Cheap flights from London to Seattle from £419

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 19/2. 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.
Delta Logo
15:05 - 17:10LHR-SEA
10h 05mdirect
Delta Logo
16:45 - 10:30SEA-LHR
9h 45mdirect
£470Delta
Find Deal
Sat, 7 Feb - Wed, 4 Mar
Icelandair Logo
20:35 - 17:00LHR-SEA
28h 25m1 stop
Icelandair Logo
14:35 - 19:30SEA-LHR
20h 55m1 stop
£472Icelandair
Find Deal
Mon, 17 Nov - Sun, 30 Nov
British Airways Logo
09:25 - 11:30LHR-SEA
10h 05mdirect
British Airways Logo
19:50 - 12:20SEA-LHR
9h 30mdirect
£475British Airways
Find Deal
Sat, 28 Feb - Sun, 8 Mar
British Airways Logo
09:25 - 11:30LHR-SEA
10h 05mdirect
British Airways Logo
13:25 - 07:00SEA-LHR
9h 35mdirect
£476British Airways
Find Deal
Tue, 24 Feb - Tue, 3 Mar
Virgin Atlantic Logo
08:40 - 20:46LCY-SEA
20h 06m2 stops
Virgin Atlantic Logo
15:10 - 17:20SEA-LCY
18h 10m1 stop
£477Virgin Atlantic
Find Deal
Sat, 10 Jan - Sun, 25 Jan
Virgin Atlantic Logo
08:40 - 20:46LCY-SEA
20h 06m2 stops
Virgin Atlantic Logo
06:05 - 08:10SEA-LCY
18h 05m2 stops
£478Virgin Atlantic
Find Deal
Sat, 24 Jan - Wed, 28 Jan
Finnair Logo
10:15 - 23:08LHR-SEA
19h 53m2 stops
Finnair Logo
13:55 - 12:00SEA-LHR
15h 05m1 stop
£497Finnair
Find Deal
Tue, 10 Mar - Tue, 17 Mar
Finnair Logo
15:35 - 10:23LHR-SEA
26h 48m2 stops
Finnair Logo
11:31 - 22:10SEA-LHR
27h 39m2 stops
£498Finnair
Find Deal
Wed, 18 Feb - Wed, 11 Mar
KLM Logo
08:40 - 15:50LCY-SEA
15h 10m1 stop
KLM Logo
17:35 - 16:40SEA-LCY
15h 05m1 stop
£616KLM
Find Deal
Tue, 14 Apr - Thu, 14 May
KLM Logo
10:00 - 15:50LCY-SEA
13h 50m1 stop
KLM Logo
09:30 - 09:30SEA-LCY
16h 00m2 stops
£650KLM
Find Deal
Thu, 2 Apr - Fri, 10 Apr

Icelandair flights from London to Seattle

Our best Icelandair deals on London to Seattle flight tickets
Icelandair
17 Nov
LHR20:35London Heathrow
28h 25m
1 stop
SEA17:00Seattle/Tacoma Intl
30 Nov
SEA14:35Seattle/Tacoma Intl
20h 55m
1 stop
LHR19:30London Heathrow
Icelandair
3 Dec
LHR12:15London Heathrow
12h 45m
1 stop
SEA17:00Seattle/Tacoma Intl
6 Dec
SEA14:35Seattle/Tacoma Intl
12h 15m
1 stop
LHR10:50London Heathrow
Icelandair
25 Nov
LGW11:55London Gatwick
13h 05m
1 stop
SEA17:00Seattle/Tacoma Intl
3 Dec
SEA14:35Seattle/Tacoma Intl
12h 20m
1 stop
LGW10:55London Gatwick

British Airways flights from London to Seattle

Our best British Airways deals on London to Seattle flight tickets
British Airways
28 Feb
LHR09:25London Heathrow
10h 05m
SEA11:30Seattle/Tacoma Intl
8 Mar
SEA19:50Seattle/Tacoma Intl
9h 30m
LHR12:20London Heathrow
British Airways
24 Feb
LHR09:25London Heathrow
10h 05m
SEA11:30Seattle/Tacoma Intl
3 Mar
SEA13:25Seattle/Tacoma Intl
9h 35m
LHR07:00London Heathrow
British Airways
10 Mar
LHR14:55London Heathrow
10h 00m
SEA17:55Seattle/Tacoma Intl
17 Mar
SEA14:25Seattle/Tacoma Intl
9h 35m
LHR07:00London 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 7 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

Sat 7/2

15:05-17:10

Nonstop10h 05m

Seattle/Tacoma Intl

Wed 4/3

16:45-10:30

Nonstop9h 45m

£470

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 17/11

20:35-17:00

1 stop28h 25m

Seattle/Tacoma Intl

Sun 30/11

14:35-19:30

1 stop20h 55m

£472

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 28/2

09:25-11:30

Nonstop10h 05m

Seattle/Tacoma Intl

Sun 8/3

19:50-12:20

Nonstop9h 30m

£475

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 24/2

09:25-11:30

Nonstop10h 05m

Seattle/Tacoma Intl

Tue 3/3

13:25-07:00

Nonstop9h 35m

£476

LondonSeattle

LCY - SEA

LCYSEA

London City

Sat 10/1

08:40-20:46

2 stops20h 06m

Seattle/Tacoma Intl

Sun 25/1

15:10-17:20

1 stop18h 10m

£477

LondonSeattle

LCY - SEA

LCYSEA

London City

Sat 24/1

08:40-20:46

2 stops20h 06m

Seattle/Tacoma Intl

Wed 28/1

06:05-08:10

2 stops18h 05m

£478

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/3

10:15-23:08

2 stops19h 53m

Seattle/Tacoma Intl

Tue 17/3

13:55-12:00

1 stop15h 05m

£497

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 18/2

15:35-10:23

2 stops26h 48m

Seattle/Tacoma Intl

Wed 11/3

11:31-22:10

2 stops27h 39m

£498

LondonSeattle

LCY - SEA

LCYSEA

London City

Tue 14/4

08:40-15:50

1 stop15h 10m

Seattle/Tacoma Intl

Thu 14/5

17:35-16:40

1 stop15h 05m

£616

LondonSeattle

LCY - SEA

LCYSEA

London City

Thu 2/4

10:00-15:50

1 stop13h 50m

Seattle/Tacoma Intl

Fri 10/4

09:30-09:30

2 stops16h 00m

£650

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 £484, 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 £506.

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 £605. 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 £699.

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 £539. 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 £645.

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 £592 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 £554 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 20% 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 16% 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

£491

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 £491. The best return flight deal from London to Seattle found on momondo in the last 72 hours is £562.
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 £352Free CancellationRating
7.1
572 reviews
Search Icelandair flights
Air FrancePriceFrom £395Free CancellationRating
7.4
1,484 reviews
Search Air France flights
FinnairPriceFrom £408Free CancellationRating
7.6
1,335 reviews
Search Finnair flights
LufthansaPriceFrom £409Free CancellationRating
6.8
7,558 reviews
Search Lufthansa flights
KLMPriceFrom £413Free CancellationRating
7.7
1,408 reviews
Search KLM flights
United AirlinesPriceFrom £416Free CancellationRating
7.4
9,007 reviews
Search United Airlines flights
British AirwaysPriceFrom £451Free CancellationRating
6.7
7,500 reviews
Search British Airways flights
Virgin AtlanticPriceFrom £453Free CancellationRating
7.5
672 reviews
Search Virgin Atlantic flights
DeltaPriceFrom £456Free CancellationRating
7.9
8,000 reviews
Search Delta flights
Aer LingusPriceFrom £468Free CancellationRating
7.2
1,365 reviews
Search Aer Lingus flights
  • Delta Flights From London to Seattle

    Delta flight deals from London to Seattle start from £456 round-trip. Over the 10 Delta flights for this route in a normal week, average airfare is usually £611 round-trip - but some users have found much cheaper deals with momondo.

  • KLM Flights From London to Seattle

    KLM (7.7/10 from 1,405 reviews) operates around 10 flights from London to Seattle in any given week. The average KLM airfare for this route is around £584, with deals from around £413 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.

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
Sun 7/12
Sun 14/12

Find better results for your trip to the United States