Latest deals
Insights
When to book
FAQs
Price Alerts

Cheap flights from London to Seattle from C$ 684

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 13/9. 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

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? Early arrival? Instantly customize 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.
Search flight deals

Find the cheapest flights from London to Seattle

Cheap round-trip flights

Icelandair Logo
9:25 p.m. - 11:25 a.m.LHR-SEA
22h 00m1 stop
Icelandair Logo
3:45 p.m. - 11:55 a.m.SEA-LHR
12h 10m1 stop
C$ 808Icelandair
Find Deal
Tue, 9 Sep - Sat, 27 Sep
Icelandair Logo
12:15 p.m. - 6:00 p.m.LHR-SEA
12h 45m1 stop
Icelandair Logo
2:35 p.m. - 10:50 a.m.SEA-LHR
12h 15m1 stop
C$ 810Icelandair
Find Deal
Wed, 29 Oct - Sun, 9 Nov
United Airlines Logo
1:05 p.m. - 1:30 p.m.LHR-SEA
32h 25m1 stop
United Airlines Logo
7:00 a.m. - 6:20 a.m.SEA-LHR
15h 20m1 stop
C$ 850United Airlines
Find Deal
Sat, 23 Aug - Mon, 25 Aug
SWISS Logo
8:05 p.m. - 6:36 p.m.LHR-SEA
30h 31m2 stops
SWISS Logo
3:28 p.m. - 5:50 p.m.SEA-LHR
18h 22m2 stops
C$ 863SWISS
Find Deal
Wed, 10 Sep - Tue, 30 Sep
United Airlines Logo
10:50 a.m. - 4:59 p.m.LHR-SEA
14h 09m1 stop
United Airlines Logo
8:00 a.m. - 11:45 a.m.SEA-LHR
19h 45m2 stops
C$ 865United Airlines
Find Deal
Wed, 27 Aug - Tue, 9 Sep
Lufthansa Logo
6:30 a.m. - 12:10 p.m.LHR-SEA
13h 40m1 stop
Lufthansa Logo
10:05 a.m. - 11:50 a.m.SEA-LHR
17h 45m1 stop
C$ 869Lufthansa
Find Deal
Tue, 18 Nov - Fri, 21 Nov
SWISS Logo
9:00 a.m. - 8:59 p.m.LHR-SEA
19h 59m2 stops
SWISS Logo
11:05 a.m. - 1:00 p.m.SEA-LHR
17h 55m2 stops
C$ 870SWISS
Find Deal
Tue, 13 Jan - Tue, 27 Jan
Austrian Airlines Logo
7:30 p.m. - 8:42 p.m.LHR-SEA
33h 12m2 stops
Austrian Airlines Logo
8:00 a.m. - 6:20 a.m.SEA-LHR
38h 20m2 stops
C$ 872Austrian Airlines
Find Deal
Sun, 14 Sep - Sun, 21 Sep
Austrian Airlines Logo
6:00 a.m. - 6:52 p.m.LHR-SEA
20h 52m2 stops
Austrian Airlines Logo
8:00 a.m. - 11:15 a.m.SEA-LHR
19h 15m2 stops
C$ 873Austrian Airlines
Find Deal
Wed, 26 Nov - Thu, 26 Feb
Lufthansa Logo
6:30 a.m. - 11:55 a.m.LHR-SEA
13h 25m1 stop
Lufthansa Logo
2:20 p.m. - 10:40 a.m.SEA-LHR
12h 20m1 stop
C$ 921Lufthansa
Find Deal
Tue, 30 Sep - Mon, 13 Oct

SWISS flights from London to Seattle

Our best SWISS deals on London to Seattle flight tickets
SWISS
10 Sep
LHR8:05 p.m.London Heathrow
30h 31m
2 stops
SEA6:36 p.m.Seattle/Tacoma Intl
30 Sep
SEA3:28 p.m.Seattle/Tacoma Intl
18h 22m
2 stops
LHR5:50 p.m.London Heathrow
C$ 863
Find similar
SWISS
13 Jan
LHR9:00 a.m.London Heathrow
19h 59m
2 stops
SEA8:59 p.m.Seattle/Tacoma Intl
27 Jan
SEA11:05 a.m.Seattle/Tacoma Intl
17h 55m
2 stops
LHR1:00 p.m.London Heathrow
C$ 870
Find similar
SWISS
5 Sep
LHR6:00 a.m.London Heathrow
20h 36m
2 stops
SEA6:36 p.m.Seattle/Tacoma Intl
22 Sep
SEA2:29 p.m.Seattle/Tacoma Intl
20h 51m
2 stops
LHR7:20 p.m.London Heathrow
C$ 875
Find similar

United Airlines flights from London to Seattle

Our best United Airlines deals on London to Seattle flight tickets
United Airlines
23 Aug
LHR1:05 p.m.London Heathrow
32h 25m
1 stop
SEA1:30 p.m.Seattle/Tacoma Intl
25 Aug
SEA7:00 a.m.Seattle/Tacoma Intl
15h 20m
1 stop
LHR6:20 a.m.London Heathrow
C$ 850
Find similar
United Airlines
27 Aug
LHR10:50 a.m.London Heathrow
14h 09m
1 stop
SEA4:59 p.m.Seattle/Tacoma Intl
9 Sep
SEA8:00 a.m.Seattle/Tacoma Intl
19h 45m
2 stops
LHR11:45 a.m.London Heathrow
C$ 865
Find similar
United Airlines
5 Sep
LHR7:25 a.m.London Heathrow
17h 34m
1 stop
SEA4:59 p.m.Seattle/Tacoma Intl
15 Sep
SEA8:00 a.m.Seattle/Tacoma Intl
19h 45m
2 stops
LHR11:45 a.m.London Heathrow
C$ 866
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 31 July 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

Tue 9/9

9:25 p.m.-11:25 a.m.

1 stop22h 00m

Seattle/Tacoma Intl

Sat 27/9

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

1 stop12h 10m

C$ 808

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 29/10

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

1 stop12h 45m

Seattle/Tacoma Intl

Sun 9/11

2:35 p.m.-10:50 a.m.

1 stop12h 15m

C$ 810

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 23/8

1:05 p.m.-1:30 p.m.

1 stop32h 25m

Seattle/Tacoma Intl

Mon 25/8

7:00 a.m.-6:20 a.m.

1 stop15h 20m

C$ 850

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 10/9

8:05 p.m.-6:36 p.m.

2 stops30h 31m

Seattle/Tacoma Intl

Tue 30/9

3:28 p.m.-5:50 p.m.

2 stops18h 22m

C$ 863

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 27/8

10:50 a.m.-4:59 p.m.

1 stop14h 09m

Seattle/Tacoma Intl

Tue 9/9

8:00 a.m.-11:45 a.m.

2 stops19h 45m

C$ 865

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 18/11

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

1 stop13h 40m

Seattle/Tacoma Intl

Fri 21/11

10:05 a.m.-11:50 a.m.

1 stop17h 45m

C$ 869

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 13/1

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

2 stops19h 59m

Seattle/Tacoma Intl

Tue 27/1

11:05 a.m.-1:00 p.m.

2 stops17h 55m

C$ 870

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 14/9

7:30 p.m.-8:42 p.m.

2 stops33h 12m

Seattle/Tacoma Intl

Sun 21/9

8:00 a.m.-6:20 a.m.

2 stops38h 20m

C$ 872

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 26/11

6:00 a.m.-6:52 p.m.

2 stops20h 52m

Seattle/Tacoma Intl

Thu 26/2

8:00 a.m.-11:15 a.m.

2 stops19h 15m

C$ 873

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 30/9

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

1 stop13h 25m

Seattle/Tacoma Intl

Mon 13/10

2:20 p.m.-10:40 a.m.

1 stop12h 20m

C$ 921

Flights are sorted by cheapest round-trip 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?

If you aren’t able to travel to Seattle during the month of January, then flying in March is also cheap. Prices for this month can be found on momondo for an average of C$ 906.

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

Our data shows that Tuesday is the least expensive day to fly to Seattle. Tickets to fly out on this day can be as low as C$ 1,021. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around C$ 1,881. 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$ 1,237. Flights in the morning are often more expensive with an average ticket price of C$ 1,881.

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$ 1,073 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$ 971 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 39% 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 July 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$ 684

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$ 684. The best round-trip flight deal from London to Seattle found on momondo in the last 72 hours is C$ 808.
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 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 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
Marysville
Lynnwood
SeaTac
Tacoma
Olympia
Ellensburg
Kirkland
Redmond
Ocean Shores
Shoreline
Tukwila
Renton
Mukilteo
Gig Harbor
Cle Elum
Poulsbo
Puyallup
Centralia
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.

An easier way to manage your Seattle trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Tue 5/8
Tue 12/8
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States