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Cheap flights from London to Seattle from C$ 727

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 25/11. 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

Lufthansa Logo
6:30 a.m. - 11:55 a.m.LHR-SEA
13h 25m1 stop
Lufthansa Logo
3:40 p.m. - 11:50 a.m.SEA-LHR
12h 10m1 stop
C$ 837Lufthansa
Find Deal
Thu, 25 Sep - Wed, 5 Nov
United Airlines Logo
7:30 a.m. - 10:42 p.m.LHR-SEA
23h 12m2 stops
United Airlines Logo
11:59 p.m. - 7:10 a.m.SEA-LHR
23h 11m2 stops
C$ 839United Airlines
Find Deal
Sat, 15 Nov - Fri, 21 Nov
SWISS Logo
8:40 a.m. - 9:15 p.m.LHR-SEA
20h 35m2 stops
SWISS Logo
1:20 p.m. - 5:50 p.m.SEA-LHR
20h 30m2 stops
C$ 840SWISS
Find Deal
Thu, 25 Sep - Wed, 5 Nov
Icelandair Logo
1:05 p.m. - 5:50 p.m.LHR-SEA
12h 45m1 stop
Icelandair Logo
3:45 p.m. - 11:55 a.m.SEA-LHR
12h 10m1 stop
C$ 846Icelandair
Find Deal
Thu, 2 Oct - Mon, 13 Oct
Icelandair Logo
9:25 p.m. - 5:50 p.m.LHR-SEA
28h 25m1 stop
Icelandair Logo
3:45 p.m. - 11:55 a.m.SEA-LHR
12h 10m1 stop
C$ 848Icelandair
Find Deal
Sun, 5 Oct - Mon, 13 Oct
British Airways Logo
8:20 a.m. - 4:54 p.m.LHR-SEA
16h 34m1 stop
British Airways Logo
3:49 p.m. - 6:25 a.m.SEA-LHR
30h 36m1 stop
C$ 865British Airways
Find Deal
Tue, 7 Oct - Sun, 12 Oct
Delta Logo
6:30 a.m. - 4:05 p.m.LHR-SEA
17h 35m1 stop
Delta Logo
5:35 p.m. - 11:20 a.m.SEA-LHR
9h 45mdirect
C$ 866Delta
Find Deal
Wed, 8 Oct - Tue, 14 Oct
British Airways Logo
10:05 a.m. - 7:27 p.m.LHR-SEA
16h 22m1 stop
British Airways Logo
1:25 p.m. - 7:00 a.m.SEA-LHR
9h 35mdirect
C$ 873British Airways
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Tue, 28 Oct - Tue, 4 Nov
Delta Logo
5:25 p.m. - 7:50 p.m.LHR-SEA
10h 25mdirect
Delta Logo
9:59 p.m. - 8:00 p.m.SEA-LHR
14h 01m1 stop
C$ 890Delta
Find Deal
Mon, 6 Oct - Sun, 12 Oct
SWISS Logo
9:00 a.m. - 11:15 p.m.LHR-SEA
22h 15m2 stops
SWISS Logo
10:58 a.m. - 11:15 a.m.SEA-LHR
40h 17m2 stops
C$ 904SWISS
Find Deal
Tue, 16 Dec - Tue, 6 Jan

Delta flights from London to Seattle

Our best Delta deals on London to Seattle flight tickets
Delta
22 Sep
LHR8:40 a.m.London Heathrow
15h 25m
1 stop
SEA4:05 p.m.Seattle/Tacoma Intl
6 Oct
SEA8:25 p.m.Seattle/Tacoma Intl
9h 50m
LHR2:15 p.m.London Heathrow
C$ 865
Find similar
Delta
8 Oct
LHR6:30 a.m.London Heathrow
17h 35m
1 stop
SEA4:05 p.m.Seattle/Tacoma Intl
14 Oct
SEA5:35 p.m.Seattle/Tacoma Intl
9h 45m
LHR11:20 a.m.London Heathrow
C$ 866
Find similar
Delta
6 Oct
LHR5:25 p.m.London Heathrow
10h 25m
SEA7:50 p.m.Seattle/Tacoma Intl
12 Oct
SEA9:59 p.m.Seattle/Tacoma Intl
14h 01m
1 stop
LHR8:00 p.m.London Heathrow
C$ 890
Find similar

British Airways flights from London to Seattle

Our best British Airways deals on London to Seattle flight tickets
British Airways
7 Oct
LHR8:20 a.m.London Heathrow
16h 34m
1 stop
SEA4:54 p.m.Seattle/Tacoma Intl
12 Oct
SEA3:49 p.m.Seattle/Tacoma Intl
30h 36m
1 stop
LHR6:25 a.m.London Heathrow
C$ 865
Find similar
British Airways
28 Oct
LHR10:05 a.m.London Heathrow
16h 22m
1 stop
SEA7:27 p.m.Seattle/Tacoma Intl
4 Nov
SEA1:25 p.m.Seattle/Tacoma Intl
9h 35m
LHR7:00 a.m.London Heathrow
C$ 873
Find similar
British Airways
4 Oct
LHR10:30 a.m.London Heathrow
18h 53m
1 stop
SEA9:23 p.m.Seattle/Tacoma Intl
8 Oct
SEA1:53 p.m.Seattle/Tacoma Intl
16h 32m
1 stop
LHR2:25 p.m.London Heathrow
C$ 922
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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 15 September 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 25/9

6:30 a.m.-11:55 a.m.

1 stop13h 25m

Seattle/Tacoma Intl

Wed 5/11

3:40 p.m.-11:50 a.m.

1 stop12h 10m

C$ 837

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 15/11

7:30 a.m.-10:42 p.m.

2 stops23h 12m

Seattle/Tacoma Intl

Fri 21/11

11:59 p.m.-7:10 a.m.

2 stops23h 11m

C$ 839

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 25/9

8:40 a.m.-9:15 p.m.

2 stops20h 35m

Seattle/Tacoma Intl

Wed 5/11

1:20 p.m.-5:50 p.m.

2 stops20h 30m

C$ 840

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 2/10

1:05 p.m.-5:50 p.m.

1 stop12h 45m

Seattle/Tacoma Intl

Mon 13/10

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

1 stop12h 10m

C$ 846

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 5/10

9:25 p.m.-5:50 p.m.

1 stop28h 25m

Seattle/Tacoma Intl

Mon 13/10

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

1 stop12h 10m

C$ 848

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 7/10

8:20 a.m.-4:54 p.m.

1 stop16h 34m

Seattle/Tacoma Intl

Sun 12/10

3:49 p.m.-6:25 a.m.

1 stop30h 36m

C$ 865

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 8/10

6:30 a.m.-4:05 p.m.

1 stop17h 35m

Seattle/Tacoma Intl

Tue 14/10

5:35 p.m.-11:20 a.m.

Nonstop9h 45m

C$ 866

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 28/10

10:05 a.m.-7:27 p.m.

1 stop16h 22m

Seattle/Tacoma Intl

Tue 4/11

1:25 p.m.-7:00 a.m.

Nonstop9h 35m

C$ 873

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 6/10

5:25 p.m.-7:50 p.m.

Nonstop10h 25m

Seattle/Tacoma Intl

Sun 12/10

9:59 p.m.-8:00 p.m.

1 stop14h 01m

C$ 890

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 16/12

9:00 a.m.-11:15 p.m.

2 stops22h 15m

Seattle/Tacoma Intl

Tue 6/1

10:58 a.m.-11:15 a.m.

2 stops40h 17m

C$ 904

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$ 915.

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$ 1,056. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around C$ 1,598. 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$ 1,056. Flights in the morning are often more expensive with an average ticket price of C$ 1,491.

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$ 1,063 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$ 961 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 28% 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 September 2025, prices for London to Seattle flights are approximately 3% 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 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

Best price found

C$ 1,030

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 C$ 1,030. The best round-trip flight deal from London to Seattle found on momondo in the last 72 hours is C$ 1,057.
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 10h 05m.

  • 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
Redmond
Olympia
Ocean Shores
Shoreline
Ellensburg
Tukwila
Gig Harbor
Renton
Mukilteo
Cle Elum
Poulsbo
Puyallup
Federal Way
Kent

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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