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.
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 |
Find flight deals from Heathrow to Seattle
Cheapest flights from Heathrow to SeattleExplore 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.
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.
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
Fly to
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
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
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
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
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
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
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
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
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
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
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.
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
Crew
Overall
Entertainment
Food
Comfort
Reviews
Kim,May 2025
PIH - SLC
Boarding
Crew
Overall
Entertainment
Food
Comfort
Reviews
Kim,May 2025
PIH - SLC
Boarding
Crew
Overall
Entertainment
Food
Comfort
Reviews
Kim,May 2025
PIH - SLC
Boarding
Crew
Overall
Entertainment
Food
Comfort
Reviews
Kim,May 2025
PIH - SLC
Boarding
Crew
Overall
Entertainment
Food
Comfort
Reviews
Kim,May 2025
PIH - SLC
Boarding
Crew
Overall
Entertainment
Food
Comfort
Reviews
Kim,May 2025
PIH - SLC
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.
Travelling to a place near London Heathrow Airport?
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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.
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.