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Cheap flights from London to Seattle from £249

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 9/6. 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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0 bags

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Cheap return flights

These are some of the best return flight deals from London to Seattle that have been recently found on momondo from popular airlines, departing in the coming months.
Icelandair Logo
15:40 - 20:40LGW-SEA
13h 00m1 stop
Icelandair Logo
15:45 - 14:40SEA-LGW
14h 55m1 stop
£394Icelandair
Find Deal
Sat, 10 May - Fri, 16 May
Icelandair Logo
15:40 - 11:25LGW-SEA
27h 45m1 stop
Icelandair Logo
15:45 - 14:40SEA-LGW
14h 55m1 stop
£405Icelandair
Find Deal
Sun, 7 Sep - Fri, 19 Sep
British Airways Logo
07:40 - 17:50LHR-SEA
18h 10m1 stop
British Airways Logo
20:20 - 13:40SEA-LHR
9h 20mdirect
£462British Airways
Find Deal
Wed, 17 Sep - Thu, 25 Sep
British Airways Logo
06:20 - 16:59LHR-SEA
18h 39m1 stop
British Airways Logo
13:30 - 06:50SEA-LHR
9h 20mdirect
£477British Airways
Find Deal
Tue, 13 May - Tue, 20 May
Virgin Atlantic Logo
06:15 - 11:15LHR-SEA
13h 00m1 stop
Virgin Atlantic Logo
20:20 - 14:15SEA-LHR
9h 55mdirect
£489Virgin Atlantic
Find Deal
Tue, 13 May - Fri, 23 May
Virgin Atlantic Logo
17:25 - 19:40LHR-SEA
10h 15mdirect
Virgin Atlantic Logo
17:35 - 11:20SEA-LHR
9h 45mdirect
£494Virgin Atlantic
Find Deal
Mon, 12 May - Fri, 23 May
KLM Logo
09:55 - 15:57LHR-SEA
14h 02m1 stop
KLM Logo
17:35 - 11:20SEA-LHR
9h 45mdirect
£497KLM
Find Deal
Mon, 12 May - Fri, 23 May
Air France Logo
17:25 - 19:50LHR-SEA
10h 25mdirect
Air France Logo
20:25 - 14:15SEA-LHR
9h 50mdirect
£500Air France
Find Deal
Wed, 3 Sep - Wed, 17 Sep
Air France Logo
17:25 - 19:40LHR-SEA
10h 15mdirect
Air France Logo
20:20 - 14:15SEA-LHR
9h 55mdirect
£505Air France
Find Deal
Mon, 12 May - Fri, 23 May
KLM Logo
18:30 - 20:55LHR-SEA
10h 25mdirect
KLM Logo
20:25 - 14:15SEA-LHR
9h 50mdirect
£538KLM
Find Deal
Sun, 7 Sep - Fri, 19 Sep

Finnair flights from London to Seattle

Our best Finnair deals on London to Seattle flight tickets
Finnair
3 Sept
LHR11:15London Heathrow
16h 32m
1 stop
SEA19:47Seattle/Tacoma Intl
17 Sept
SEA23:59Seattle/Tacoma Intl
25h 46m
2 stops
LHR09:45London Heathrow
Finnair
3 Sept
LHR16:30London Heathrow
9h 50m
SEA18:20Seattle/Tacoma Intl
17 Sept
SEA23:59Seattle/Tacoma Intl
25h 46m
2 stops
LHR09:45London Heathrow
Finnair
13 May
LHR10:05London Heathrow
22h 40m
2 stops
SEA00:45Seattle/Tacoma Intl
18 May
SEA23:59Seattle/Tacoma Intl
22h 16m
2 stops
LHR06:15London Heathrow

British Airways flights from London to Seattle

Our best British Airways deals on London to Seattle flight tickets
British Airways
17 Sept
LHR07:40London Heathrow
18h 10m
1 stop
SEA17:50Seattle/Tacoma Intl
25 Sept
SEA20:20Seattle/Tacoma Intl
9h 20m
LHR13:40London Heathrow
British Airways
13 May
LHR06:20London Heathrow
18h 39m
1 stop
SEA16:59Seattle/Tacoma Intl
20 May
SEA13:30Seattle/Tacoma Intl
9h 20m
LHR06:50London Heathrow
British Airways
12 May
LHR06:20London Heathrow
18h 39m
1 stop
SEA16:59Seattle/Tacoma Intl
19 May
SEA13:30Seattle/Tacoma Intl
9h 20m
LHR06:50London Heathrow

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 £471, are often lower during this time because this is during the off-season. The month of March is another great option to travel to Seattle, with average flight prices from London averaging around £489.

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

According to our data, Tuesday is the cheapest day to fly to Seattle from London. The lowest ticket price found for a Tuesday departure recently was £615. 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 £741.

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 £526. 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 £669.

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 24 weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around £585 when searching 24 weeks out.However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from London for as low as £524 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.

How have London to Seattle flight prices changed over time?

As of April 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

£249

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 £249. The best return flight deal from London to Seattle found on momondo in the last 72 hours is £394.
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
Aer LingusPriceFrom £8Free CancellationRating
7.0
1,076 reviews
Search Aer Lingus flights
IcelandairPriceFrom £326Free CancellationRating
7.0
487 reviews
Search Icelandair flights
Air FrancePriceFrom £386Free CancellationRating
7.4
1,446 reviews
Search Air France flights
LufthansaPriceFrom £396Free CancellationRating
6.7
7,044 reviews
Search Lufthansa flights
United AirlinesPriceFrom £399Free CancellationRating
7.4
8,696 reviews
Search United Airlines flights
KLMPriceFrom £407Free CancellationRating
7.8
1,334 reviews
Search KLM flights
FinnairPriceFrom £415Free CancellationRating
7.6
1,275 reviews
Search Finnair flights
British AirwaysPriceFrom £433Free CancellationRating
6.6
6,842 reviews
Search British Airways flights
DeltaPriceFrom £445Free CancellationRating
8.0
7,934 reviews
Search Delta flights
Virgin AtlanticPriceFrom £450Free CancellationRating
7.4
642 reviews
Search Virgin Atlantic flights
  • Delta Flights From London to Seattle

    Delta flight deals from London to Seattle start from £597 round-trip. Over the 12 Delta flights for this route in a normal week, average airfare is usually £826 round-trip - but some users have found much cheaper deals with momondo.

  • KLM Flights From London to Seattle

    KLM (7.8/10 from 1,334 reviews) operates around 12 flights from London to Seattle in any given week. The average KLM airfare for this route is around £780, with deals from around £546 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
Kent
Tukwila
SeaTac
Fife
Mukilteo
Renton

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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