Latest deals
Insights
When to book
FAQs
Price Alerts

Cheap flights from London Heathrow Airport to Seattle from C$ 728

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 Heathrow Airport to Seattle departing on 31/1. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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 Heathrow Airport to Seattle

Cheap round-trip flights

Enter your travel dates to find the best prices.
Icelandair Logo
12:15 p.m. - 5:00 p.m.
LHR
-
SEA
12h 45m1 stop
Icelandair Logo
3:35 p.m. - 10:50 a.m.
SEA
-
LHR
12h 15m1 stop
C$ 826Icelandair
Sun, 1 Feb - Sun, 8 Mar
Icelandair Logo
12:15 p.m. - 5:00 p.m.
LHR
-
SEA
12h 45m1 stop
Icelandair Logo
2:35 p.m. - 10:50 a.m.
SEA
-
LHR
12h 15m1 stop
C$ 854Icelandair
Tue, 10 Feb - Thu, 19 Feb
Icelandair Logo
8:35 p.m. - 5:00 p.m.
LHR
-
SEA
28h 25m1 stop
Icelandair Logo
2:35 p.m. - 10:50 a.m.
SEA
-
LHR
12h 15m1 stop
C$ 856Icelandair
Thu, 12 Feb - Thu, 19 Feb
Icelandair Logo
8:35 p.m. - 5:00 p.m.
LHR
-
SEA
28h 25m1 stop
Icelandair Logo
2:35 p.m. - 7:30 p.m.
SEA
-
LHR
20h 55m1 stop
C$ 877Icelandair
Sun, 18 Jan - Sat, 24 Jan
Icelandair Logo
12:15 p.m. - 5:00 p.m.
LHR
-
SEA
12h 45m1 stop
Icelandair Logo
2:35 p.m. - 7:30 p.m.
SEA
-
LHR
20h 55m1 stop
C$ 901Icelandair
Tue, 10 Feb - Sun, 15 Feb
Icelandair Logo
8:35 p.m. - 5:00 p.m.
LHR
-
SEA
28h 25m1 stop
Icelandair Logo
2:35 p.m. - 7:30 p.m.
SEA
-
LHR
20h 55m1 stop
C$ 902Icelandair
Sat, 24 Jan - Thu, 29 Jan
SWISS Logo
8:05 p.m. - 9:12 p.m.
LHR
-
SEA
33h 07m2 stops
SWISS Logo
7:00 a.m. - 7:55 a.m.
SEA
-
LHR
16h 55m2 stops
C$ 964SWISS
Wed, 21 Jan - Wed, 30 Sep
Lufthansa Logo
6:35 a.m. - 1:20 p.m.
LHR
-
SEA
14h 45m1 stop
Lufthansa Logo
2:10 p.m. - 3:50 p.m.
SEA
-
LHR
17h 40m2 stops
C$ 969Lufthansa
Wed, 21 Jan - Tue, 27 Jan
United Airlines Logo
6:30 a.m. - 1:10 p.m.
LHR
-
SEA
13h 40m1 stop
United Airlines Logo
8:00 a.m. - 7:30 a.m.
SEA
-
LHR
40h 30m2 stops
C$ 972United Airlines
Tue, 10 Mar - Tue, 17 Mar
United Airlines Logo
7:30 a.m. - 6:26 p.m.
LHR
-
SEA
18h 56m2 stops
United Airlines Logo
5:00 a.m. - 7:10 a.m.
SEA
-
LHR
18h 10m2 stops
C$ 976United Airlines
Tue, 3 Feb - Thu, 5 Mar

Icelandair flights from London Heathrow Airport to Seattle

Our best Icelandair deals on London Heathrow Airport to Seattle flight tickets
Icelandair
1 Feb
LHR12:15 p.m.London Heathrow
12h 45m
1 stop
SEA5:00 p.m.Seattle/Tacoma Intl
8 Mar
SEA3:35 p.m.Seattle/Tacoma Intl
12h 15m
1 stop
LHR10:50 a.m.London Heathrow
C$ 826
Find similar
Icelandair
10 Feb
LHR12:15 p.m.London Heathrow
12h 45m
1 stop
SEA5:00 p.m.Seattle/Tacoma Intl
19 Feb
SEA2:35 p.m.Seattle/Tacoma Intl
12h 15m
1 stop
LHR10:50 a.m.London Heathrow
C$ 854
Find similar
Icelandair
12 Feb
LHR8:35 p.m.London Heathrow
28h 25m
1 stop
SEA5:00 p.m.Seattle/Tacoma Intl
19 Feb
SEA2:35 p.m.Seattle/Tacoma Intl
12h 15m
1 stop
LHR10:50 a.m.London Heathrow
C$ 856
Find similar

United Airlines flights from London Heathrow Airport to Seattle

Our best United Airlines deals on London Heathrow Airport to Seattle flight tickets
United Airlines
10 Mar
LHR6:30 a.m.London Heathrow
13h 40m
1 stop
SEA1:10 p.m.Seattle/Tacoma Intl
17 Mar
SEA8:00 a.m.Seattle/Tacoma Intl
40h 30m
2 stops
LHR7:30 a.m.London Heathrow
C$ 972
Find similar
United Airlines
3 Feb
LHR7:30 a.m.London Heathrow
18h 56m
2 stops
SEA6:26 p.m.Seattle/Tacoma Intl
5 Mar
SEA5:00 a.m.Seattle/Tacoma Intl
18h 10m
2 stops
LHR7:10 a.m.London Heathrow
C$ 976
Find similar
United Airlines
14 Jan
LHR11:05 a.m.London Heathrow
56h 27m
2 stops
SEA11:32 a.m.Seattle/Tacoma Intl
17 Jan
SEA9:00 a.m.Seattle/Tacoma Intl
40h 40m
2 stops
LHR9:40 a.m.London Heathrow
C$ 987
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from London Heathrow Airport 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 December 2025.
Use the filters below to find and compare flights from London Heathrow Airport to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 1/2

12:15 p.m.-5:00 p.m.

1 stop12h 45m

Seattle/Tacoma Intl

Sun 8/3

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

1 stop12h 15m

C$ 826

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/2

12:15 p.m.-5:00 p.m.

1 stop12h 45m

Seattle/Tacoma Intl

Thu 19/2

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

1 stop12h 15m

C$ 854

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 12/2

8:35 p.m.-5:00 p.m.

1 stop28h 25m

Seattle/Tacoma Intl

Thu 19/2

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

1 stop12h 15m

C$ 856

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 18/1

8:35 p.m.-5:00 p.m.

1 stop28h 25m

Seattle/Tacoma Intl

Sat 24/1

2:35 p.m.-7:30 p.m.

1 stop20h 55m

C$ 877

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/2

12:15 p.m.-5:00 p.m.

1 stop12h 45m

Seattle/Tacoma Intl

Sun 15/2

2:35 p.m.-7:30 p.m.

1 stop20h 55m

C$ 901

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 24/1

8:35 p.m.-5:00 p.m.

1 stop28h 25m

Seattle/Tacoma Intl

Thu 29/1

2:35 p.m.-7:30 p.m.

1 stop20h 55m

C$ 902

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 21/1

8:05 p.m.-9:12 p.m.

2 stops33h 07m

Seattle/Tacoma Intl

Wed 30/9

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

2 stops16h 55m

C$ 964

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 21/1

6:35 a.m.-1:20 p.m.

1 stop14h 45m

Seattle/Tacoma Intl

Tue 27/1

2:10 p.m.-3:50 p.m.

2 stops17h 40m

C$ 969

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/3

6:30 a.m.-1:10 p.m.

1 stop13h 40m

Seattle/Tacoma Intl

Tue 17/3

8:00 a.m.-7:30 a.m.

2 stops40h 30m

C$ 972

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 3/2

7:30 a.m.-6:26 p.m.

2 stops18h 56m

Seattle/Tacoma Intl

Thu 5/3

5:00 a.m.-7:10 a.m.

2 stops18h 10m

C$ 976

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 Heathrow Airport 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 Heathrow Airport and Seattle?

What is the cheapest month to fly to Seattle?

If you aren’t able to travel to Seattle during the month of February, then flying in September is also cheap. Prices for this month can be found on momondo for an average of C$ 947.

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$ 1,051. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around C$ 1,235. 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 Heathrow Airport to Seattle during this time can be as low as C$ 1,043. Flights at noon are often more expensive with an average ticket price of C$ 1,314.

What is the cheapest London Heathrow to Seattle/Tacoma Intl flight route?

Fly from London Heathrow to Seattle/Tacoma Intl for the best London Heathrow - 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 Heathrow Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around C$ 1,051 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from London Heathrow Airport for as low as C$ 962 on momondo.

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

There are 3 cabin classes available to choose from on London Heathrow 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 Heathrow Airport to Seattle flights?

You could potentially save up to 20% on your flight if you consider stops on a London Heathrow Airport to Seattle flight.

How have London Heathrow Airport to Seattle flight prices changed over time?

As of December 2025, prices for London Heathrow Airport to Seattle flights are approximately 16% more expensive when compared to flights at the same time last year.

When to book flights from London Heathrow Airport to Seattle

Are you open to changing your travel dates? Check out the ideal times to fly from London Heathrow Airport to Seattle according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap London Heathrow Airport to Seattle (LHR to SEA) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from London Heathrow Airport to Seattle

Fastest flight time

10h 20m

Direct flights

Every day

Airports in Seattle

1 airport
The fastest flight from London Heathrow Airport to Seattle takes 10h 20m
Direct flights go from London Heathrow Airport to Seattle every day.
There is 1 airport in Seattle. From London Heathrow Airport there are direct flights to Seattle/Tacoma Intl (SEA).
Search flight deals

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

    London Heathrow and Seattle/Tacoma Intl are 7683.2 km apart from one another. By plane, this route typically takes 10h 20m.

  • When did momondo last update prices for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport?

    Prices for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport are updated daily.

  • How old do you have to be to fly from London Heathrow Airport to Seattle/Tacoma Intl Airport?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from London Heathrow Airport to Seattle/Tacoma Intl Airport.

  • What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

    The necessary travel and health documents for your Seattle/Tacoma Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from London Heathrow Airport 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
Tukwila
Olympia
Ocean Shores
Redmond
Bainbridge Island
Ellensburg
Gig Harbor
Renton
Mukilteo
Cle Elum
Centralia
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. All flights to Seattle from London on momondo can be compared and filtered by various policies on offer, including flexible booking.

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 offers price alerts on flights to Seattle from London. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

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
Wed 14/1
Wed 21/1
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States