Cheap flights from London to Seattle from £413

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 to Seattle departing on 25/4. 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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Icelandair Logo
12:15 - 17:00LHR-SEA
12h 45m1 stop
Icelandair Logo
14:35 - 19:30SEA-LHR
20h 55m1 stop
£477Icelandair
Find Deal
Wed, 10 Dec - Mon, 5 Jan
American Airlines Logo
11:20 - 13:17LGW-SEA
33h 57m2 stops
American Airlines Logo
06:00 - 09:00SEA-LGW
19h 00m2 stops
£479American Airlines
Find Deal
Thu, 8 Jan - Thu, 15 Jan
Icelandair Logo
15:40 - 17:50LGW-SEA
34h 10m1 stop
Icelandair Logo
19:00 - 14:40SEA-LGW
11h 40m1 stop
£480Icelandair
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Fri, 1 May - Thu, 14 May
British Airways Logo
09:50 - 16:59LHR-SEA
15h 09m1 stop
British Airways Logo
13:35 - 06:50SEA-LHR
9h 15mdirect
£480British Airways
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Sat, 16 May - Thu, 21 May
Iberia Logo
10:45 - 23:51LHR-SEA
45h 06m2 stops
Iberia Logo
10:50 - 06:50SEA-LHR
36h 00m1 stop
£481Iberia
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Sun, 1 Feb - Sun, 8 Feb
British Airways Logo
22:00 - 16:59LHR-SEA
26h 59m1 stop
British Airways Logo
20:20 - 13:45SEA-LHR
9h 25mdirect
£482British Airways
Find Deal
Sun, 19 Apr - Sun, 26 Apr
Icelandair Logo
11:55 - 18:00LGW-SEA
13h 05m1 stop
Icelandair Logo
19:00 - 14:40SEA-LGW
11h 40m1 stop
£483Icelandair
Find Deal
Mon, 16 Mar - Sat, 4 Apr
Finnair Logo
08:20 - 23:09LHR-SEA
22h 49m1 stop
Finnair Logo
15:00 - 22:10SEA-LHR
23h 10m2 stops
£486Finnair
Find Deal
Thu, 12 Feb - Mon, 23 Feb
Virgin Atlantic Logo
17:50 - 11:50LCY-SEA
26h 00m1 stop
Virgin Atlantic Logo
15:10 - 17:20SEA-LCY
18h 10m1 stop
£488Virgin Atlantic
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Mon, 12 Jan - Mon, 26 Jan
Virgin Atlantic Logo
17:50 - 11:40LCY-SEA
25h 50m1 stop
Virgin Atlantic Logo
15:05 - 16:35SEA-LCY
17h 30m1 stop
£490Virgin Atlantic
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Mon, 9 Feb - Sun, 1 Mar

Icelandair flights from London to Seattle

Our best Icelandair deals on London to Seattle flight tickets
Icelandair
10 Dec
LHR12:15London Heathrow
12h 45m
1 stop
SEA17:00Seattle/Tacoma Intl
5 Jan
SEA14:35Seattle/Tacoma Intl
20h 55m
1 stop
LHR19:30London Heathrow
Icelandair
16 Mar
LGW11:55London Gatwick
13h 05m
1 stop
SEA18:00Seattle/Tacoma Intl
4 Apr
SEA19:00Seattle/Tacoma Intl
11h 40m
1 stop
LGW14:40London Gatwick
Icelandair
10 Apr
LGW15:40London Gatwick
13h 05m
1 stop
SEA20:45Seattle/Tacoma Intl
20 Apr
SEA15:45Seattle/Tacoma Intl
14h 55m
1 stop
LGW14:40London Gatwick

Air France flights from London to Seattle

Our best Air France deals on London to Seattle flight tickets
Air France
24 Dec
LHR12:20London Heathrow
10h 38m
SEA14:58Seattle/Tacoma Intl
10 Jan
SEA18:25Seattle/Tacoma Intl
9h 30m
LHR11:55London Heathrow
Air France
8 Feb
LHR06:20London Heathrow
15h 00m
1 stop
SEA13:20Seattle/Tacoma Intl
1 Mar
SEA16:45Seattle/Tacoma Intl
9h 45m
LHR10:30London Heathrow
Air France
6 Dec
LHR12:20London Heathrow
10h 38m
SEA14:58Seattle/Tacoma Intl
26 Dec
SEA16:48Seattle/Tacoma Intl
9h 42m
LHR10:30London Heathrow

momondo Fare Finder

 
Customise your flight search to find flights from London 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 27 November 2025.
Use the filters below to find and compare flights from London to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 10/12

12:15-17:00

1 stop12h 45m

Seattle/Tacoma Intl

Mon 5/1

14:35-19:30

1 stop20h 55m

£477

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Thu 8/1

11:20-13:17

2 stops33h 57m

Seattle/Tacoma Intl

Thu 15/1

06:00-09:00

2 stops19h 00m

£479

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Fri 1/5

15:40-17:50

1 stop34h 10m

Seattle/Tacoma Intl

Thu 14/5

19:00-14:40

1 stop11h 40m

£480

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 16/5

09:50-16:59

1 stop15h 09m

Seattle/Tacoma Intl

Thu 21/5

13:35-06:50

Nonstop9h 15m

£480

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 1/2

10:45-23:51

2 stops45h 06m

Seattle/Tacoma Intl

Sun 8/2

10:50-06:50

1 stop36h 00m

£481

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 19/4

22:00-16:59

1 stop26h 59m

Seattle/Tacoma Intl

Sun 26/4

20:20-13:45

Nonstop9h 25m

£482

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Mon 16/3

11:55-18:00

1 stop13h 05m

Seattle/Tacoma Intl

Sat 4/4

19:00-14:40

1 stop11h 40m

£483

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 12/2

08:20-23:09

1 stop22h 49m

Seattle/Tacoma Intl

Mon 23/2

15:00-22:10

2 stops23h 10m

£486

LondonSeattle

LCY - SEA

LCYSEA

London City

Mon 12/1

17:50-11:50

1 stop26h 00m

Seattle/Tacoma Intl

Mon 26/1

15:10-17:20

1 stop18h 10m

£488

LondonSeattle

LCY - SEA

LCYSEA

London City

Mon 9/2

17:50-11:40

1 stop25h 50m

Seattle/Tacoma Intl

Sun 1/3

15:05-16:35

1 stop17h 30m

£490

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 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 is in February. Flight prices, which tend to average around £506, are often lower during this time because this is during the off-season. The month of January is another great option to travel to Seattle, with average flight prices from London averaging around £507.

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. The lowest ticket price found for a Wednesday departure recently was £600. 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 £690.

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 to Seattle in the evening for as low as £535. 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 £635.

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

Fly from London Heathrow to Seattle/Tacoma Intl for the best London - 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 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 for as low as £536 on momondo.

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

There are 4 cabin classes available to choose from on London 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 to Seattle flights?

You could potentially save up to 19% on your flight if you consider stops on a London to Seattle flight.

How have London to Seattle flight prices changed over time?

As of November 2025, prices for London to Seattle flights are approximately 14% more expensive when compared to flights at the same time last year.

When to book flights from London to Seattle

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

Cheap London to Seattle (LON to SEA) flight deals and tips

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

Best price found

£450

Fastest flight time

9h 45m

Direct flights

Every day

Airports in Seattle

1 airport
The best one-way flight to Seattle from London in the past 72 hours is £450. The best return flight deal from London to Seattle found on momondo in the last 72 hours is £531.
The fastest flight from London to Seattle takes 9h 45m
Direct flights go from London to Seattle every day.
There is 1 airport near Seattle: Seattle/Tacoma Intl (SEA)
  • How far is London to Seattle/Tacoma Intl by plane?

    A flight from London to Seattle/Tacoma Intl will travel around 4781.3 mi. By plane, this route typically takes 9h 45m.

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

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

  • How many operators does momondo search for flights from London to Seattle/Tacoma Intl Airport?

  • How old do you have to be to fly from London 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 to Seattle/Tacoma Intl Airport.

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

    The travel and health documents you'll need for your trip to Seattle/Tacoma Intl Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Seattle/Tacoma Intl Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

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

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

Best airlines flying from London to Seattle

Compare and see reviews for airlines that fly from London to Seattle with momondo
Airline
Rating
Free Cancellation
Price
IcelandairPriceFrom £330Free CancellationRating
7.0
582 reviews
Search Icelandair flights
Air FrancePriceFrom £391Free CancellationRating
7.4
1,498 reviews
Search Air France flights
FinnairPriceFrom £403Free CancellationRating
7.6
1,334 reviews
Search Finnair flights
LufthansaPriceFrom £406Free CancellationRating
6.8
7,594 reviews
Search Lufthansa flights
KLMPriceFrom £407Free CancellationRating
7.7
1,423 reviews
Search KLM flights
United AirlinesPriceFrom £412Free CancellationRating
7.4
9,050 reviews
Search United Airlines flights
British AirwaysPriceFrom £447Free CancellationRating
6.7
7,539 reviews
Search British Airways flights
Virgin AtlanticPriceFrom £449Free CancellationRating
7.5
675 reviews
Search Virgin Atlantic flights
DeltaPriceFrom £452Free CancellationRating
7.9
8,004 reviews
Search Delta flights
Aer LingusPriceFrom £464Free CancellationRating
7.2
1,382 reviews
Search Aer Lingus flights
  • Delta Flights From London to Seattle

    Delta flight deals from London to Seattle start from £452 round-trip. Over the 8 Delta flights for this route in a normal week, average airfare is usually £589 round-trip - but some users have found much cheaper deals with momondo.

  • KLM Flights From London to Seattle

    KLM (7.7/10 from 1,423 reviews) operates around 8 flights from London to Seattle in any given week. The average KLM airfare for this route is around £579, with deals from around £407 rare but found on momondo. Referenced prices are for round-trip London 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?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from London to Seattle. momondo saves you time and could save you money on your trip.

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

Yes. momondo allows you to filter the results for London to Seattle flights to just show those with flexible booking policies.

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 can track prices for London to Seattle 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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1 adult
Sat 27/12
Sat 3/1

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