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Cheap flights from London Heathrow Airport to Seattle from £423

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 21/6. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
9 Jul — 16 Jul1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from London Heathrow to Seattle/Tacoma Intl are usually found in January or February, booked 81 days in advance, depart on a Thursday or Wednesday and return on a Tuesday

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 9 June 2026.

Tue 22/917:45
LHR
-
SEA
Nonstop10h 25m
Delta
Thu 4/316:45
SEA
-
LHR
Nonstop9h 45m
Delta
Deal found 9/6£519
Mon 7/912:00
LHR
-
SEA
1 stop13h 10m
British Airways
Wed 16/913:30
SEA
-
LHR
Nonstop9h 15m
British Airways
Deal found 9/6£520
Thu 24/906:15
LHR
-
SEA
1 stop13h 00m
Air France
Tue 2/316:45
SEA
-
LHR
Nonstop9h 45m
Air France
Deal found 9/6£521
Wed 22/717:45
LHR
-
SEA
Nonstop10h 18m
Virgin Atlantic
Thu 6/818:40
SEA
-
LHR
1 stop18h 45m
Virgin Atlantic
Deal found 8/6£522
Fri 19/611:25
LHR
-
SEA
2 stops20h 07m
United Airlines
Sun 21/619:54
SEA
-
LHR
1 stop29h 46m
United Airlines
Deal found 9/6£522
Sun 23/811:40
LHR
-
SEA
Nonstop10h 20m
Delta
Sun 30/821:45
SEA
-
LHR
Nonstop9h 50m
Delta
Deal found 8/6£523
Sat 11/717:45
LHR
-
SEA
Nonstop10h 18m
Delta
Sun 27/906:00
SEA
-
LHR
1 stop17h 10m
Delta
Deal found 8/6£524
Fri 10/711:40
LHR
-
SEA
Nonstop10h 20m
Virgin Atlantic
Tue 14/721:50
SEA
-
LHR
Nonstop9h 45m
Virgin Atlantic
Deal found 8/6£525
Thu 20/819:10
LHR
-
SEA
1 stop29h 49m
Lufthansa
Sun 23/819:20
SEA
-
LHR
2 stops32h 30m
Lufthansa
Deal found 8/6£525
Mon 10/817:45
LHR
-
SEA
Nonstop10h 18m
Delta
Fri 28/807:16
SEA
-
LHR
1 stop15h 09m
Delta
Deal found 9/6£526
Mon 27/715:15
LHR
-
SEA
1 stop16h 44m
Delta
Mon 24/818:35
SEA
-
LHR
2 stops17h 35m
Delta
Deal found 9/6£527
Wed 22/709:30
LHR
-
SEA
1 stop18h 06m
United Airlines
Wed 29/705:00
SEA
-
LHR
2 stops18h 15m
United Airlines
Deal found 8/6£528

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 9 June 2026.

Round-trip from

£519

One-way from

£423

Popular in

July

Cheapest in

January

Average price

£650

Good round-trip deal

£599 or less

Good one-way deal

£606 or less
Delta
  • Delta
  • 22/9-4/3
  • Nonstop
  • 20h 10m total
  • London to Seattle
Search Deals
Icelandair
  • Icelandair
  • 21/6
  • 1 total stop
  • 31h 15m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 10% potential increase in price (£53 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (£8 potential savings vs. average return price).
Search Deals
Average for round-trip flights in June 2026
Search Deals
Price to beat on a round-trip flight from London Heathrow to Seattle/Tacoma Intl.
Search Deals
Price to beat on a one-way flight from London Heathrow to Seattle/Tacoma Intl.
Search Deals

Cheapflights Fare Finder

 
Customise 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 858,174 searches. Data last updated 9 June 2026.
Use the filters below to find and compare flights from London Heathrow Airport to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 27/9

18:30-20:53

Nonstop10h 23m

Seattle/Tacoma Intl

Mon 8/3

16:45-10:30

Nonstop9h 45m

£534

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 6/7

17:45-20:03

Nonstop10h 18m

Seattle/Tacoma Intl

Tue 21/7

18:15-12:05

Nonstop9h 50m

£539

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 11/7

17:45-20:03

Nonstop10h 18m

Seattle/Tacoma Intl

Fri 4/12

16:48-10:30

Nonstop9h 42m

£539

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 11/7

17:45-20:03

Nonstop10h 18m

Seattle/Tacoma Intl

Sat 18/7

21:50-15:35

Nonstop9h 45m

£540

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 14/8

11:25-20:43

2 stops17h 18m

Seattle/Tacoma Intl

Mon 24/8

15:54-12:25

1 stop12h 31m

£552

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 23/9

08:15-17:10

1 stop16h 55m

Seattle/Tacoma Intl

Mon 1/3

18:50-12:20

Nonstop9h 30m

£559

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Fri 4/9

17:45-20:10

Nonstop10h 25m

Seattle/Tacoma Intl

Mon 7/9

21:50-15:35

Nonstop9h 45m

£567

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 27/8

09:50-11:35

Nonstop9h 45m

Seattle/Tacoma Intl

Fri 26/2

11:51-12:00

1 stop16h 09m

£571

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 1/9

13:10-20:52

1 stop15h 42m

Seattle/Tacoma Intl

Sat 27/2

13:35-07:10

Nonstop9h 35m

£576

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 4/7

09:30-23:18

3 stops21h 48m

Seattle/Tacoma Intl

Sun 12/7

12:50-09:40

1 stop12h 50m

£579

Flights are sorted by cheapest return flights first.

Deals found on 4/6

Showing 1-10 of 24 resultsSorted by cheapest first
1
2
3

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 return 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?

The best time to book flights from London Heathrow Airport to Seattle is 80 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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 £507). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of £705). 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 9 June 2026.

When flying from London Heathrow Airport to Seattle, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

How much does it cost for a return flight 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 9 June 2026.
See what other customers who have flown with KLM,Virgin Atlantic, andAir France 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.
KLM
7.8
Good
1,527 reviews
Check prices

Entertainment

7.2

Crew

8.4

Comfort

7.7

Boarding

7.8

Food

7.3

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
KLM
7.8
Good
1,527 reviews
KLM
7.8
Good
1,527 reviews
Check prices

Entertainment

7.2

Crew

8.4

Comfort

7.7

Boarding

7.8

Food

7.3

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
Virgin Atlantic
7.5
Good
689 reviews
KLM
7.8
Good
1,527 reviews
Check prices

Entertainment

7.2

Crew

8.4

Comfort

7.7

Boarding

7.8

Food

7.3

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
Air France
7.4
Good
1,598 reviews
KLM
7.8
Good
1,527 reviews
Check prices

Entertainment

7.2

Crew

8.4

Comfort

7.7

Boarding

7.8

Food

7.3

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
Icelandair
7.0
Good
670 reviews
KLM
7.8
Good
1,527 reviews
Check prices

Entertainment

7.2

Crew

8.4

Comfort

7.7

Boarding

7.8

Food

7.3

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
British Airways
6.7
Okay
8,035 reviews
KLM
7.8
Good
1,527 reviews
Check prices

Entertainment

7.2

Crew

8.4

Comfort

7.7

Boarding

7.8

Food

7.3

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful

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?

    If you book a flight to Seattle from London Heathrow, you will be flying to Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 20 flights from London Heathrow to Seattle/Tacoma Intl per day from 14 different airlines.

  • How long is the flight from London Heathrow Airport to Seattle?

    Departing from London Heathrow Airport to Seattle will take you 10h 18m. The distance from London Heathrow Airport to Seattle is about 4783 mi. This flight may include one or multiple stops.

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

    According to our current data, Lufthansa (£336), Icelandair (£343), and Aer Lingus (£420) offers the cheapest pricing from London Heathrow Airport to Seattle. Lufthansa is priced at 43% lower than the current average price of a flight leaving 3 months from now.

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

    The cheapest airline one-way is Alaska Airlines, with whom users have recently found tickets for as low as £284. However, be on the lookout for offers from Icelandair and British Airways, as they are both options that can get you from London Heathrow Airport to Seattle for a low price.

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

    Consider KLM (88%), Air France (88%) or Delta (88%) 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?

    The cheapest flight price from London Heathrow Airport to Seattle is £449. On average you can expect to pay £1,742. The most popular route, (London Heathrow - Seattle/Tacoma Intl), can usually be booked for £377.

  • 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 holiday 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 £507). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of £705). 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
Tacoma
Federal Way
SeaTac

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Fly from Heathrow to Seattle on these airlines

Choose from the following airlines for your flight from Heathrow to Seattle. Flights are based on user searches made on Cheapflights and were last updated on 9 June 2026.
Virgin Atlantic flights from London Heathrow to Seattle/Tacoma Intl
British Airways flights from London Heathrow to Seattle/Tacoma Intl
Finnair flights from London Heathrow to Seattle/Tacoma Intl

Top 10 airlines flying from Heathrow to Seattle

Discover the top 10 airlines that operate flights from Heathrow to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 858,174 searches. Data last updated 9 June 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£336Average£501FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
IcelandairCheapest£343Average£474FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Aer LingusCheapest£420Average£701FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
Virgin AtlanticCheapest£430Average£596FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
KLMCheapest£444Average£638FlexibilityNo cancel feeOn-time75%
Search KLM flights
Air FranceCheapest£453Average£648FlexibilityNo cancel feeOn-time77%
Search Air France flights
DeltaCheapest£466Average£617FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
British AirwaysCheapest£466Average£640FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Air CanadaCheapest£466Average£501FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
United AirlinesCheapest£469Average£687FlexibilityNo cancel feeOn-time69%
Search United Airlines flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

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 helps you find that perfect flight to Seattle from Heathrow by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Heathrow to Seattle with no change fees?

Need flexible booking options for your flight to Seattle from Heathrow? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

Can Cheapflights notify me if prices for flights from Heathrow to Seattle become cheaper?

Yes! Start tracking prices for Heathrow to Seattle flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

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