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Cheap flights from London Heathrow Airport to Seattle from C$ 832

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 25/10. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
3 Aug — 10 Aug1
1 adult

Cheapflights Tip: The best prices from London Heathrow to Seattle/Tacoma Intl are usually found in February or November, booked 62 days in advance, depart on a Tuesday or Friday 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 29 July 2025.

Round-trip from

C$ 905

One-way from

C$ 832

Popular in

July

Cheapest in

February

Average price

C$ 1,380

Good round-trip deal

C$ 1,234 or less
Icelandair
  • Icelandair
  • 14/8-17/8
  • 2 total stops
  • 50h 25m total
  • London to Seattle
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WestJet
  • WestJet
  • 25/10
  • 2 total stops
  • 28h 13m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 14% potential increase in price (C$ 241 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 41 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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Price to beat on a round-trip flight from London Heathrow to Seattle/Tacoma Intl.
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Find flight deals from Heathrow to Seattle

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 29 July 2025.

Thu 14/89:25 p.m.LHR - SEA
1 stop22h 00mIcelandair
Sun 17/811:30 p.m.SEA - LHR
1 stop28h 25mIcelandair
Deal found 27/7C$ 905
Wed 1/107:25 a.m.LHR - SEA
1 stop17h 34mUnited Airlines
Sat 1/115:50 a.m.SEA - LHR
1 stop23h 00mUnited Airlines
Deal found 29/7C$ 908
Mon 20/108:05 p.m.LHR - SEA
2 stops30h 31mSWISS
Mon 10/112:30 p.m.SEA - LHR
2 stops19h 20mSWISS
Deal found 28/7C$ 909
Wed 26/111:25 p.m.LHR - SEA
2 stops28h 06mAir Canada
Sun 30/115:50 a.m.SEA - LHR
2 stops17h 20mAir Canada
Deal found 27/7C$ 913
Tue 28/109:05 a.m.LHR - SEA
2 stops44h 40mAustrian Airlines
Thu 6/118:00 a.m.SEA - LHR
1 stop14h 40mAustrian Airlines
Deal found 29/7C$ 916
Fri 24/106:30 a.m.LHR - SEA
1 stop13h 25mLufthansa
Mon 3/112:00 p.m.SEA - LHR
1 stop16h 50mLufthansa
Deal found 29/7C$ 923
Mon 1/99:50 a.m.LHR - SEA
Nonstop9h 45mBritish Airways
Tue 16/91:30 p.m.SEA - LHR
Nonstop9h 20mBritish Airways
Deal found 27/7C$ 934
Wed 10/95:25 p.m.LHR - SEA
Nonstop10h 25mDelta
Thu 18/98:25 p.m.SEA - LHR
Nonstop9h 50mDelta
Deal found 28/7C$ 944
Wed 10/94:30 p.m.LHR - SEA
Nonstop9h 50mMultiple Airlines
Wed 17/91:39 p.m.SEA - LHR
1 stop14h 36mMultiple Airlines
Deal found 27/7C$ 949
Wed 10/99:50 a.m.LHR - SEA
Nonstop9h 45mFinnair
Mon 15/97:48 a.m.SEA - LHR
1 stop14h 37mFinnair
Deal found 28/7C$ 951

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 29 July 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

Thu 14/8

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

1 stop22h 00m

Seattle/Tacoma Intl

Sun 17/8

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

1 stop28h 25m

C$ 905

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 1/10

7:25 a.m.-4:59 p.m.

1 stop17h 34m

Seattle/Tacoma Intl

Wed 29/10

8:00 p.m.-11:50 a.m.

1 stop32h 50m

C$ 908

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 20/10

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

2 stops30h 31m

Seattle/Tacoma Intl

Mon 10/11

2:30 p.m.-5:50 p.m.

2 stops19h 20m

C$ 909

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 25/10

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

1 stop13h 25m

Seattle/Tacoma Intl

Sat 8/11

10:53 a.m.-7:55 a.m.

1 stop13h 02m

C$ 912

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 26/11

1:25 p.m.-9:31 a.m.

2 stops28h 06m

Seattle/Tacoma Intl

Sun 30/11

5:50 a.m.-7:10 a.m.

2 stops17h 20m

C$ 913

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 28/10

9:05 a.m.-10:45 p.m.

2 stops44h 40m

Seattle/Tacoma Intl

Sun 2/11

8:00 a.m.-5:55 a.m.

2 stops37h 55m

C$ 916

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 1/9

9:50 a.m.-11:35 a.m.

Nonstop9h 45m

Seattle/Tacoma Intl

Tue 16/9

1:30 p.m.-6:50 a.m.

Nonstop9h 20m

C$ 934

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 10/9

5:25 p.m.-7:50 p.m.

Nonstop10h 25m

Seattle/Tacoma Intl

Thu 18/9

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

Nonstop9h 50m

C$ 944

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 10/9

4:30 p.m.-6:20 p.m.

Nonstop9h 50m

Seattle/Tacoma Intl

Wed 17/9

1:39 p.m.-12:15 p.m.

1 stop14h 36m

C$ 949

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 10/9

9:50 a.m.-11:35 a.m.

Nonstop9h 45m

Seattle/Tacoma Intl

Mon 15/9

7:48 a.m.-6:25 a.m.

1 stop14h 37m

C$ 951

Flights are sorted by cheapest round-trip flights first.

Deals found on 29/7

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 25 July 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$ 262). Flying from London Heathrow Airport to Seattle in December is currently the most expensive (average of C$ 353). 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 29 July 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 at noon, which can drop the price by up to 35% versus a flight in the morning.

Weekly flight availability from London Heathrow Airport to Seattle

Explore weekly flight availability from Heathrow to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 29 July 2025.

The most flights from LHR to SEA are scheduled on a Monday (22 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (11 on average).

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

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated 29 July 2025.
See what other customers who have flown with Delta,Austrian Airlines, andFinnair from London Heathrow Airport to Seattle have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,979 reviews
Check prices

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
Delta
8.0
Very good
7,979 reviews
Delta
8.0
Very good
7,979 reviews
Check prices

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
Austrian Airlines
7.6
Good
821 reviews
Delta
8.0
Very good
7,979 reviews
Check prices

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
Finnair
7.6
Good
1,316 reviews
Delta
8.0
Very good
7,979 reviews
Check prices

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
SWISS
7.5
Good
1,683 reviews
Delta
8.0
Very good
7,979 reviews
Check prices

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
United Airlines
7.4
Good
8,896 reviews
Delta
8.0
Very good
7,979 reviews
Check prices

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.

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 19 inbound flights from London Heathrow per day.

  • What are the cheapest airlines flying from London Heathrow Airport to Seattle round-trip?

    Currently priced at C$ 905, Icelandair will fly you from London Heathrow Airport to Seattle and back. In addition to Icelandair, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from United Airlines and SWISS - these airlines can fly you to your destination from C$ 908 and C$ 909, respectively. These flights start at 15% lower than the current average price 3 months from now.

  • What are the cheapest airlines to fly from London Heathrow Airport to Seattle one-way?

    The cheapest airlines for a one-way flight from London Heathrow Airport to Seattle are WestJet (C$ 832), Icelandair (C$ 907), and JetBlue (C$ 1,037).

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

    Consider Scandinavian Airlines (97%), KLM (94%) or Air France (94%) 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$ 1,234, our data indicates the cheapest price to be C$ 1,234. The most popular route (London Heathrow - Seattle/Tacoma Intl), is priced around C$ 1,256.

  • 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$ 262). Flying from London Heathrow Airport to Seattle in December is currently the most expensive (average of C$ 353). 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
Marysville
Bothell
Renton
Olympia
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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