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Cheap flights from London to Seattle from C$ 781

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 29/1. 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 round-trip flights

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Icelandair Logo
12:15 p.m. - 6:00 p.m.LHR-SEA
12h 45m1 stop
Icelandair Logo
3:45 p.m. - 11:55 a.m.SEA-LHR
12h 10m1 stop
C$ 874Icelandair
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Thu, 19 Mar - Mon, 30 Mar
Icelandair Logo
8:35 p.m. - 6:00 p.m.LHR-SEA
28h 25m1 stop
Icelandair Logo
3:35 p.m. - 10:50 a.m.SEA-LHR
12h 15m1 stop
C$ 877Icelandair
Find Deal
Sat, 21 Mar - Thu, 26 Mar
Delta Logo
8:40 a.m. - 11:40 a.m.LHR-SEA
35h 00m1 stop
Delta Logo
7:20 a.m. - 6:50 a.m.SEA-LHR
15h 30m1 stop
C$ 892Delta
Find Deal
Sun, 8 Feb - Wed, 18 Feb
Delta Logo
6:20 a.m. - 11:25 a.m.LHR-SEA
13h 05m1 stop
Delta Logo
4:55 p.m. - 10:30 a.m.SEA-LHR
9h 35mdirect
C$ 899Delta
Find Deal
Sat, 7 Feb - Wed, 18 Feb
British Airways Logo
9:25 a.m. - 12:30 p.m.LHR-SEA
10h 05mdirect
British Airways Logo
2:35 p.m. - 7:10 a.m.SEA-LHR
9h 35mdirect
C$ 915British Airways
Find Deal
Sat, 21 Mar - Sat, 28 Mar
Multiple Airlines Logo
6:30 a.m. - 11:40 a.m.LHR-SEA
13h 10m1 stop
Multiple Airlines Logo
5:40 p.m. - 10:30 a.m.SEA-LHR
9h 50mdirect
C$ 924Multiple Airlines
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Tue, 24 Feb - Sun, 8 Mar
United Airlines Logo
4:40 p.m. - 1:20 p.m.LHR-SEA
28h 40m1 stop
United Airlines Logo
5:00 a.m. - 9:40 a.m.SEA-LHR
20h 40m1 stop
C$ 929United Airlines
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Tue, 10 Feb - Wed, 18 Feb
British Airways Logo
2:55 p.m. - 4:55 p.m.LHR-SEA
10h 00mdirect
British Airways Logo
6:50 p.m. - 12:20 p.m.SEA-LHR
9h 30mdirect
C$ 930British Airways
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Thu, 5 Feb - Wed, 18 Feb
United Airlines Logo
6:30 a.m. - 12:10 p.m.LHR-SEA
13h 40m1 stop
United Airlines Logo
7:00 a.m. - 7:55 a.m.SEA-LHR
16h 55m1 stop
C$ 931United Airlines
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Mon, 9 Feb - Wed, 18 Feb
Multiple Airlines Logo
6:30 a.m. - 11:45 a.m.LHR-SEA
13h 15m1 stop
Multiple Airlines Logo
4:48 p.m. - 10:30 a.m.SEA-LHR
9h 42mdirect
C$ 1,005Multiple Airlines
Find Deal
Wed, 12 Nov - Wed, 19 Nov

Delta flights from London to Seattle

Our best Delta deals on London to Seattle flight tickets
Delta
8 Feb
LHR8:40 a.m.London Heathrow
35h 00m
1 stop
SEA11:40 a.m.Seattle/Tacoma Intl
18 Feb
SEA7:20 a.m.Seattle/Tacoma Intl
15h 30m
1 stop
LHR6:50 a.m.London Heathrow
C$ 892
Find similar
Delta
7 Feb
LHR6:20 a.m.London Heathrow
13h 05m
1 stop
SEA11:25 a.m.Seattle/Tacoma Intl
18 Feb
SEA4:55 p.m.Seattle/Tacoma Intl
9h 35m
LHR10:30 a.m.London Heathrow
C$ 899
Find similar
Delta
20 Mar
LHR6:20 a.m.London Heathrow
14h 45m
1 stop
SEA2:05 p.m.Seattle/Tacoma Intl
30 Mar
SEA3:35 p.m.Seattle/Tacoma Intl
9h 25m
LHR9:00 a.m.London Heathrow
C$ 910
Find similar

United Airlines flights from London to Seattle

Our best United Airlines deals on London to Seattle flight tickets
United Airlines
10 Feb
LHR4:40 p.m.London Heathrow
28h 40m
1 stop
SEA1:20 p.m.Seattle/Tacoma Intl
18 Feb
SEA5:00 a.m.Seattle/Tacoma Intl
20h 40m
1 stop
LHR9:40 a.m.London Heathrow
C$ 929
Find similar
United Airlines
9 Feb
LHR6:30 a.m.London Heathrow
13h 40m
1 stop
SEA12:10 p.m.Seattle/Tacoma Intl
18 Feb
SEA7:00 a.m.Seattle/Tacoma Intl
16h 55m
1 stop
LHR7:55 a.m.London Heathrow
C$ 931
Find similar
United Airlines
26 Nov
LHR1:30 p.m.London Heathrow
18h 14m
2 stops
SEA11:44 p.m.Seattle/Tacoma Intl
3 Dec
SEA1:05 p.m.Seattle/Tacoma Intl
16h 25m
2 stops
LHR1:30 p.m.London Heathrow
C$ 933
Find similar

momondo Fare Finder

 
Customize 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 96,600 searches. Data last updated 30 October 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

Thu 19/3

12:15 p.m.-6:00 p.m.

1 stop12h 45m

Seattle/Tacoma Intl

Mon 30/3

3:45 p.m.-11:55 a.m.

1 stop12h 10m

C$ 874

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 21/3

8:35 p.m.-6:00 p.m.

1 stop28h 25m

Seattle/Tacoma Intl

Thu 26/3

3:35 p.m.-10:50 a.m.

1 stop12h 15m

C$ 877

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 8/2

8:40 a.m.-11:40 a.m.

1 stop35h 00m

Seattle/Tacoma Intl

Wed 18/2

7:20 a.m.-6:50 a.m.

1 stop15h 30m

C$ 892

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 7/2

6:20 a.m.-11:25 a.m.

1 stop13h 05m

Seattle/Tacoma Intl

Wed 18/2

4:55 p.m.-10:30 a.m.

Nonstop9h 35m

C$ 899

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 21/3

9:25 a.m.-12:30 p.m.

Nonstop10h 05m

Seattle/Tacoma Intl

Sat 28/3

2:35 p.m.-7:10 a.m.

Nonstop9h 35m

C$ 915

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 24/2

6:30 a.m.-11:40 a.m.

1 stop13h 10m

Seattle/Tacoma Intl

Sun 8/3

5:40 p.m.-10:30 a.m.

Nonstop9h 50m

C$ 924

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/2

4:40 p.m.-1:20 p.m.

1 stop28h 40m

Seattle/Tacoma Intl

Wed 18/2

5:00 a.m.-9:40 a.m.

1 stop20h 40m

C$ 929

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 5/2

2:55 p.m.-4:55 p.m.

Nonstop10h 00m

Seattle/Tacoma Intl

Wed 18/2

6:50 p.m.-12:20 p.m.

Nonstop9h 30m

C$ 930

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 9/2

6:30 a.m.-12:10 p.m.

1 stop13h 40m

Seattle/Tacoma Intl

Wed 18/2

7:00 a.m.-7:55 a.m.

1 stop16h 55m

C$ 931

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 12/11

6:30 a.m.-11:45 a.m.

1 stop13h 15m

Seattle/Tacoma Intl

Wed 19/11

4:48 p.m.-10:30 a.m.

Nonstop9h 42m

C$ 1,005

Flights are sorted by cheapest round-trip 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?

If you aren’t able to travel to Seattle during the month of January, then flying in February is also cheap. Prices for this month can be found on momondo for an average of C$ 924.

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

Our data shows that Monday is the least expensive day to fly to Seattle. Tickets to fly out on this day can be as low as C$ 1,066. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around C$ 1,612. These prices are subject to change though, so be sure to set up a Price Alert for flights to Seattle.

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

Our most recent data shows that the best time of day to fly to Seattle is in the afternoon. Flights from London to Seattle during this time can be as low as C$ 1,066. Flights at noon are often more expensive with an average ticket price of C$ 1,332.

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 C$ 1,083 when searching 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 C$ 1,014 on momondo.

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

There are 3 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 October 2025, prices for London to Seattle flights are approximately 6% 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 round-trip 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

Fastest flight time

9h 45m

Direct flights

Every day

Airports in Seattle

1 airport
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)
Search flight deals

  • How far is London to Seattle/Tacoma Intl by plane?

    The straight-line distance from London to Seattle/Tacoma Intl is 7694.7 km. In terms of flight time, this usually takes a little over 9h 55m.

  • 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 refresh daily.

  • 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 offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify 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 required for your trip to Seattle/Tacoma Intl Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Seattle/Tacoma Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

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

Travelling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Leavenworth
Lynnwood
Marysville
Tacoma
SeaTac
Kirkland
Olympia
Ocean Shores
Redmond
Shoreline
Ellensburg
Gig Harbor
Renton
Mukilteo
Cle Elum
Centralia
Federal Way
Puyallup
Shelton
Lakewood

Why use momondo?

Why should I use momondo to find a flight deal from London to Seattle?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from London to Seattle . Millions of users trust and use momondo every year so you are in good hands.

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

Yes. momondo enables you to select and highlight flights to Seattle from London with this policy.

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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