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Cheap flights from London Heathrow Airport to Seattle from C$ 791

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 22/4. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
30 Mar — 6 Apr1
1 adult

Cheapflights Tip: The best prices from London Heathrow to Seattle/Tacoma Intl are usually found in February or November, booked 54 days in advance, depart on a Friday 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 25 March 2025.

Round-trip from

C$ 829

One-way from

C$ 791

Popular in

July

Cheapest in

February

Average price

C$ 1,089

Good round-trip deal

C$ 1,332 or less
United Airlines
  • United Airlines
  • 2/6-17/6
  • 3 total stops
  • 48h 26m total
  • London to Seattle
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22/4
  • 22/4
  • 2 total stops
  • 44h 48m total
  • London to Seattle
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Highest demand for flights based on searches. 15% potential increase in price (C$ 294 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease (C$ 40 potential savings vs. average RT price).
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Average for round-trip flights in March 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 25 March 2025.

Mon 2/64:15 p.m.LHR - SEA
2 stops29h 46mUnited Airlines
Tue 17/67:20 a.m.SEA - LHR
1 stop18h 40mUnited Airlines
Deal found 24/3C$ 829
Wed 24/96:55 a.m.LHR - SEA
1 stop18h 04mLufthansa
Mon 29/910:00 a.m.SEA - LHR
2 stops16h 00mLufthansa
Deal found 24/3C$ 861
Tue 22/48:50 a.m.LHR - SEA
1 stop16h 09mBritish Airways
Tue 29/41:30 p.m.SEA - LHR
Nonstop9h 20mBritish Airways
Deal found 24/3C$ 895
Mon 21/46:30 a.m.LHR - SEA
1 stop13h 15mDelta
Mon 5/58:20 p.m.SEA - LHR
Nonstop9h 55mDelta
Deal found 25/3C$ 914
Tue 22/46:00 a.m.LHR - SEA
2 stops24h 43mSWISS
Wed 28/512:44 p.m.SEA - LHR
2 stops25h 01mSWISS
Deal found 24/3C$ 933
Wed 8/109:25 p.m.LHR - SEA
1 stop31h 15mIcelandair
Tue 14/103:45 p.m.SEA - LHR
1 stop12h 10mIcelandair
Deal found 24/3C$ 937
Wed 24/96:30 a.m.LHR - SEA
1 stop13h 15mKLM
Thu 2/108:25 p.m.SEA - LHR
Nonstop9h 50mKLM
Deal found 24/3C$ 961
Mon 2/66:40 a.m.LHR - SEA
1 stop15h 10mScandinavian Airlines
Mon 16/64:00 p.m.SEA - LHR
2 stops18h 50mScandinavian Airlines
Deal found 24/3C$ 973
Thu 24/45:25 p.m.LHR - SEA
Nonstop10h 20mVirgin Atlantic
Thu 1/55:35 p.m.SEA - LHR
Nonstop9h 45mVirgin Atlantic
Deal found 25/3C$ 996
Sat 20/94:40 p.m.LHR - SEA
2 stops58h 09mAustrian Airlines
Sat 11/106:31 a.m.SEA - LHR
2 stops20h 09mAustrian Airlines
Deal found 25/3C$ 1,089
Wed 9/49:00 a.m.LHR - SEA
1 stop15h 59mMultiple Airlines
Mon 21/410:50 a.m.SEA - LHR
1 stop13h 30mMultiple Airlines
Deal found 24/3C$ 1,238
Tue 19/89:50 a.m.LHR - SEA
1 stop15h 09mAer Lingus
Tue 26/86:45 p.m.SEA - LHR
1 stop13h 10mAer Lingus
Deal found 24/3C$ 1,259

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 25 March 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

Mon 2/6

4:15 p.m.-2:01 p.m.

2 stops29h 46m

Seattle/Tacoma Intl

Tue 17/6

7:20 a.m.-10:00 a.m.

1 stop18h 40m

C$ 829

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 22/4

8:50 a.m.-4:59 p.m.

1 stop16h 09m

Seattle/Tacoma Intl

Tue 29/4

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

Nonstop9h 20m

C$ 895

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 21/4

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

1 stop13h 15m

Seattle/Tacoma Intl

Mon 5/5

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

Nonstop9h 55m

C$ 914

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 9/4

9:00 a.m.-4:59 p.m.

1 stop15h 59m

Seattle/Tacoma Intl

Thu 1/5

10:00 a.m.-11:50 a.m.

2 stops17h 50m

C$ 928

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 22/4

6:00 a.m.-10:43 p.m.

2 stops24h 43m

Seattle/Tacoma Intl

Wed 28/5

12:44 p.m.-9:45 p.m.

2 stops25h 01m

C$ 933

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 21/9

9:25 p.m.-5:50 p.m.

1 stop28h 25m

Seattle/Tacoma Intl

Sat 11/10

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

1 stop12h 10m

C$ 947

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 2/6

6:40 a.m.-1:50 p.m.

1 stop15h 10m

Seattle/Tacoma Intl

Mon 16/6

4:00 p.m.-6:50 p.m.

2 stops18h 50m

C$ 973

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 8/4

9:55 a.m.-4:00 p.m.

1 stop14h 05m

Seattle/Tacoma Intl

Tue 29/4

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

Nonstop9h 55m

C$ 978

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 24/4

5:25 p.m.-7:45 p.m.

Nonstop10h 20m

Seattle/Tacoma Intl

Thu 1/5

5:35 p.m.-11:20 a.m.

Nonstop9h 45m

C$ 996

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 20/9

4:40 p.m.-6:49 p.m.

2 stops58h 09m

Seattle/Tacoma Intl

Sat 11/10

6:31 a.m.-10:40 a.m.

2 stops20h 09m

C$ 1,089

Flights are sorted by cheapest round-trip flights first.

Deals found on 24/3

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.

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 21 March 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$ 261). 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 25 March 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 11% 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 25 March 2025.

The most flights from LHR to SEA are scheduled on a Friday (21 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (11 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 25 March 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
7,890 reviews
Check prices

Boarding

8.2

Crew

8.5

Comfort

8.0

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
7,890 reviews
Delta
8.0
Very good
7,890 reviews
Check prices

Boarding

8.2

Crew

8.5

Comfort

8.0

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
1,318 reviews
Delta
8.0
Very good
7,890 reviews
Check prices

Boarding

8.2

Crew

8.5

Comfort

8.0

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
1,266 reviews
Delta
8.0
Very good
7,890 reviews
Check prices

Boarding

8.2

Crew

8.5

Comfort

8.0

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
Austrian Airlines
7.5
Good
769 reviews
Delta
8.0
Very good
7,890 reviews
Check prices

Boarding

8.2

Crew

8.5

Comfort

8.0

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
1,569 reviews
Delta
8.0
Very good
7,890 reviews
Check prices

Boarding

8.2

Crew

8.5

Comfort

8.0

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 15 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$ 829, 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 British Airways and Delta - these airlines can fly you to your destination from C$ 895 and C$ 914, respectively. These flights start at 26% 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$ 792), Icelandair (C$ 898), and Iberia (C$ 1,054).

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

    Consider Aeromexico (98%), Singapore Airlines (98%) or KLM (92%) 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$ 1,543, our data indicates the cheapest price to be C$ 1,063. The most popular route (London Heathrow - Seattle/Tacoma Intl), is priced around C$ 1,063.

  • 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$ 261). 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 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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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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