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Cheap flights from London Heathrow Airport to Seattle from C$ 650

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 18/3. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
5 Mar — 12 Mar1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from London Heathrow to Seattle/Tacoma Intl are usually found in February or January, booked 62 days in advance, depart on a Monday or Tuesday and return on a Sunday

Cheap flight deals from Heathrow to Seattle

Enter your travel dates to find the best prices.

Cheapest flights from Heathrow to Seattle
Explore the most affordable flight options available from Heathrow to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 3 February 2026.

Mon 16/26:30 a.m.
LHR
-
SEA
1 stop13h 40m
Lufthansa
Mon 2/33:40 p.m.
SEA
-
LHR
1 stop12h 10m
Lufthansa
Deal found 1/2C$ 687
Fri 9/109:25 p.m.
LHR
-
SEA
1 stop31h 15m
Icelandair
Thu 15/103:40 p.m.
SEA
-
LHR
1 stop12h 15m
Icelandair
Deal found 1/2C$ 698
Sun 15/27:40 a.m.
LHR
-
SEA
1 stop13h 40m
Lufthansa
Wed 18/23:10 p.m.
SEA
-
LHR
1 stop16h 40m
Lufthansa
Deal found 1/2C$ 710
Mon 16/26:30 a.m.
LHR
-
SEA
1 stop13h 10m
Delta
Mon 2/311:35 a.m.
SEA
-
LHR
1 stop15h 05m
Delta
Deal found 2/2C$ 717
Mon 16/26:30 a.m.
LHR
-
SEA
1 stop13h 10m
Delta
Sun 22/211:15 p.m.
SEA
-
LHR
1 stop25h 30m
Delta
Deal found 2/2C$ 725
Fri 20/26:35 a.m.
LHR
-
SEA
1 stop14h 45m
Lufthansa
Tue 24/27:00 a.m.
SEA
-
LHR
1 stop14h 55m
Lufthansa
Deal found 2/2C$ 736
Thu 19/26:30 a.m.
LHR
-
SEA
1 stop13h 40m
Lufthansa
Tue 24/29:55 a.m.
SEA
-
LHR
2 stops16h 15m
Lufthansa
Deal found 2/2C$ 737
Wed 29/49:55 a.m.
LHR
-
SEA
1 stop14h 35m
Delta
Mon 11/56:20 p.m.
SEA
-
LHR
Nonstop9h 50m
Delta
Deal found 1/2C$ 739
Tue 17/212:20 p.m.
LHR
-
SEA
Nonstop10h 25m
Delta
Tue 24/26:25 p.m.
SEA
-
LHR
Nonstop9h 30m
Delta
Deal found 2/2C$ 742
Tue 17/36:35 a.m.
LHR
-
SEA
2 stops21h 39m
United Airlines
Tue 24/311:59 p.m.
SEA
-
LHR
1 stop14h 21m
United Airlines
Deal found 1/2C$ 743

Find flight deals from Heathrow to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from Heathrow (LHR) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 3 February 2026.

Round-trip from

C$ 687

One-way from

C$ 650

Popular in

July

Cheapest in

February

Average price

C$ 844

Good round-trip deal

C$ 1,042 or less

Good one-way deal

C$ 1,149 or less
Lufthansa
  • Lufthansa
  • 16/2-2/3
  • 2 total stops
  • 25h 50m total
  • London to Seattle
Search Deals
SWISS
  • SWISS
  • 18/3
  • 2 total stops
  • 21h 28m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (C$ 203 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 33 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 2026
Search Deals
Price to beat on a round-trip flight from London Heathrow to Seattle/Tacoma Intl.
Search Deals
Price to beat on a one-way flight from London Heathrow to Seattle/Tacoma Intl.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Heathrow 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, Cheapflights users made 629,999 searches. Data last updated 3 February 2026.
Use the filters below to find and compare flights from London Heathrow Airport to Seattle that are best for you.

Fly from

Heathrow

Fly to

Seattle

Route

Depart

Return

Price

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 16/2

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

1 stop13h 10m

Seattle/Tacoma Intl

Mon 2/3

4:45 p.m.-10:30 a.m.

Nonstop9h 45m

C$ 717

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 2/3

6:30 a.m.-11:35 a.m.

1 stop13h 05m

Seattle/Tacoma Intl

Mon 16/3

7:25 p.m.-11:55 a.m.

Nonstop9h 30m

C$ 718

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 18/2

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

1 stop14h 45m

Seattle/Tacoma Intl

Sat 21/2

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

1 stop16h 55m

C$ 736

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 5/5

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

1 stop18h 00m

Seattle/Tacoma Intl

Mon 11/5

5:30 a.m.-7:10 a.m.

1 stop17h 40m

C$ 739

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 10/3

12:20 p.m.-3:40 p.m.

Nonstop10h 20m

Seattle/Tacoma Intl

Tue 17/3

7:25 p.m.-11:55 a.m.

Nonstop9h 30m

C$ 742

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 10/5

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

1 stop14h 09m

Seattle/Tacoma Intl

Tue 12/5

8:00 a.m.-6:55 a.m.

1 stop14h 55m

C$ 758

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 9/3

7:30 a.m.-6:04 p.m.

2 stops17h 34m

Seattle/Tacoma Intl

Mon 16/3

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

2 stops16h 20m

C$ 766

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 17/2

2:30 p.m.-9:15 a.m.

1 stop26h 45m

Seattle/Tacoma Intl

Fri 20/2

12:55 p.m.-9:40 a.m.

1 stop12h 45m

C$ 781

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 29/4

9:15 a.m.-12:44 a.m.

2 stops23h 29m

C$ 679

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 29/4

7:25 a.m.-11:27 p.m.

3 stops24h 02m

C$ 688

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/2

Showing 1-10 of 18 results
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Best time to book a flight from Heathrow to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Heathrow with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from London Heathrow Airport to Seattle

How far ahead should I book a flight from London Heathrow Airport to Seattle?

Use this chart to determine the optimal time to book a round-trip flight from Heathrow to Seattle. Price data was last updated on 30 January 2026.

The price you pay for your flight from London Heathrow Airport to Seattle may vary depending on when you book. For the best chance of a lower fare, look to book 62 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from London Heathrow Airport to Seattle?

Currently, January is the cheapest month in which you can book a flight from London Heathrow Airport to Seattle (average of C$ 687). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of C$ 923). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from LHR to SEA?

Find hourly flight availability from Heathrow to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 3 February 2026.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from London Heathrow Airport to Seattle as you normally would.

How much does it cost to fly round-trip from London Heathrow Airport to Seattle?

Related info for your journey

Find useful and relevant information for your journey from Heathrow to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Seattle from London Heathrow?

    Seattle/Tacoma Intl (SEA), located 18.4 km from the city centre, is the airport you fly into when you book flights from London Heathrow to Seattle. 0 airlines have flights to Seattle/Tacoma Intl from London Heathrow on a regular basis. Booking flights from London Heathrow to Seattle/Tacoma Intl should not be difficult; the airport handles an average of 15 inbound flights from London Heathrow per day.

  • How long is the flight from London Heathrow Airport to Seattle?

    A quick flight from London Heathrow Airport to Seattle can take about 13h 05m. Delta provides one of the quickest options available for as low as C$ 718. There are 7697 km between London Heathrow Airport and Seattle. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • What are the most reliable airlines from London Heathrow Airport to Seattle?

    Consider KLM (89%), Air France (89%) or Delta (89%) when booking your flight. These represent the most reliable airlines when flying from London Heathrow Airport to Seattle.

  • What are the cheapest flights from London Heathrow Airport to Seattle?

    Looking for the cheapest flight from London Heathrow Airport to Seattle? While on average our users pay C$ 1,250, our data indicates the cheapest price to be C$ 830. The most popular route (London Heathrow - Seattle/Tacoma Intl), is priced around C$ 1,408.

  • Can I find deals for flights from Heathrow to Seattle that include hotel bookings?

    Yes. In addition to deals on Heathrow to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Heathrow to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Heathrow to Seattle.

  • Can I find deals for business class flights from Heathrow to Seattle?

    Yes. Cheapflights offers flight deals from Heathrow to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from London Heathrow Airport to Seattle?

    Currently, January is the cheapest month in which you can book a flight from London Heathrow Airport to Seattle (average of C$ 687). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of C$ 923). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Travelling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Leavenworth
SeaTac
Mukilteo
Tacoma
Kent
Bothell
Cashmere
Tukwila
Olympia
Renton
Marysville
Lynnwood
Kirkland

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Deals for Heathrow to Seattle flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Heathrow to Seattle?

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Heathrow to Seattle for you. Better yet — we are completely free to use.

Can Cheapflights find flights from Heathrow to Seattle with no change fees?

Yes, we can. To see specific flights from Heathrow to Seattle with no change fees, users can toggle flexible booking options after using the search form above to find flights.

Can Cheapflights notify me if prices for flights from Heathrow to Seattle become cheaper?

Yes, Cheapflights has a feature called Price Alert, which notifies users when flight prices change. Track prices for your flight to Seattle from Heathrow today and book when prices fit your budget.

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