Cheap flights from London to Seattle from £393

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 25/3. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

Discover deals from 900+ travel sites with momondo.

Voted winner of Europe's Best Travel App 2023

Save money when you book flights with momondo

Big names, great deals

Big names, great deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Stopover? Instantly customise your results.

Trusted and free

Trusted and free

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

Price Alerts

Price Alerts

Not ready to book? to track prices.

Find the cheapest flights from London to Seattle

Cheap return flights

Enter your travel dates to find the best prices.
British Airways Logo
14:55 - 16:55
LHR
-
SEA
10h 00mdirect
British Airways Logo
18:50 - 12:20
SEA
-
LHR
9h 30mdirect
£443British Airways
Fri, 16 Jan - Mon, 26 Jan
Icelandair Logo
15:40 - 20:40
LGW
-
SEA
13h 00m1 stop
Icelandair Logo
15:40 - 14:40
SEA
-
LGW
15h 00m1 stop
£444Icelandair
Sat, 25 Apr - Sat, 2 May
Iberia Logo
14:10 - 22:20
LHR
-
SEA
16h 10m1 stop
Iberia Logo
08:35 - 06:50
SEA
-
LHR
14h 15m1 stop
£444Iberia
Sun, 18 Jan - Wed, 28 Jan
British Airways Logo
09:25 - 11:30
LHR
-
SEA
10h 05mdirect
British Airways Logo
13:35 - 07:10
SEA
-
LHR
9h 35mdirect
£445British Airways
Sat, 31 Jan - Sat, 7 Feb
Virgin Atlantic Logo
08:25 - 22:05
LCY
-
SEA
21h 40m2 stops
Virgin Atlantic Logo
15:35 - 16:40
SEA
-
LCY
17h 05m2 stops
£446Virgin Atlantic
Tue, 14 Apr - Tue, 21 Apr
Finnair Logo
09:45 - 23:05
LHR
-
SEA
21h 20m2 stops
Finnair Logo
22:36 - 06:55
SEA
-
LHR
24h 19m1 stop
£447Finnair
Thu, 9 Apr - Mon, 13 Apr
Icelandair Logo
15:40 - 20:40
LGW
-
SEA
13h 00m1 stop
Icelandair Logo
19:00 - 14:40
SEA
-
LGW
11h 40m1 stop
£447Icelandair
Mon, 13 Apr - Mon, 20 Apr
British Airways Logo
09:50 - 16:59
LHR
-
SEA
15h 09m1 stop
British Airways Logo
13:35 - 06:50
SEA
-
LHR
9h 15mdirect
£448British Airways
Sat, 30 May - Sat, 13 Jun
Virgin Atlantic Logo
17:25 - 19:45
LHR
-
SEA
10h 20mdirect
Virgin Atlantic Logo
15:35 - 09:00
SEA
-
LHR
9h 25mdirect
£449Virgin Atlantic
Sat, 25 Apr - Sat, 2 May
Finnair Logo
09:15 - 21:46
LHR
-
SEA
20h 31m1 stop
Finnair Logo
23:33 - 07:50
SEA
-
LHR
24h 17m1 stop
£450Finnair
Thu, 9 Apr - Mon, 13 Apr

Icelandair flights from London to Seattle

Our best Icelandair deals on London to Seattle flight tickets
Icelandair
25 Apr
LGW15:40London Gatwick
13h 00m
1 stop
SEA20:40Seattle/Tacoma Intl
2 May
SEA15:40Seattle/Tacoma Intl
15h 00m
1 stop
LGW14:40London Gatwick
Icelandair
13 Apr
LGW15:40London Gatwick
13h 00m
1 stop
SEA20:40Seattle/Tacoma Intl
20 Apr
SEA19:00Seattle/Tacoma Intl
11h 40m
1 stop
LGW14:40London Gatwick
Icelandair
10 Apr
LGW15:40London Gatwick
13h 00m
1 stop
SEA20:40Seattle/Tacoma Intl
20 Apr
SEA15:40Seattle/Tacoma Intl
15h 00m
1 stop
LGW14:40London Gatwick

Iberia flights from London to Seattle

Our best Iberia deals on London to Seattle flight tickets
Iberia
18 Jan
LHR14:10London Heathrow
16h 10m
1 stop
SEA22:20Seattle/Tacoma Intl
28 Jan
SEA08:35Seattle/Tacoma Intl
14h 15m
1 stop
LHR06:50London Heathrow
Iberia
13 Jan
LHR08:20London Heathrow
21h 27m
1 stop
SEA21:47Seattle/Tacoma Intl
20 Jan
SEA08:04Seattle/Tacoma Intl
22h 51m
2 stops
LHR14:55London Heathrow
Iberia
15 Jan
LHR14:10London Heathrow
16h 10m
1 stop
SEA22:20Seattle/Tacoma Intl
22 Jan
SEA08:04Seattle/Tacoma Intl
25h 11m
2 stops
LHR17:15London 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 18 December 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

Fri 16/1

14:55-16:55

Nonstop10h 00m

Seattle/Tacoma Intl

Mon 26/1

18:50-12:20

Nonstop9h 30m

£443

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Sat 25/4

15:40-20:40

1 stop13h 00m

Seattle/Tacoma Intl

Sat 2/5

15:40-14:40

1 stop15h 00m

£444

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 18/1

14:10-22:20

1 stop16h 10m

Seattle/Tacoma Intl

Wed 28/1

08:35-06:50

1 stop14h 15m

£444

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 31/1

09:25-11:30

Nonstop10h 05m

Seattle/Tacoma Intl

Sat 7/2

13:35-07:10

Nonstop9h 35m

£445

LondonSeattle

LCY - SEA

LCYSEA

London City

Tue 14/4

08:25-22:05

2 stops21h 40m

Seattle/Tacoma Intl

Tue 21/4

15:35-16:40

2 stops17h 05m

£446

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 9/4

09:45-23:05

2 stops21h 20m

Seattle/Tacoma Intl

Mon 13/4

22:36-06:55

1 stop24h 19m

£447

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Mon 13/4

15:40-20:40

1 stop13h 00m

Seattle/Tacoma Intl

Mon 20/4

19:00-14:40

1 stop11h 40m

£447

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 30/5

09:50-16:59

1 stop15h 09m

Seattle/Tacoma Intl

Sat 13/6

13:35-06:50

Nonstop9h 15m

£448

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 25/4

17:25-19:45

Nonstop10h 20m

Seattle/Tacoma Intl

Sat 2/5

15:35-09:00

Nonstop9h 25m

£449

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 9/4

09:15-21:46

1 stop20h 31m

Seattle/Tacoma Intl

Mon 13/4

23:33-07:50

1 stop24h 17m

£450

Flights are sorted by cheapest return flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

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

What is the cheapest month to fly to Seattle?

The cheapest month to fly to Seattle from London is in January. Flight prices, which tend to average around £481, are often lower during this time because this is during the off-season. The month of February is another great option to travel to Seattle, with average flight prices from London averaging around £488.

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 £589. 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 £661.

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 £528. 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 £621.

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 £571 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 £523 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 7% 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 December 2025, prices for London to Seattle flights are approximately 15% 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

£538

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 £538. The best return flight deal from London to Seattle found on momondo in the last 72 hours is £507.
The fastest flight from London to Seattle takes 9h 45m
Direct flights go from London to Seattle every day.
There is 1 airport in Seattle. From London there are direct flights to 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 £326Free CancellationRating
7.0
591 reviews
Search Icelandair flights
Air FrancePriceFrom £386Free CancellationRating
7.4
1,507 reviews
Search Air France flights
LufthansaPriceFrom £397Free CancellationRating
6.8
7,635 reviews
Search Lufthansa flights
KLMPriceFrom £399Free CancellationRating
7.7
1,428 reviews
Search KLM flights
FinnairPriceFrom £399Free CancellationRating
7.6
1,338 reviews
Search Finnair flights
United AirlinesPriceFrom £407Free CancellationRating
7.4
9,091 reviews
Search United Airlines flights
Aer LingusPriceFrom £419Free CancellationRating
7.2
1,395 reviews
Search Aer Lingus flights
British AirwaysPriceFrom £439Free CancellationRating
6.7
7,585 reviews
Search British Airways flights
Virgin AtlanticPriceFrom £443Free CancellationRating
7.5
675 reviews
Search Virgin Atlantic flights
DeltaPriceFrom £446Free CancellationRating
7.9
8,005 reviews
Search Delta flights
  • Delta Flights From London to Seattle

    Delta flight deals from London to Seattle start from £446 round-trip. Over the 10 Delta flights for this route in a normal week, average airfare is usually £585 round-trip - but some users have found much cheaper deals with momondo.

  • KLM Flights From London to Seattle

    KLM (7.7/10 from 1,428 reviews) operates around 10 flights from London to Seattle in any given week. The average KLM airfare for this route is around £569, with deals from around £399 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
Tukwila

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.

An easier way to manage your Seattle trip

We make it super easy to schedule, organise 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.
1 adult
Sat 17/1
Sat 24/1

Find better results for your trip to the United States