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Cheap flights from London Heathrow Airport to Seattle from £389

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 27/8. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
7 Jul — 14 Jul1
1 adult

Cheapflights Tip: The best prices from London Heathrow to Seattle/Tacoma Intl are usually found in February or November, booked 76 days in advance, depart on a Tuesday or Wednesday 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 2 July 2025.

Round-trip from

£468

One-way from

£389

Popular in

July

Cheapest in

February

Average price

£736

Good round-trip deal

£509 or less

Good one-way deal

£538 or less
Air Canada
  • Air Canada
  • 11/11-17/11
  • 4 total stops
  • 36h 56m total
  • London to Seattle
27/8
  • 27/8
  • 2 total stops
  • 27h 13m total
  • London to Seattle
Highest demand for flights based on searches. 14% potential increase in price (£69 potential increase over avg. return price).
Cheapest flight prices on average. 2% potential price decrease (£12 potential savings vs. average return price).
Average for round-trip flights in July 2025
Price to beat on a round-trip flight from London Heathrow to Seattle/Tacoma Intl.
Price to beat on a one-way flight from London Heathrow to Seattle/Tacoma Intl.

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 2 July 2025.

Tue 11/1107:40LHR - SEA
2 stops19h 36mMultiple Airlines
Mon 17/1105:50SEA - LHR
2 stops17h 20mMultiple Airlines
Deal found 1/7£468
Thu 11/908:40LHR - SEA
2 stops17h 56mAir Canada
Thu 18/912:00SEA - LHR
1 stop14h 00mAir Canada
Deal found 1/7£470
Mon 25/808:40LHR - SEA
1 stop15h 15mKLM
Wed 10/920:25SEA - LHR
Nonstop9h 50mKLM
Deal found 1/7£471
Tue 26/817:00LHR - SEA
1 stop28h 50mScandinavian Airlines
Sun 31/816:00SEA - LHR
2 stops21h 35mScandinavian Airlines
Deal found 30/6£474
Mon 25/817:25LHR - SEA
Nonstop10h 20mAir France
Wed 10/920:25SEA - LHR
Nonstop9h 50mAir France
Deal found 1/7£477
Mon 24/1106:20LHR - SEA
1 stop14h 55mVirgin Atlantic
Thu 4/1217:20SEA - LHR
Nonstop9h 40mVirgin Atlantic
Deal found 1/7£479
Mon 24/1120:05LHR - SEA
2 stops34h 24mSWISS
Thu 4/1213:18SEA - LHR
2 stops24h 22mSWISS
Deal found 1/7£482
Sat 23/821:25LHR - SEA
1 stop22h 00mIcelandair
Wed 10/923:30SEA - LHR
1 stop12h 50mIcelandair
Deal found 30/6£485
Thu 11/1211:10LHR - SEA
2 stops21h 49mUnited Airlines
Tue 16/1207:10SEA - LHR
1 stop19h 05mUnited Airlines
Deal found 30/6£493
Mon 25/808:40LHR - SEA
1 stop15h 15mDelta
Wed 10/920:25SEA - LHR
Nonstop9h 50mDelta
Deal found 30/6£493
Wed 10/1206:00LHR - SEA
2 stops24h 38mAustrian Airlines
Sat 27/1207:00SEA - LHR
1 stop14h 55mAustrian Airlines
Deal found 29/6£494
Sun 24/808:30LHR - SEA
1 stop18h 19mLufthansa
Mon 15/913:55SEA - LHR
1 stop13h 50mLufthansa
Deal found 30/6£496

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 2 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

Tue 11/11

07:40-19:16

2 stops19h 36m

Seattle/Tacoma Intl

Mon 17/11

05:50-07:10

2 stops17h 20m

£468

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 11/9

08:40-18:36

2 stops17h 56m

Seattle/Tacoma Intl

Thu 18/9

12:00-10:00

1 stop14h 00m

£470

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 25/8

08:40-15:55

1 stop15h 15m

Seattle/Tacoma Intl

Wed 10/9

20:25-14:15

Nonstop9h 50m

£471

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Tue 26/8

17:00-13:50

1 stop28h 50m

Seattle/Tacoma Intl

Sun 31/8

16:00-21:35

2 stops21h 35m

£474

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 25/8

17:25-19:45

Nonstop10h 20m

Seattle/Tacoma Intl

Wed 10/9

20:25-14:15

Nonstop9h 50m

£477

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 24/11

06:20-13:15

1 stop14h 55m

Seattle/Tacoma Intl

Thu 4/12

17:20-11:00

Nonstop9h 40m

£479

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 24/11

20:05-22:29

2 stops34h 24m

Seattle/Tacoma Intl

Thu 4/12

13:18-21:40

2 stops24h 22m

£482

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sat 23/8

21:25-11:25

1 stop22h 00m

Seattle/Tacoma Intl

Wed 10/9

23:30-20:20

1 stop12h 50m

£485

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Thu 11/12

11:10-00:59

2 stops21h 49m

Seattle/Tacoma Intl

Tue 16/12

07:10-10:15

1 stop19h 05m

£493

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 25/8

08:40-15:55

1 stop15h 15m

Seattle/Tacoma Intl

Wed 10/9

20:25-14:15

Nonstop9h 50m

£493

Flights are sorted by cheapest return flights first.

Deals found on 30/6

Showing 1-10 of 16 results
1
2

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?

Use this chart to determine the optimal time to book a return flight from Heathrow to Seattle. Price data was last updated on 27 June 2025.

The best time to book flights from London Heathrow Airport to Seattle is 76 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 £622). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of £946). 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 2 July 2025.

It’s typically best to fly out from London Heathrow Airport to Seattle in the evening. Doing so could potentially save you 20% on the flight price compared to flying in the morning, which is usually more expensive.

What is the cheapest day to fly from London Heathrow Airport to Seattle?

Use this chart to determine the cheapest time to fly return from Heathrow to Seattle. Price data was last updated on 29 June 2025.

Travellers seeking maximum savings on their London Heathrow Airport to Seattle flight should consider departing on Monday evenings when fares are most often at their lowest. Sunday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

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 2 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).

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 2 July 2025.
See what other customers who have flown with Delta, KLM, andAustrian Airlines 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.

Boarding

8.2

Crew

8.5

Overall

8.0

Entertainment

7.9

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
8.0
Very Good

Boarding

8.2

Crew

8.5

Overall

8.0

Entertainment

7.9

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Boarding

8.2

Crew

8.5

Overall

8.0

Entertainment

7.9

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Boarding

8.2

Crew

8.5

Overall

8.0

Entertainment

7.9

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Boarding

8.2

Crew

8.5

Overall

8.0

Entertainment

7.9

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Boarding

8.2

Crew

8.5

Overall

8.0

Entertainment

7.9

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

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 19 flights from London Heathrow to Seattle/Tacoma Intl per day from 13 different airlines.

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

    According to our current data, Air Canada (£470), KLM (£471), and Scandinavian Airlines (£474) offers the cheapest pricing from London Heathrow Airport to Seattle. Air Canada is priced at 17% lower than the current average price of a flight leaving 3 months from now.

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

    Consider Aeromexico (97%), KLM (93%) or Air France (93%) 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 £338. On average you can expect to pay £1,992. The most popular route, (London Heathrow - Seattle/Tacoma Intl), can usually be booked for £406.

  • 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 £622). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of £946). 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
Tacoma
Leavenworth
Bothell
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 2 July 2025.

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 2 July 2025.
AirlineCheapestAverageFlexibilityOn-time
Aer LingusCheapest£7Average£648FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
IcelandairCheapest£347Average£469FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Air FranceCheapest£376Average£551FlexibilityNo cancel feeOn-time77%
Search Air France flights
LufthansaCheapest£382Average£477FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
United AirlinesCheapest£383Average£506FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
FinnairCheapest£394Average£549FlexibilityNo cancel feeOn-time76%
Search Finnair flights
KLMCheapest£397Average£560FlexibilityNo cancel feeOn-time75%
Search KLM flights
Air CanadaCheapest£411Average£572FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
British AirwaysCheapest£415Average£572FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£432Average£570FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic 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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