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Cheap flights from London Heathrow Airport to Seattle from C$ 727

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 13/2. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
15 Jan — 22 Jan1
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 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 16 December 2025.

Tue 16/122:10 p.m.LHR - SEA
1 stop17h 15mBritish Airways
Wed 14/12:09 p.m.SEA - LHR
1 stop14h 06mBritish Airways
Deal found 15/12C$ 1,369
Tue 23/1212:35 p.m.LHR - SEA
1 stop33h 27mBritish Airways
Tue 6/16:52 p.m.SEA - LHR
1 stop35h 08mBritish Airways
Deal found 16/12C$ 1,416
Tue 23/1212:35 p.m.LHR - SEA
1 stop18h 38mBritish Airways
Tue 30/1211:49 a.m.SEA - LHR
1 stop14h 11mBritish Airways
Deal found 15/12C$ 1,489
Wed 24/126:35 a.m.LHR - SEA
1 stop14h 45mUnited Airlines
Sun 28/1211:09 p.m.SEA - LHR
1 stop13h 26mUnited Airlines
Deal found 15/12C$ 1,501
Wed 24/127:40 a.m.LHR - SEA
2 stops18h 26mUnited Airlines
Mon 29/1212:44 p.m.SEA - LHR
1 stop12h 56mUnited Airlines
Deal found 15/12C$ 1,514
Tue 23/124:40 p.m.LHR - SEA
1 stop28h 40mUnited Airlines
Sun 28/1211:09 p.m.SEA - LHR
1 stop13h 26mUnited Airlines
Deal found 15/12C$ 1,515
Wed 24/122:10 p.m.LHR - SEA
1 stop31h 52mBritish Airways
Tue 30/127:07 a.m.SEA - LHR
1 stop17h 28mBritish Airways
Deal found 15/12C$ 1,516
Tue 23/1211:45 a.m.LHR - SEA
1 stop32h 05mDelta
Mon 5/19:20 p.m.SEA - LHR
1 stop29h 20mDelta
Deal found 16/12C$ 1,522
Tue 23/1210:45 a.m.LHR - SEA
2 stops62h 04mBritish Airways
Mon 5/17:23 p.m.SEA - LHR
1 stop32h 37mBritish Airways
Deal found 16/12C$ 1,530
Sun 21/1211:50 a.m.LHR - SEA
1 stop18h 54mFinnair
Tue 30/126:00 a.m.SEA - LHR
1 stop24h 00mFinnair
Deal found 15/12C$ 1,537
Tue 23/122:10 p.m.LHR - SEA
1 stop31h 52mBritish Airways
Sun 28/126:50 p.m.SEA - LHR
Nonstop9h 30mBritish Airways
Deal found 15/12C$ 1,572
Wed 24/128:05 p.m.LHR - SEA
2 stops33h 02mSWISS
Fri 9/112:35 p.m.SEA - LHR
2 stops21h 15mSWISS
Deal found 16/12C$ 1,573

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 16 December 2025.

Round-trip from

C$ 833

One-way from

C$ 727

Popular in

July

Cheapest in

February

Average price

C$ 1,289

Good one-way deal

C$ 964 or less
American Airlines
  • American Airlines
  • 19/4-30/4
  • Nonstop
  • 19h 10m total
  • London to Seattle
Search Deals
Lufthansa
  • Lufthansa
  • 13/2
  • 1 total stop
  • 14h 45m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (C$ 206 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 35 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
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 16 December 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

Tue 10/3

6:00 a.m.-10:45 p.m.

2 stops23h 45m

Seattle/Tacoma Intl

Tue 24/3

10:55 a.m.-1:00 p.m.

2 stops19h 05m

C$ 963

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

Wed 14/1

6:50 a.m.-11:32 a.m.

2 stops36h 42m

Seattle/Tacoma Intl

Thu 1/10

5:07 a.m.-9:35 a.m.

2 stops20h 28m

C$ 1,002

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 14/1

10:05 a.m.-9:47 p.m.

1 stop19h 42m

Seattle/Tacoma Intl

Thu 1/10

1:35 p.m.-6:50 a.m.

Nonstop9h 15m

C$ 1,014

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 13/2

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

1 stop14h 45m

Seattle/Tacoma Intl

Thu 19/2

7:00 a.m.-10:15 a.m.

2 stops19h 15m

C$ 1,017

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 15/1

9:00 a.m.-10:43 p.m.

2 stops21h 43m

Seattle/Tacoma Intl

Thu 22/1

12:35 p.m.-5:50 p.m.

2 stops21h 15m

C$ 1,018

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 15/1

9:00 a.m.-10:43 p.m.

2 stops21h 43m

Seattle/Tacoma Intl

Wed 23/9

2:52 p.m.-5:50 p.m.

2 stops18h 58m

C$ 1,018

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 13/1

4:40 p.m.-1:20 p.m.

1 stop28h 40m

Seattle/Tacoma Intl

Sat 16/5

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

2 stops49h 45m

C$ 1,020

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 29/1

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

1 stop13h 40m

Seattle/Tacoma Intl

Thu 5/2

9:25 a.m.-7:25 a.m.

1 stop14h 00m

C$ 1,020

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 19/3

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

1 stop13h 40m

C$ 728

Flights are sorted by cheapest round-trip flights first.

Deals found on 16/12

Showing 1-10 of 19 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 12 December 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 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$ 669). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of C$ 934). 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 16 December 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 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 40m. SWISS provides one of the quickest options available for as low as C$ 972. 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 (97%), Air France (93%) or Delta (90%) 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$ 965, our data indicates the cheapest price to be C$ 964. The most popular route (London Heathrow - Seattle/Tacoma Intl), is priced around C$ 1,116.

  • 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$ 669). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of C$ 934). 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
Tukwila
Bothell
Cashmere
Olympia
Renton
Marysville
Lynnwood

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How does Cheapflights help users find flights from Heathrow to Seattle?

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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