Cheap flights from London Heathrow Airport to Seattle from £400
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 23/9. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SEA
3 Sep — 10 Sep1
Return
1 adult
Economy
Return
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 57 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.
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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 4 August 2026.
Mon 31/809:50 -
Nonstop9h 45m
Fri 18/913:30 -
Nonstop9h 15m
Deal found 3/8£450
Mon 12/1021:25 -
1 stop28h 30m
Mon 19/1019:00 -
1 stop17h 20m
Deal found 30/7£452
Sun 25/1013:35 -
1 stop29h 44m
Tue 27/1010:40 -
1 stop13h 45m
Deal found 1/8£453
Wed 26/813:05 -
1 stop15h 35m
Fri 18/915:40 -
1 stop12h 15m
Deal found 3/8£454
Tue 6/1021:25 -
1 stop28h 30m
Mon 12/1015:40 -
1 stop12h 15m
Deal found 30/7£457
Tue 6/1013:05 -
1 stop15h 35m
Mon 19/1015:40 -
1 stop12h 15m
Deal found 31/7£459
Sun 1/1120:35 -
1 stop28h 25m
Tue 10/1108:18 -
2 stops15h 47m
Deal found 3/8£461
Tue 25/809:50 -
Nonstop9h 45m
Wed 16/913:30 -
Nonstop9h 15m
Deal found 3/8£462
Sat 10/1021:25 -
1 stop28h 30m
Tue 10/1108:18 -
2 stops15h 47m
Deal found 30/7£462
Wed 26/809:50 -
Nonstop9h 45m
Sat 19/920:20 -
Nonstop9h 25m
Deal found 3/8£463
Fri 2/1013:05 -
1 stop15h 35m
Mon 5/1015:40 -
1 stop20h 40m
Deal found 1/8£467
Tue 25/811:05 -
1 stop16h 02m
Sat 19/915:54 -
1 stop12h 31m
Deal found 3/8£468
Best flights from Heathrow to Seattle
Discover carefully curated flight deals from Heathrow to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 4 August 2026.
Wed 16/910:50 -
1 stop14h 09m
Fri 25/909:05 -
2 stops16h 35m
Deal found 30/7£525
Fri 28/811:40 -
Nonstop10h 20m
Sat 12/921:50 -
Nonstop9h 45m
Deal found 30/7£563
Fri 11/914:25 -
1 stop15h 11m
Tue 22/914:12 -
1 stop14h 38m
Deal found 31/7£574
Tue 1/907:25 -
2 stops19h 42m
Tue 8/915:30 -
1 stop14h 40m
Deal found 3/8£534
Tue 1/911:40 -
Nonstop10h 20m
Tue 8/917:30 -
Nonstop9h 50m
Deal found 3/8£569
Thu 17/907:25 -
2 stops19h 49m
Thu 24/908:30 -
2 stops17h 55m
Deal found 3/8£535
Fri 4/917:45 -
Nonstop10h 25m
Sat 19/921:50 -
Nonstop9h 45m
Deal found 3/8£571
Fri 18/919:30 -
1 stop26h 15m
Sat 10/1015:55 -
2 stops17h 05m
Deal found 3/8£1,319
Thu 20/816:30 -
Nonstop9h 55m
Mon 24/810:19 -
1 stop13h 46m
Deal found 2/8£679
Sun 13/918:30 -
Nonstop10h 23m
Sat 19/922:40 -
1 stop13h 30m
Deal found 1/8£584
Fri 14/807:25 -
1 stop17h 34m
Mon 24/811:03 -
2 stops16h 52m
Deal found 3/8£831
Direct flights from Heathrow to Seattle
Explore direct flight options from Heathrow to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 4 August 2026.
Mon 31/809:50 -
Nonstop9h 45m
Fri 18/913:30 -
Nonstop9h 15m
Deal found 3/8£450
Tue 25/809:50 -
Nonstop9h 45m
Wed 16/913:30 -
Nonstop9h 15m
Deal found 3/8£462
Wed 26/809:50 -
Nonstop9h 45m
Sat 19/920:20 -
Nonstop9h 25m
Deal found 3/8£463
Fri 2/1011:40 -
Nonstop10h 20m
Mon 5/1021:50 -
Nonstop9h 45m
Deal found 1/8£471
Sat 29/809:50 -
Nonstop9h 45m
Wed 16/920:20 -
Nonstop9h 25m
Deal found 3/8£477
Sat 19/909:50 -
Nonstop9h 45m
Sat 26/913:30 -
Nonstop9h 15m
Deal found 1/8£484
Wed 23/1212:20 -
Nonstop10h 34m
Wed 6/116:55 -
Nonstop9h 45m
Deal found 3/8£487
Tue 8/916:30 -
Nonstop9h 55m
Sat 26/920:20 -
Nonstop9h 25m
Deal found 3/8£488
Fri 11/917:00 -
Nonstop10h 00m
Sat 26/921:40 -
Nonstop9h 25m
Deal found 31/7£508
Sun 20/1212:20 -
Nonstop10h 34m
Fri 1/116:55 -
Nonstop9h 45m
Deal found 31/7£509
Sun 30/809:50 -
Nonstop9h 45m
Tue 15/913:30 -
Nonstop9h 15m
Deal found 3/8£511
Sun 30/809:50 -
Nonstop9h 45m
Thu 17/920:20 -
Nonstop9h 25m
Deal found 3/8£512
Last-minute flights from Heathrow to Seattle
Discover last-minute flight deals from Heathrow to Seattle. Data last updated 4 August 2026 and is based on user searches.
Mon 24/821:25 -
1 stop22h 20m
Mon 7/923:25 -
1 stop12h 55m
Deal found 2/8£474
Tue 25/809:50 -
Nonstop9h 45m
Wed 16/913:30 -
Nonstop9h 15m
Deal found 3/8£462
Tue 25/811:05 -
1 stop16h 02m
Sat 19/915:54 -
1 stop12h 31m
Deal found 3/8£468
Wed 26/813:05 -
1 stop15h 35m
Fri 18/915:40 -
1 stop12h 15m
Deal found 3/8£454
Wed 26/809:50 -
Nonstop9h 45m
Sat 19/920:20 -
Nonstop9h 25m
Deal found 3/8£463
Mon 31/809:50 -
Nonstop9h 45m
Fri 18/913:30 -
Nonstop9h 15m
Deal found 3/8£450
Mon 31/821:25 -
1 stop22h 20m
Mon 7/919:00 -
1 stop17h 20m
Deal found 3/8£470
Tue 1/921:25 -
1 stop22h 20m
Wed 30/919:00 -
1 stop17h 20m
Deal found 4/8£475
Wed 2/913:05 -
1 stop12h 50m
Wed 16/919:00 -
1 stop17h 20m
Deal found 30/7£473
Wed 2/913:05 -
1 stop15h 35m
Mon 7/915:40 -
1 stop12h 15m
Deal found 1/8£476
Sun 6/921:25 -
1 stop22h 20m
Wed 30/915:40 -
1 stop12h 15m
Deal found 31/7£474
Wed 9/913:05 -
1 stop12h 50m
Wed 16/915:40 -
1 stop12h 15m
Deal found 1/8£472
One-way flights from Heathrow to Seattle
Search for one-way flight options from Heathrow to Seattle. Find affordable one-way fares based on user searches. Data last updated 4 August 2026.
Wed 23/917:00 -
Nonstop10h 00m
Deal found 3/8£400
Mon 14/912:40 -
2 stops42h 07m
Deal found 3/8£401
Sun 30/820:50 -
3 stops53h 01m
Deal found 3/8£402
Tue 29/907:45 -
3 stops23h 41m
Deal found 31/7£403
Sat 19/906:55 -
1 stop18h 04m
Deal found 3/8£404
Wed 30/907:45 -
3 stops23h 41m
Deal found 3/8£404
Sat 12/907:25 -
1 stop17h 34m
Deal found 3/8£405
Fri 18/911:55 -
1 stop16h 49m
Deal found 1/8£406
Wed 9/920:50 -
3 stops44h 50m
Deal found 31/7£407
Thu 10/908:40 -
1 stop21h 57m
Deal found 1/8£407
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 4 August 2026.
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 4 August 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
Wed 16/9
10:50-16:59
1 stop14h 09m
Seattle/Tacoma Intl
Fri 25/9
09:05-09:40
2 stops16h 35m
£525
LondonSeattle
LHR - SEA
LHRSEA
London Heathrow
Tue 1/9
07:25-19:07
2 stops19h 42m
Seattle/Tacoma Intl
Tue 8/9
15:30-14:10
1 stop14h 40m
£534
LondonSeattle
LHR - SEA
LHRSEA
London Heathrow
Thu 17/9
07:25-19:14
2 stops19h 49m
Seattle/Tacoma Intl
Thu 24/9
08:30-10:25
2 stops17h 55m
£535
Fastest return journey
LondonSeattle
LHR - SEA
LHRSEA
London Heathrow
Fri 28/8
11:40-14:00
Nonstop10h 20m
Seattle/Tacoma Intl
Sat 12/9
21:50-15:35
Nonstop9h 45m
£563
LondonSeattle
LHR - SEA
LHRSEA
London Heathrow
Tue 1/9
11:40-14:00
Nonstop10h 20m
Seattle/Tacoma Intl
Tue 8/9
17:30-11:20
Nonstop9h 50m
£569
LondonSeattle
LHR - SEA
LHRSEA
London Heathrow
Fri 4/9
17:45-20:10
Nonstop10h 25m
Seattle/Tacoma Intl
Sat 19/9
21:50-15:35
Nonstop9h 45m
£571
LondonSeattle
LHR - SEA
LHRSEA
London Heathrow
Fri 11/9
14:25-21:36
1 stop15h 11m
Seattle/Tacoma Intl
Tue 22/9
14:12-12:50
1 stop14h 38m
£574
LondonSeattle
LHR - SEA
LHRSEA
London Heathrow
Sun 13/9
18:30-20:53
Nonstop10h 23m
Seattle/Tacoma Intl
Sat 19/9
22:40-20:10
1 stop13h 30m
£584
LondonSeattle
LHR - SEA
LHRSEA
London Heathrow
Thu 20/8
16:30-18:25
Nonstop9h 55m
Seattle/Tacoma Intl
Mon 24/8
10:19-08:05
1 stop13h 46m
£679
LondonSeattle
LHR - SEA
LHRSEA
London Heathrow
Fri 14/8
07:25-16:59
1 stop17h 34m
Seattle/Tacoma Intl
Mon 24/8
11:03-11:55
2 stops16h 52m
£831
Flights are sorted by cheapest return flights first.
Deals found on 4/8
Showing 1-10 of 22 resultsSorted by cheapest first
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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.
LHR-SEA
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
Prices
Airlines
Delays
More
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 56 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 £494). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of £665). 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 4 August 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?
Airfare is below average for this route at the moment.
London Heathrow Airport to Seattle flights typically cost between £528 and £694 in August.The cheapest return price found within the last 5 days was £450 on British Airways (31 Aug–18 Sept).
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 4 August 2026.
The most flights from LHR to SEA are scheduled on a Monday (24 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (17 on average).
How often are flights from London to Seattle delayed?
About 11% of weekly flights between London and Seattle have experienced delays in the past year, with the average delay time being 128 minutes.
What is the most punctual flight time for London to Seattle flights?
Historically, flights departing in the evening are less likely to be delayed, whereas flights leaving in the early afternoon tend to experience delays more often.
What day of the week experiences the fewest flight delays on this route?
Thursday tends to have the lowest number of delays on this route, whereas Tuesday has historically faced a higher average of delays compared to other days of the week.
Which airline has the best punctuality record on London to Seattle flights?
Over the past year, Delta have had the lowest number of delays on this route, with just 5% of flights being delayed.
What’s the top stopover airport for flights from London Heathrow Airport to Seattle?
Share of one-stop return flights from London Heathrow Airport to Seattle chosen by Cheapflights users in the past 12 months, using the same stopover each way.
Reykjavik (KEF) – chosen by Cheapflights users on 82% of one-stop itineraries from London Heathrow Airport to Seattle on Cheapflights.
What’s the cheapest stopover airport for flights from London Heathrow Airport to Seattle?
Average return fare for one-stop flights from London Heathrow Airport to Seattle, chosen by Cheapflights users in the past 12 months, with the same stopover each way.
Dallas (DFW) is the most affordable one-stop option, with an average return flight price of £493.
What’s the fastest stopover option from London Heathrow Airport to Seattle?
Shortest average travel time for one-stop one-way flights from London Heathrow Airport to Seattle, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by stopover airport.
Flights via Vancouver (YVR) have the shortest average one-way travel time for one-stop routes: 12h 46m.
Which airport typically offers the quickest stopover for flights from London Heathrow Airport to Seattle?
Average stopover duration for one-stop one-way flights from London Heathrow Airport to Seattle, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.
Flights via Denver (DEN) offer the fastest connection on this route, with an average stopover time of 1h 23m.
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 4 August 2026.
See what other customers who have flown with Alaska Airlines,KLM, andVirgin Atlantic 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.
It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
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 21 flights from London Heathrow to Seattle/Tacoma Intl per day from 13 different airlines.
How long is the flight from London Heathrow Airport to Seattle?
Departing from London Heathrow Airport to Seattle will take you 10h 20m. 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 (£334), Icelandair (£340), and Aer Lingus (£390) 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 Icelandair, with whom users have recently found tickets for as low as £352. However, be on the lookout for offers from British Airways and Virgin Atlantic, 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 Scandinavian Airlines (85%), KLM (77%) or Air France (77%) 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 £379. On average you can expect to pay £1,819. The most popular route, (London Heathrow - Seattle/Tacoma Intl), can usually be booked for £412.
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 £494). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of £665). 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.
Book flights to Seattle if you plan to visit one of these locations
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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 4 August 2026.
Explore flights to Seattle departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on 4 August 2026.
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 4 August 2026.
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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