Cheap flights from Seattle to London Heathrow Airport from £253
This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 21/11. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
27 Oct — 3 Nov1
Return
1 adult
Economy
Return
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London Heathrow are usually found in January or February, booked 35 days in advance, depart on a Wednesday or Monday and return on a Thursday
Cheap flight deals from Seattle to Heathrow
Enter your travel dates to find the best prices.
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Best
Direct
Last-minute
One-way
Cheapest flights from Seattle to Heathrow
Explore the most affordable flight options available from Seattle to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 27 September 2026.
Sun 4/1007:00 -
1 stop15h 45m
Sun 11/1007:25 -
1 stop17h 34m
Deal found 22/9£582
Thu 15/1021:50 -
Nonstop9h 45m
Thu 22/1006:30 -
1 stop18h 05m
Deal found 21/9£583
Sun 8/1110:10 -
1 stop17h 40m
Tue 10/1106:35 -
2 stops19h 47m
Deal found 21/9£584
Thu 1/1018:50 -
1 stop19h 50m
Tue 20/1013:50 -
2 stops36h 42m
Deal found 22/9£584
Tue 13/1021:50 -
Nonstop9h 45m
Tue 20/1006:30 -
1 stop13h 22m
Deal found 23/9£585
Wed 25/1114:35 -
1 stop20h 55m
Tue 1/1212:15 -
1 stop12h 45m
Deal found 25/9£586
Tue 8/1216:50 -
Nonstop9h 50m
Wed 13/106:30 -
1 stop13h 20m
Deal found 23/9£587
Mon 5/1019:15 -
2 stops53h 20m
Mon 12/1010:15 -
2 stops20h 32m
Deal found 22/9£587
Tue 13/1021:40 -
Nonstop9h 25m
Mon 19/1017:00 -
Nonstop10h 00m
Deal found 23/9£588
Mon 14/1205:05 -
1 stop20h 35m
Fri 25/1211:35 -
2 stops17h 05m
Deal found 23/9£589
Fri 30/1010:10 -
2 stops16h 10m
Fri 6/1109:00 -
2 stops22h 20m
Deal found 22/9£590
Tue 20/1010:50 -
1 stop18h 30m
Sun 1/1113:00 -
2 stops28h 32m
Deal found 24/9£590
Best flights from Seattle to Heathrow
Discover carefully curated flight deals from Seattle to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 27 September 2026.
Sat 7/1119:05 -
1 stop32h 45m
Sat 14/1116:40 -
1 stop28h 20m
Deal found 23/9£587
Fri 25/1214:35 -
1 stop12h 15m
Fri 8/120:35 -
1 stop28h 25m
Deal found 25/9£620
Fri 23/1021:50 -
Nonstop9h 45m
Mon 2/1108:55 -
1 stop14h 19m
Deal found 23/9£621
Sun 1/1110:51 -
2 stops21h 09m
Mon 16/1106:40 -
2 stops24h 20m
Deal found 25/9£628
Sat 10/1021:50 -
Nonstop9h 45m
Wed 21/1009:55 -
1 stop14h 40m
Deal found 25/9£792
Thu 4/209:50 -
2 stops22h 10m
Sun 14/218:40 -
2 stops32h 25m
Deal found 26/9£636
Wed 13/116:55 -
Nonstop9h 45m
Thu 28/111:45 -
1 stop32h 05m
Deal found 24/9£651
Mon 9/1115:15 -
1 stop12h 35m
Mon 16/1111:35 -
1 stop14h 22m
Deal found 25/9£746
Mon 16/1116:50 -
Nonstop9h 50m
Sun 22/1108:55 -
1 stop14h 19m
Deal found 25/9£722
Sat 10/1021:50 -
Nonstop9h 45m
Sat 17/1017:45 -
Nonstop10h 29m
Deal found 24/9£852
Sun 11/1011:08 -
1 stop14h 07m
Sun 18/1018:30 -
Nonstop10h 25m
Deal found 26/9£816
Sat 26/1216:50 -
Nonstop9h 50m
Sun 3/112:20 -
Nonstop10h 25m
Deal found 22/9£1,221
Direct flights from Seattle to Heathrow
Explore direct flight options from Seattle to Heathrow based on user searches, and compare prices and availability for your desired travel dates. Data last updated 27 September 2026.
Wed 13/118:45 -
Nonstop9h 25m
Sun 24/114:55 -
Nonstop9h 55m
Deal found 22/9£583
Thu 19/1113:40 -
Nonstop9h 30m
Tue 24/1114:55 -
Nonstop9h 55m
Deal found 23/9£584
Sun 21/319:45 -
Nonstop9h 25m
Sat 3/416:30 -
Nonstop9h 55m
Deal found 23/9£586
Fri 9/1021:50 -
Nonstop9h 45m
Wed 14/1011:40 -
Nonstop10h 20m
Deal found 23/9£588
Wed 13/118:50 -
Nonstop9h 30m
Sun 17/114:45 -
Nonstop9h 55m
Deal found 23/9£591
Thu 4/218:50 -
Nonstop9h 30m
Thu 25/214:45 -
Nonstop9h 55m
Deal found 23/9£592
Fri 27/1118:45 -
Nonstop9h 25m
Wed 2/1214:55 -
Nonstop9h 55m
Deal found 23/9£594
Thu 19/1113:40 -
Nonstop9h 30m
Fri 27/1114:55 -
Nonstop9h 55m
Deal found 22/9£595
Sat 21/1118:45 -
Nonstop9h 35m
Wed 2/1214:45 -
Nonstop10h 15m
Deal found 22/9£596
Sun 14/318:00 -
Nonstop9h 40m
Sun 28/317:45 -
Nonstop10h 18m
Deal found 22/9£599
Sat 21/1118:45 -
Nonstop9h 35m
Fri 15/114:45 -
Nonstop9h 55m
Deal found 23/9£599
Last-minute flights from Seattle to Heathrow
Discover last-minute flight deals from Seattle to Heathrow. Data last updated 27 September 2026 and is based on user searches.
Thu 1/1018:50 -
1 stop19h 50m
Tue 20/1013:50 -
2 stops36h 42m
Deal found 23/9£584
Fri 2/1015:00 -
2 stops22h 00m
Tue 20/1006:55 -
1 stop18h 04m
Deal found 22/9£583
Mon 5/1021:50 -
Nonstop9h 45m
Mon 12/1017:45 -
Nonstop10h 29m
Deal found 23/9£587
Mon 5/1019:15 -
2 stops53h 20m
Mon 12/1010:15 -
2 stops20h 32m
Deal found 22/9£587
Sun 11/1015:00 -
2 stops22h 00m
Sun 18/1007:25 -
1 stop17h 34m
Deal found 23/9£586
Mon 12/1018:05 -
1 stop31h 35m
Mon 26/1018:00 -
1 stop33h 59m
Deal found 22/9£589
Tue 13/1021:50 -
Nonstop9h 45m
Tue 20/1006:30 -
1 stop13h 22m
Deal found 23/9£585
Tue 13/1021:40 -
Nonstop9h 25m
Sat 24/1017:00 -
Nonstop10h 00m
Deal found 23/9£588
Tue 20/1007:00 -
2 stops22h 00m
Tue 27/1013:45 -
2 stops40h 33m
Deal found 24/9£590
Wed 21/1021:50 -
Nonstop9h 45m
Sat 31/1008:55 -
1 stop12h 55m
Deal found 22/9£584
Tue 27/1010:10 -
1 stop18h 40m
Sat 7/1106:30 -
1 stop13h 30m
Deal found 22/9£582
Fri 30/1010:10 -
2 stops16h 10m
Fri 6/1109:00 -
2 stops22h 20m
Deal found 22/9£590
One-way flights from Seattle to Heathrow
Search for one-way flight options from Seattle to Heathrow. Find affordable one-way fares based on user searches. Data last updated 27 September 2026.
Sat 21/1108:40 -
2 stops20h 10m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 26/9£253
Tue 6/1015:55 -
3 stops33h 15m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 24/9£254
Mon 26/1015:35 -
2 stops18h 30m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 24/9£255
Fri 2/1015:55 -
1 stop16h 05m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 23/9£257
Tue 20/1019:00 -
2 stops18h 40m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 24/9£257
Thu 8/1010:30 -
1 stop17h 35m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 24/9£258
Sun 18/1022:15 -
1 stop27h 15m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 24/9£260
Fri 25/1214:35 -
1 stop20h 55m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 24/9£261
Sun 27/1214:35 -
1 stop12h 15m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 26/9£262
Mon 23/1114:35 -
3 stops22h 30m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 25/9£263
Find flight deals from Seattle to Heathrow
Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Heathrow (LHR). 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 27 September 2026.
Customise your flight search to find flights from Seattle to Heathrow 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 7,457,451 searches. Data last updated 27 September 2026.
Use the filters below to find and compare flights from Seattle to London Heathrow Airport that are best for you.
Fly from
Fly to
Route
Depart
Return
Price
Cheapest return flight
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 26/12
23:58-10:15
1 stop26h 17m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£281
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Fri 19/3
18:00-10:40
Nonstop9h 40m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£282
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 31/10
19:05-11:50
1 stop33h 45m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£282
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Wed 28/10
15:15-11:50
1 stop13h 35m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£282
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Tue 16/3
08:30-07:10
3 stops39h 40m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£319
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 24/10
18:30-11:20
Nonstop9h 50m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£320
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Fri 30/10
19:40-12:20
Nonstop9h 40m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£320
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Mon 16/11
16:50-10:40
Nonstop9h 50m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£479
Fastest return journey
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Tue 24/11
18:45-12:20
Nonstop9h 35m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£479
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sun 29/11
16:50-10:40
Nonstop9h 50m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£479
Flights are sorted by cheapest return flights first.
Deals found on 24/9
Showing 1-10 of 22 resultsSorted by cheapest first
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Best time to book a flight from Seattle to Heathrow
Have a flexible travel schedule? Discover the best time to fly to Heathrow from Seattle with our price prediction graph.
SEA-LHR
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 Seattle to London Heathrow Airport
Prices
Airlines
Delays
How far ahead should I book a flight from Seattle to London Heathrow Airport?
The price you pay for your flight from Seattle to London Heathrow Airport may vary depending on when you book. For the best chance of a lower fare, look to book 64 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 Seattle to London Heathrow Airport?
Currently, January is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £517). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £939). 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 SEA to LHR?
Find hourly flight availability from Seattle to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 27 September 2026.
When flying from Seattle to London Heathrow Airport, 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 Seattle to London Heathrow Airport?
Airfare is typical for this route at the moment.
Seattle to London Heathrow Airport flights typically cost between £479 and £731 in January.The cheapest return price found within the last 5 days was £582 on Icelandair (19 Jan–4 Feb).
Weekly flight availability from Seattle to London Heathrow Airport
Explore weekly flight availability from Seattle to Heathrow. 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 27 September 2026.
The most flights from SEA to LHR are scheduled on a Tuesday (25 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (24 on average).
How often are flights from Seattle to London delayed?
About 13% of weekly flights between Seattle and London have experienced delays in the past year, with the average delay time being 131 minutes.
What is the most punctual flight time for Seattle to London flights?
Historically, flights departing at night are less likely to be delayed, whereas flights leaving in the evening tend to experience delays more often.
What day of the week experiences the fewest flight delays on this route?
Saturday tends to have the lowest number of delays on this route, whereas Thursday has historically faced a higher average of delays compared to other days of the week.
Which airline has the best punctuality record on Seattle to London flights?
Over the past year, Virgin Atlantic have had the lowest number of delays on this route, with just 5% of flights being delayed.
Reviews of airlines servicing Heathrow
Get insights into the airlines that provide service to Heathrow. 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 Heathrow. Reviews last updated 27 September 2026.
Read through reviews of airlines operating flights from Seattle to London Heathrow Airport, such as Alaska Airlines,Virgin Atlantic, andBritish Airways. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Alaska has a brilliant crew. And the seats are good. As much as i loved my trip from Heathrow to Seattle, i definitely did not feel the same on the return flight. A lot was due to feeling very cramped and unfortunately for me, i had a kicker behind me and a passenger who did not stop moving (but constantly) next to me. The good was not good and i noticed that most people around me left most of their meal. The ice cream was very nice. I did not have breakfast. However the food was very nice on the way to Seattle
Alaska has a brilliant crew. And the seats are good. As much as i loved my trip from Heathrow to Seattle, i definitely did not feel the same on the return flight. A lot was due to feeling very cramped and unfortunately for me, i had a kicker behind me and a passenger who did not stop moving (but constantly) next to me. The good was not good and i noticed that most people around me left most of their meal. The ice cream was very nice. I did not have breakfast. However the food was very nice on the way to Seattle
Alaska has a brilliant crew. And the seats are good. As much as i loved my trip from Heathrow to Seattle, i definitely did not feel the same on the return flight. A lot was due to feeling very cramped and unfortunately for me, i had a kicker behind me and a passenger who did not stop moving (but constantly) next to me. The good was not good and i noticed that most people around me left most of their meal. The ice cream was very nice. I did not have breakfast. However the food was very nice on the way to Seattle
Alaska has a brilliant crew. And the seats are good. As much as i loved my trip from Heathrow to Seattle, i definitely did not feel the same on the return flight. A lot was due to feeling very cramped and unfortunately for me, i had a kicker behind me and a passenger who did not stop moving (but constantly) next to me. The good was not good and i noticed that most people around me left most of their meal. The ice cream was very nice. I did not have breakfast. However the food was very nice on the way to Seattle
Related info for your journey
Find useful and relevant information for your journey from Seattle to Heathrow. 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 from for flights from Seattle to London Heathrow?
If you book a flight to London Heathrow from Seattle, you will be flying from 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 24 flights from Seattle/Tacoma Intl to London Heathrow per day from 3 different airlines.
How long is the flight from Seattle to London Heathrow Airport?
For as low as £621, United Airlines can have you in London Heathrow Airport from Seattle in 9h 45m. The distance from Seattle to London Heathrow Airport is about 4783 mi. This flight may include one or multiple stops.
What are the cheapest airlines flying from Seattle to London Heathrow Airport round-trip?
Cheapflights users have booked flights from Seattle to London Heathrow Airport round-trip from £467. Other airlines that can offer you cheap pricing are Alaska Airlines, from £498, and Virgin Atlantic, from £530. You may be able to fly from Seattle to London Heathrow Airport for 29% less than the average price by searching for these airlines.
What are the cheapest airlines to fly from Seattle to London Heathrow Airport one-way?
One-way options have recently been found by users for as low as £129 on Icelandair. Other airlines that offer cheap prices include Virgin Atlantic from £221 and British Airways from £246 one-way.
What are the most reliable airlines from Seattle to London Heathrow Airport?
Consider Scandinavian Airlines (95%), KLM (94%) or SAUDIA (94%) when booking your flight. These represent the most reliable airlines when flying from Seattle to London Heathrow Airport.
What are the cheapest flights from Seattle to London Heathrow Airport?
While on average a flight from Seattle to London Heathrow Airport is generally £1,125, our data shows the cheapest flight currently is £239. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £423 for that flight.
Can I find deals for business class flights from Seattle to Heathrow?
Yes. Cheapflights offers flight deals from Seattle to Heathrow 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 Seattle to London Heathrow Airport?
Currently, January is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £517). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £939). 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.
Explore flights to Heathrow departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on 27 September 2026.
Discover the top 3 airlines that operate flights from Seattle to Heathrow. 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 7,457,451 searches. Data last updated 27 September 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 Seattle to Heathrow?
Cheapflights helps you search for flights from Seattle to Heathrow via 900+ travel sites so you don’t have to. After performing a flight search, users can also filter their flight selection by filtering for price, number of stops, airlines, and so on.
Why should you use Cheapflights to find cheap flight tickets from Seattle to Heathrow?
Cheapflights helps you find that perfect flight to Heathrow from Seattle 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 Seattle to Heathrow with no change fees?
Yes! Cheapflights helps users easily find flights from Seattle to Heathrow with no change fees.
Can Cheapflights notify me if prices for flights from Seattle to Heathrow become cheaper?
Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!
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