Cheap flights from London to Seattle from £346

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 10/3. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Cheap return flights

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Virgin Atlantic Logo
12:20 - 14:45
LHR
-
SEA
10h 25mdirect
Virgin Atlantic Logo
11:35 - 10:40
SEA
-
LHR
15h 05m
1 stop
£349Virgin Atlantic
Mon, 16 Feb - Mon, 2 Mar
Icelandair Logo
21:25 - 17:55
LHR
-
SEA
28h 30m
1 stop
Icelandair Logo
15:40 - 11:55
SEA
-
LHR
12h 15m
1 stop
£353Icelandair
Fri, 1 May - Sun, 10 May
Icelandair Logo
21:25 - 20:40
LHR
-
SEA
31h 15m
1 stop
Icelandair Logo
19:00 - 20:20
SEA
-
LHR
17h 20m
1 stop
£354Icelandair
Mon, 4 May - Fri, 8 May
Icelandair Logo
21:25 - 20:40
LHR
-
SEA
31h 15m
1 stop
Icelandair Logo
15:40 - 11:55
SEA
-
LHR
12h 15m
1 stop
£358Icelandair
Sun, 12 Apr - Sat, 18 Apr
Icelandair Logo
13:05 - 17:55
LHR
-
SEA
12h 50m
1 stop
Icelandair Logo
15:40 - 20:20
SEA
-
LHR
20h 40m
1 stop
£360Icelandair
Thu, 9 Apr - Mon, 4 May
Delta Logo
10:45 - 22:05
LHR
-
SEA
19h 20m
1 stop
Delta Logo
21:50 - 15:35
SEA
-
LHR
9h 45mdirect
£360Delta
Tue, 9 Jun - Tue, 8 Sep
KLM Logo
06:30 - 11:40
LHR
-
SEA
13h 10m
1 stop
KLM Logo
08:00 - 07:05
SEA
-
LHR
15h 05m
1 stop
£361KLM
Mon, 16 Feb - Mon, 2 Mar
Virgin Atlantic Logo
20:25 - 12:35
LHR
-
SEA
23h 10m
1 stop
Virgin Atlantic Logo
13:32 - 10:00
SEA
-
LHR
13h 28m
1 stop
£364Virgin Atlantic
Mon, 16 Mar - Mon, 23 Mar
SWISS Logo
19:20 - 21:01
LCY
-
SEA
33h 41m
2 stops
SWISS Logo
12:32 - 17:05
SEA
-
LCY
20h 33m
2 stops
£426SWISS
Sun, 22 Feb - Wed, 25 Feb
KLM Logo
10:00 - 16:30
LCY
-
SEA
14h 30m
1 stop
KLM Logo
09:00 - 08:50
SEA
-
LCY
15h 50m
2 stops
£429KLM
Tue, 14 Apr - Tue, 21 Apr

Turkish Airlines flights from London to Seattle

Our best Turkish Airlines deals on London to Seattle flight tickets
Turkish Airlines
27 Apr
STN10:50London Stansted
38h 25m
1 stop
SEA17:15Seattle/Tacoma Intl
4 May
SEA19:10Seattle/Tacoma Intl
19h 00m
1 stop
STN22:10London Stansted
£673
Turkish Airlines
1 Feb
LGW17:05London Gatwick
32h 00m
1 stop
SEA17:05Seattle/Tacoma Intl
7 Feb
SEA19:00Seattle/Tacoma Intl
19h 35m
1 stop
LGW22:35London Gatwick
£702

Icelandair flights from London to Seattle

Our best Icelandair deals on London to Seattle flight tickets
Icelandair
1 May
LHR21:25London Heathrow
28h 30m
1 stop
SEA17:55Seattle/Tacoma Intl
10 May
SEA15:40Seattle/Tacoma Intl
12h 15m
1 stop
LHR11:55London Heathrow
£353
Icelandair
4 May
LHR21:25London Heathrow
28h 30m
1 stop
SEA17:55Seattle/Tacoma Intl
12 May
SEA15:40Seattle/Tacoma Intl
12h 15m
1 stop
LHR11:55London Heathrow
£354
Icelandair
12 Apr
LHR21:25London Heathrow
31h 15m
1 stop
SEA20:40Seattle/Tacoma Intl
18 Apr
SEA15:40Seattle/Tacoma Intl
12h 15m
1 stop
LHR11:55London Heathrow
£358

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 31 January 2026.
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

Mon 16/2

12:20-14:45

Nonstop10h 25m

Seattle/Tacoma Intl

Mon 2/3

11:35-10:40

1 stop15h 05m

£349

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 1/5

21:25-17:55

1 stop28h 30m

Seattle/Tacoma Intl

Sun 10/5

15:40-11:55

1 stop12h 15m

£353

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 4/5

21:25-20:40

1 stop31h 15m

Seattle/Tacoma Intl

Fri 8/5

19:00-20:20

1 stop17h 20m

£354

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 12/4

21:25-20:40

1 stop31h 15m

Seattle/Tacoma Intl

Sat 18/4

15:40-11:55

1 stop12h 15m

£358

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 9/4

13:05-17:55

1 stop12h 50m

Seattle/Tacoma Intl

Mon 4/5

15:40-20:20

1 stop20h 40m

£360

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 9/6

10:45-22:05

1 stop19h 20m

Seattle/Tacoma Intl

Tue 8/9

21:50-15:35

Nonstop9h 45m

£360

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 16/2

06:30-11:40

1 stop13h 10m

Seattle/Tacoma Intl

Mon 2/3

08:00-07:05

1 stop15h 05m

£361

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 16/3

20:25-12:35

1 stop23h 10m

Seattle/Tacoma Intl

Mon 23/3

13:32-10:00

1 stop13h 28m

£364

LondonSeattle

LCY - SEA

LCYSEA

London City

Sun 22/2

19:20-21:01

2 stops33h 41m

Seattle/Tacoma Intl

Wed 25/2

12:32-17:05

2 stops20h 33m

£426

LondonSeattle

LCY - SEA

LCYSEA

London City

Tue 14/4

10:00-16:30

1 stop14h 30m

Seattle/Tacoma Intl

Tue 21/4

09:00-08:50

2 stops15h 50m

£429

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 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 February. Flight prices, which tend to average around £448, 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 £469.

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 £569. 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 £638.

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 morning. momondo users have found flights departing from London to Seattle in the morning for as low as £597. 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 £608.

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 £547 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 £512 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 1% 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 January 2026, prices for London to Seattle flights are approximately 7% cheaper 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 £445.
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
LufthansaPriceFrom £328Free CancellationRating
6.8
7,758 reviews
Search Lufthansa flights
IcelandairPriceFrom £335Free CancellationRating
7.1
606 reviews
Search Icelandair flights
IberiaPriceFrom £397Free CancellationRating
7.0
3,100 reviews
Search Iberia flights
Aer LingusPriceFrom £408Free CancellationRating
7.2
1,444 reviews
Search Aer Lingus flights
Air CanadaPriceFrom £411Free CancellationRating
7.1
10,668 reviews
Search Air Canada flights
United AirlinesPriceFrom £420Free CancellationRating
7.4
9,219 reviews
Search United Airlines flights
Virgin AtlanticPriceFrom £421Free CancellationRating
7.5
678 reviews
Search Virgin Atlantic flights
FinnairPriceFrom £427Free CancellationRating
7.6
1,356 reviews
Search Finnair flights
DeltaPriceFrom £431Free CancellationRating
7.9
8,130 reviews
Search Delta flights
KLMPriceFrom £431Free CancellationRating
7.7
1,444 reviews
Search KLM flights
  • Delta Flights From London to Seattle

    Delta flight deals from London to Seattle start from £431 round-trip. Over the 3 Delta flights for this route in a normal week, average airfare is usually £600 round-trip - but some users have found much cheaper deals with momondo.

  • KLM Flights From London to Seattle

    KLM (7.7/10 from 1,444 reviews) operates around 3 flights from London to Seattle in any given week. The average KLM airfare for this route is around £562, with deals from around £431 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
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.

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1 adult
Mon 2/3
Mon 9/3

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