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Cheap flights from London Heathrow Airport to Seattle from C$ 692

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 10/3. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
25 Feb — 4 Mar1
1 adult

The best prices from London Heathrow to Seattle/Tacoma Intl are usually found in November or January, booked 54 days in advance, depart on a Friday or Tuesday and return on a Tuesday

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 20 February 2025.

Round-trip from

C$ 813

One-way from

C$ 692

Popular in

July

Cheapest in

November

Average price

C$ 990
United Airlines
  • United Airlines
  • 21/3-23/3
  • 3 total stops
  • 34h 05m total
  • London to Seattle
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10/3
  • 10/3
  • 3 total stops
  • 27h 56m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 15% potential increase in price (C$ 282 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 39 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 2025
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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 20 February 2025.

Fri 21/36:30 a.m.LHR - SEA
2 stops22h 00mUnited Airlines
Sun 23/33:05 p.m.SEA - LHR
1 stop12h 05mUnited Airlines
Deal found 19/2C$ 813
Fri 7/36:35 a.m.LHR - SEA
1 stop14h 45mLufthansa
Mon 24/33:05 p.m.SEA - LHR
1 stop12h 05mLufthansa
Deal found 18/2C$ 837
Tue 11/38:55 a.m.LHR - SEA
2 stops20h 58mSWISS
Tue 18/32:50 p.m.SEA - LHR
2 stops21h 25mSWISS
Deal found 19/2C$ 841
Thu 1/51:05 p.m.LHR - SEA
1 stop12h 45mIcelandair
Tue 20/53:45 p.m.SEA - LHR
1 stop12h 10mIcelandair
Deal found 18/2C$ 872
Mon 3/36:30 a.m.LHR - SEA
1 stop13h 07mDelta
Mon 17/36:45 p.m.SEA - LHR
Nonstop9h 25mDelta
Deal found 19/2C$ 881
Tue 22/46:30 a.m.LHR - SEA
1 stop13h 15mKLM
Wed 30/48:20 p.m.SEA - LHR
Nonstop9h 55mKLM
Deal found 19/2C$ 892
Tue 4/310:40 a.m.LHR - SEA
1 stop16h 25mFinnair
Tue 11/37:50 p.m.SEA - LHR
Nonstop9h 25mFinnair
Deal found 18/2C$ 901
Sat 1/39:25 a.m.LHR - SEA
Nonstop9h 55mBritish Airways
Tue 4/31:33 p.m.SEA - LHR
1 stop12h 27mBritish Airways
Deal found 19/2C$ 955
Wed 26/116:20 a.m.LHR - SEA
1 stop13h 50mVirgin Atlantic
Sun 30/113:25 p.m.SEA - LHR
Nonstop9h 55mVirgin Atlantic
Deal found 19/2C$ 1,026
Thu 22/57:50 p.m.LHR - SEA
2 stops26h 00mScandinavian Airlines
Sat 31/54:00 p.m.SEA - LHR
1 stop16h 00mScandinavian Airlines
Deal found 19/2C$ 1,154

Find flights from Heathrow to Seattle within your budget

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 20 February 2025.

Fly from

Heathrow

Fly to

Seattle

Route

Depart

Return

Price

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 21/3

6:30 a.m.-9:30 p.m.

2 stops22h 00m

Seattle/Tacoma Intl

Sun 23/3

3:05 p.m.-10:10 a.m.

1 stop12h 05m

C$ 813

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 7/3

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

1 stop14h 45m

Seattle/Tacoma Intl

Mon 24/3

3:05 p.m.-10:10 a.m.

1 stop12h 05m

C$ 837

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 11/3

8:55 a.m.-10:53 p.m.

2 stops20h 58m

Seattle/Tacoma Intl

Tue 18/3

2:50 p.m.-7:15 p.m.

2 stops21h 25m

C$ 841

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 1/5

1:05 p.m.-5:50 p.m.

1 stop12h 45m

Seattle/Tacoma Intl

Tue 20/5

3:45 p.m.-11:55 a.m.

1 stop12h 10m

C$ 872

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 3/3

6:30 a.m.-11:37 a.m.

1 stop13h 07m

Seattle/Tacoma Intl

Mon 17/3

6:45 p.m.-11:10 a.m.

Nonstop9h 25m

C$ 881

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 22/4

6:30 a.m.-11:45 a.m.

1 stop13h 15m

Seattle/Tacoma Intl

Wed 30/4

8:20 p.m.-2:15 p.m.

Nonstop9h 55m

C$ 892

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 4/3

10:40 a.m.-7:05 p.m.

1 stop16h 25m

Seattle/Tacoma Intl

Tue 11/3

7:50 p.m.-12:15 p.m.

Nonstop9h 25m

C$ 901

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 1/3

9:25 a.m.-11:20 a.m.

Nonstop9h 55m

Seattle/Tacoma Intl

Tue 4/3

1:33 p.m.-10:00 a.m.

1 stop12h 27m

C$ 955

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 22/5

7:50 p.m.-1:50 p.m.

2 stops26h 00m

Seattle/Tacoma Intl

Sat 31/5

4:00 p.m.-4:00 p.m.

1 stop16h 00m

C$ 1,154

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 26/3

10:40 a.m.-7:15 p.m.

1 stop15h 35m

Seattle/Tacoma Intl

Fri 27/6

6:45 p.m.-2:55 p.m.

1 stop12h 10m

C$ 1,254

Flights are sorted by cheapest round-trip flights first.

Deals found on 19/2

Showing 1-10 of 23 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.

Travel insights for flights from Heathrow to Seattle

Get recent, data-driven insights about flights from Heathrow to Seattle including ideal travel times, pricing trends, and more.

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 14 February 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 54 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 April is currently the most expensive (average of C$ 382). 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 20 February 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 4% 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 20 February 2025.

The most flights from LHR to SEA are scheduled on a Friday (16 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (6 on average).

Rainfall in Seattle by month

Plan your trip to Seattle by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Seattle ranges from 18.0 - 168.0 mm per month. November is typically the wettest month, when rainfall can reach 168.0 mm. July is typically the driest time to visit Seattle when rainfall is around 18.0 mm.

Temperature in Seattle by month

Plan your trip to Seattle by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Seattle, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 19.0 C. Travellers hoping to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 5.0 C).

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 20 February 2025.
See what other customers who have flown with Delta, KLM and Finnair from London to Seattle have to say. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
8,236 reviews
Check prices

Comfort

8.0

Boarding

8.2

Crew

8.5

Entertainment

7.9

Food

7.3

Overall

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Delta
8.0
Very good
8,236 reviews
Delta
8.0
Very good
8,236 reviews
Check prices

Comfort

8.0

Boarding

8.2

Crew

8.5

Entertainment

7.9

Food

7.3

Overall

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

KLM
7.8
Good
1,333 reviews
Delta
8.0
Very good
8,236 reviews
Check prices

Comfort

8.0

Boarding

8.2

Crew

8.5

Entertainment

7.9

Food

7.3

Overall

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Finnair
7.6
Good
1,274 reviews
Delta
8.0
Very good
8,236 reviews
Check prices

Comfort

8.0

Boarding

8.2

Crew

8.5

Entertainment

7.9

Food

7.3

Overall

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

SWISS
7.5
Good
1,568 reviews
Delta
8.0
Very good
8,236 reviews
Check prices

Comfort

8.0

Boarding

8.2

Crew

8.5

Entertainment

7.9

Food

7.3

Overall

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

United Airlines
7.4
Good
8,771 reviews
Delta
8.0
Very good
8,236 reviews
Check prices

Comfort

8.0

Boarding

8.2

Crew

8.5

Entertainment

7.9

Food

7.3

Overall

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

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 11 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$ 813, United Airlines will fly you from London Heathrow Airport to Seattle and back. In addition to United Airlines, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Lufthansa and SWISS - these airlines can fly you to your destination from C$ 837 and C$ 841, respectively. These flights start at 27% 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$ 696), Aer Lingus (C$ 763), and Iberia (C$ 1,014).

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

    Consider Singapore Airlines (97%), KLM (89%) or Air France (89%) 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$ 262). Flying from London Heathrow Airport to Seattle in April is currently the most expensive (average of C$ 382). 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 London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
SeaTac
Tukwila
Marysville
Bothell
Leavenworth
Tacoma
Olympia
Lynnwood

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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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