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Cheap flights from London Heathrow Airport to Seattle from C$ 781

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 31/1. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
29 Nov — 6 Dec1
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 September, booked 76 days in advance, depart on a Monday or Tuesday and return on a Sunday

Cheap 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 30 October 2025.

Round-trip from

C$ 874

One-way from

C$ 781

Popular in

December

Cheapest in

February

Average price

C$ 1,063
Icelandair
  • Icelandair
  • 19/3-30/3
  • 2 total stops
  • 24h 55m total
  • London to Seattle
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British Airways
  • British Airways
  • 31/1
  • Nonstop
  • 10h 00m total
  • London to Seattle
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Highest demand for flights based on searches. 2% potential increase in price (C$ 39 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 36 potential savings vs. average RT price).
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Average for round-trip flights in October 2025
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Find 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 30 October 2025.

Tue 16/128:35 p.m.LHR - SEA
1 stop28h 25mIcelandair
Thu 15/12:35 p.m.SEA - LHR
1 stop12h 15mIcelandair
Deal found 30/10C$ 892
Tue 16/1211:55 a.m.LHR - SEA
1 stop17h 18mBritish Airways
Thu 15/16:50 p.m.SEA - LHR
Nonstop9h 30mBritish Airways
Deal found 30/10C$ 920
Thu 30/1010:15 a.m.LHR - SEA
1 stop19h 01mBritish Airways
Tue 4/111:35 p.m.SEA - LHR
1 stop34h 40mBritish Airways
Deal found 30/10C$ 927
Thu 27/1112:15 p.m.LHR - SEA
1 stop12h 45mIcelandair
Mon 1/122:35 p.m.SEA - LHR
1 stop12h 15mIcelandair
Deal found 30/10C$ 929
Tue 16/1210:05 a.m.LHR - SEA
1 stop16h 50mFinnair
Wed 14/16:50 p.m.SEA - LHR
Nonstop9h 30mFinnair
Deal found 30/10C$ 931
Wed 26/117:30 a.m.LHR - SEA
2 stops18h 40mUnited Airlines
Wed 3/1210:40 a.m.SEA - LHR
1 stop13h 15mUnited Airlines
Deal found 29/10C$ 933
Thu 27/1111:45 a.m.LHR - SEA
1 stop32h 00mVirgin Atlantic
Mon 1/127:20 p.m.SEA - LHR
Nonstop9h 30mVirgin Atlantic
Deal found 30/10C$ 970
Tue 9/126:30 a.m.LHR - SEA
1 stop13h 40mUnited Airlines
Tue 16/128:10 a.m.SEA - LHR
1 stop19h 10mUnited Airlines
Deal found 29/10C$ 973
Thu 27/116:30 a.m.LHR - SEA
2 stops20h 10mDelta
Mon 1/127:15 a.m.SEA - LHR
1 stop16h 35mDelta
Deal found 30/10C$ 977
Thu 25/122:55 p.m.LHR - SEA
Nonstop10h 00mFinnair
Wed 7/16:50 p.m.SEA - LHR
Nonstop9h 30mFinnair
Deal found 30/10C$ 979

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 30 October 2025.
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

Sun 22/3

8:40 a.m.-12:35 p.m.

1 stop34h 55m

Seattle/Tacoma Intl

Mon 30/3

8:25 p.m.-2:15 p.m.

Nonstop9h 50m

C$ 899

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 25/2

11:45 a.m.-11:40 a.m.

1 stop31h 55m

Seattle/Tacoma Intl

Wed 4/3

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

Nonstop9h 45m

C$ 912

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 26/2

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

1 stop13h 10m

Seattle/Tacoma Intl

Mon 9/3

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

Nonstop9h 50m

C$ 912

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 25/2

11:45 a.m.-11:40 a.m.

1 stop31h 55m

Seattle/Tacoma Intl

Tue 10/3

8:20 p.m.-12:50 p.m.

Nonstop9h 30m

C$ 912

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 25/2

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

1 stop13h 10m

Seattle/Tacoma Intl

Thu 5/3

7:20 p.m.-12:50 p.m.

Nonstop9h 30m

C$ 912

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 26/2

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$ 923

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 25/2

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

1 stop13h 10m

Seattle/Tacoma Intl

Fri 6/3

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

Nonstop9h 45m

C$ 924

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 27/11

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

1 stop12h 45m

Seattle/Tacoma Intl

Mon 1/12

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

1 stop12h 15m

C$ 929

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 11/2

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

Nonstop10h 00m

Seattle/Tacoma Intl

Mon 23/2

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

Nonstop9h 30m

C$ 930

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 22/2

12:20 p.m.-2:45 p.m.

Nonstop10h 25m

Seattle/Tacoma Intl

Mon 9/3

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

Nonstop9h 50m

C$ 937

Flights are sorted by cheapest round-trip flights first.

Deals found on 29/10

Showing 1-10 of 21 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 24 October 2025.

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 76 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$ 666). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of C$ 940). 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 30 October 2025.

When flying from London Heathrow Airport to Seattle, the time of day you fly usually plays a role in the price. Save by searching for a flight in the afternoon, which can drop the price by up to 27% versus a flight in the evening.

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 5 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 10h. Delta provides one of the quickest options available for as low as C$ 930. 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 Scandinavian Airlines (95%), KLM (87%) or Air France (87%) when booking your flight. These represent the most reliable airlines when flying from London Heathrow Airport to Seattle.

  • 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$ 666). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of C$ 940). 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
Tukwila
Tacoma
Mukilteo
Bothell
Cashmere
Olympia
Renton
Marysville
Lynnwood

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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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