrow Airport to Seattle flight tickets
Delta
22 Sept
LHR06:30London Heathrow
13h 15m
1 stop
SEA11:45Seattle/Tacoma Intl
6 Oct
SEA17:35Seattle/Tacoma Intl
9h 45m
LHR11:20London Heathrow
£498
Find similar
Delta
3 Sept
LHR08:40London Heathrow
15h 25m
1 stop
SEA16:05Seattle/Tacoma Intl
17 Sept
SEA17:35Seattle/Tacoma Intl
9h 45m
LHR11:20London Heathrow
£499
Find similar
Delta
22 Sept
LHR13:25London Heathrow
10h 05m
SEA15:30Seattle/Tacoma Intl
14 Oct
SEA17:35Seattle/Tacoma Intl
9h 45m
LHR11:20London Heathrow
£511
Find similar

Scandinavian Airlines flights from London Heathrow Airport to Seattle

Our best Scandinavian Airlines deals on London Heathrow Airport to Seattle flight tickets
Scandinavian Airlines
26 Sept
LHR06:40London Heathrow
15h 20m
2 stops
SEA14:00Seattle/Tacoma Intl
5 Oct
SEA16:20Seattle/Tacoma Intl
15h 40m
1 stop
LHR16:00London Heathrow
£507
Find similar
Scandinavian Airlines
4 Sept
LHR07:05London Heathrow
24h 10m
2 stops
SEA23:15Seattle/Tacoma Intl
8 Sept
SEA16:00Seattle/Tacoma Intl
16h 25m
2 stops
LHR16:25London Heathrow
£508
Find similar
Scandinavian Airlines
28 Aug
LHR19:30London Heathrow
26h 20m
1 stop
SEA13:50Seattle/Tacoma Intl
12 Sept
SEA16:20Seattle/Tacoma Intl
18h 10m
2 stops
LHR18:30London Heathrow
£526
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 21 août 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

lun. 9/2

07:30-18:09

2 stops18h 39m

Seattle/Tacoma Intl

ven. 13/2

07:03-07:30

1 stop16h 27m

£476

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

ven. 26/9

06:30-14:16

2 stops15h 46m

Seattle/Tacoma Intl

mer. 1/10

07:15-09:35

1 stop18h 20m

£477

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

jeu. 9/10

13:05-17:50

1 stop12h 45m

Seattle/Tacoma Intl

ven. 24/10

15:45-11:55

1 stop12h 10m

£480

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

jeu. 2/10

13:05-20:40

1 stop15h 35m

Seattle/Tacoma Intl

dim. 12/10

15:45-11:55

1 stop12h 10m

£481

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

sam. 20/9

16:30-11:55

1 stop27h 25m

Seattle/Tacoma Intl

ven. 17/10

07:00-08:20

1 stop17h 20m

£482

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

lun. 22/9

11:30-11:15

1 stop31h 45m

Seattle/Tacoma Intl

lun. 6/10

17:35-11:20

Nonstop9h 45m

£483

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

lun. 22/9

19:45-11:15

1 stop23h 30m

Seattle/Tacoma Intl

lun. 6/10

17:35-11:20

Nonstop9h 45m

£485

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

mar. 2/12

06:30-12:10

1 stop13h 40m

Seattle/Tacoma Intl

sam. 6/12

10:05-07:10

2 stops37h 05m

£490

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

lun. 22/9

12:15-20:09

1 stop15h 54m

Seattle/Tacoma Intl

mar. 14/10

10:32-09:00

1 stop14h 28m

£499

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

lun. 1/12

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

mar. 9/12

11:45-11:35

1 stop15h 50m

£502

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 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 £481, are often lower during this time because this is during the off-season. The month of November is another great option to travel to Seattle, with average flight prices from London Heathrow Airport averaging around £511.

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 £586. 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 £694.

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 £524. 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 afternoon are often more expensive, with an average ticket price of £626.

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 £574 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 £523 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?

No. A direct flight is the cheapest option for a flight between London Heathrow Airport to Seattle.

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

As of August 2025, prices for London Heathrow Airport to Seattle flights are approximately 21% cheaper 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

£640

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 £640. The best return flight deal from London Heathrow Airport to Seattle found on momondo in the last 72 hours is £535.
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 £354Free CancellationRating
7.0
528 reviews
Search Icelandair flights
Air FrancePriceFrom £384Free CancellationRating
7.4
1,469 reviews
Search Air France flights
LufthansaPriceFrom £394Free CancellationRating
6.8
7,344 reviews
Search Lufthansa flights
FinnairPriceFrom £402Free CancellationRating
7.6
1,320 reviews
Search Finnair flights
KLMPriceFrom £403Free CancellationRating
7.8
1,388 reviews
Search KLM flights
United AirlinesPriceFrom £404Free CancellationRating
7.4
8,930 reviews
Search United Airlines flights
British AirwaysPriceFrom £429Free CancellationRating
6.7
7,291 reviews
Search British Airways flights
Virgin AtlanticPriceFrom £442Free CancellationRating
7.4
658 reviews
Search Virgin Atlantic flights
DeltaPriceFrom £443Free CancellationRating
7.9
7,981 reviews
Search Delta flights
Air CanadaPriceFrom £462Free CancellationRating
7.1
10,000 reviews
Search Air Canada flights

  • Delta Flights From London Heathrow Airport to Seattle

    Delta operates around 12 flights from London Heathrow Airport to Seattle every week. The average price of these flights found in the last 72 hours has been £774, but momondo users have found Delta deals from London Heathrow Airport to Seattle from as low as £597 round-trip. Delta has been scored 7.9/10 in 7,981 reviews.

  • KLM Flights From London Heathrow Airport to Seattle

    KLM (7.8/10 from 1,388 reviews) operates around 12 flights from London Heathrow Airport to Seattle in any given week. The average KLM airfare for this route is around £762, with deals from around £543 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
Kent
SeaTac
Fife
Tukwila
Renton

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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