Cheap flights from Seattle to London Heathrow Airport from £256
This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 3/4. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
15 Dec — 22 Dec1
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 56 days in advance, depart on a Monday or Wednesday 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 15 November 2026.
Sat 5/1214:35 -
1 stop20h 55m
Sun 13/1212:15 -
1 stop12h 45m
Deal found 11/11£503
Fri 27/1114:35 -
1 stop20h 55m
Sat 12/1220:35 -
1 stop28h 25m
Deal found 11/11£504
Sun 29/1114:35 -
1 stop20h 55m
Sat 12/1220:35 -
1 stop28h 25m
Deal found 14/11£508
Tue 8/1208:30 -
3 stops29h 10m
Thu 24/1210:20 -
2 stops34h 40m
Deal found 11/11£524
Tue 24/1114:35 -
1 stop12h 15m
Tue 8/1212:15 -
1 stop12h 45m
Deal found 14/11£526
Tue 8/1207:45 -
3 stops29h 35m
Tue 15/1213:55 -
2 stops31h 05m
Deal found 10/11£529
Mon 14/1214:35 -
1 stop20h 55m
Mon 11/120:35 -
1 stop28h 25m
Deal found 10/11£533
Sat 28/1114:35 -
1 stop12h 15m
Sat 5/1212:15 -
1 stop12h 45m
Deal found 11/11£535
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 15 November 2026.
Wed 9/1216:50 -
Nonstop9h 50m
Tue 15/1212:20 -
Nonstop10h 30m
Deal found 11/11£617
Mon 12/421:30 -
Nonstop9h 35m
Thu 22/417:00 -
Nonstop10h 10m
Deal found 12/11£626
Wed 27/116:55 -
Nonstop9h 45m
Wed 10/212:20 -
Nonstop10h 25m
Deal found 10/11£629
Mon 11/107:15 -
2 stops24h 45m
Wed 20/106:40 -
2 stops24h 45m
Deal found 14/11£639
Sun 13/1208:09 -
2 stops18h 16m
Tue 15/1209:00 -
2 stops19h 47m
Deal found 12/11£659
Wed 9/1207:15 -
1 stop25h 15m
Thu 17/1210:45 -
1 stop14h 10m
Deal found 11/11£627
Thu 11/317:00 -
Nonstop9h 40m
Mon 29/317:45 -
Nonstop10h 18m
Deal found 10/11£705
Sat 13/317:28 -
1 stop36h 02m
Mon 29/314:05 -
2 stops29h 35m
Deal found 10/11£708
Wed 13/116:55 -
Nonstop9h 45m
Sun 17/106:20 -
1 stop16h 53m
Deal found 11/11£658
Tue 15/1205:05 -
2 stops20h 05m
Fri 25/1211:10 -
2 stops20h 06m
Deal found 13/11£717
Wed 9/1216:50 -
Nonstop9h 50m
Sun 13/1211:20 -
1 stop15h 23m
Deal found 11/11£662
Wed 7/421:50 -
Nonstop9h 45m
Wed 21/411:45 -
1 stop12h 35m
Deal found 12/11£665
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 15 November 2026.
Tue 5/118:40 -
Nonstop9h 40m
Tue 12/114:45 -
Nonstop10h 05m
Deal found 11/11£601
Wed 3/216:55 -
Nonstop9h 45m
Wed 10/212:20 -
Nonstop10h 25m
Deal found 12/11£608
Sun 3/116:55 -
Nonstop9h 45m
Tue 19/112:20 -
Nonstop10h 25m
Deal found 9/11£611
Tue 8/1216:50 -
Nonstop9h 50m
Fri 25/1212:20 -
Nonstop10h 30m
Deal found 9/11£611
Tue 8/1216:50 -
Nonstop9h 50m
Fri 25/1212:20 -
Nonstop10h 30m
Deal found 10/11£616
Wed 9/1216:50 -
Nonstop9h 50m
Tue 15/1212:20 -
Nonstop10h 30m
Deal found 11/11£617
Tue 8/1216:50 -
Nonstop9h 50m
Tue 15/1212:20 -
Nonstop10h 30m
Deal found 10/11£617
Mon 4/118:45 -
Nonstop9h 35m
Thu 14/114:45 -
Nonstop10h 05m
Deal found 14/11£621
Mon 4/118:45 -
Nonstop9h 35m
Tue 19/114:45 -
Nonstop10h 05m
Deal found 13/11£622
Tue 8/1218:45 -
Nonstop9h 35m
Tue 19/114:45 -
Nonstop10h 05m
Deal found 10/11£623
Sun 3/118:45 -
Nonstop9h 35m
Thu 14/114:45 -
Nonstop10h 05m
Deal found 12/11£623
Last-minute flights from Seattle to Heathrow
Discover last-minute flight deals from Seattle to Heathrow. Data last updated 15 November 2026 and is based on user searches.
Fri 20/1114:35 -
1 stop12h 15m
Wed 25/1112:15 -
1 stop12h 45m
Deal found 10/11£632
Sun 22/1114:35 -
1 stop12h 15m
Tue 8/1212:15 -
1 stop12h 45m
Deal found 10/11£621
Sun 22/1114:35 -
1 stop12h 15m
Mon 7/1220:35 -
1 stop28h 25m
Deal found 10/11£623
Sun 22/1107:27 -
2 stops24h 33m
Thu 26/1110:20 -
2 stops19h 44m
Deal found 10/11£638
Mon 23/1107:45 -
3 stops29h 35m
Tue 1/1209:55 -
3 stops34h 05m
Deal found 10/11£589
Mon 23/1107:38 -
2 stops24h 22m
Tue 1/1218:40 -
2 stops35h 22m
Deal found 13/11£635
Tue 24/1114:35 -
1 stop12h 15m
Tue 8/1212:15 -
1 stop12h 45m
Deal found 14/11£526
Tue 24/1107:38 -
2 stops24h 22m
Tue 8/1218:40 -
2 stops35h 22m
Deal found 14/11£636
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 15 November 2026.
Fri 29/117:52 -
1 stop34h 58m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 10/11£256
Wed 25/1114:35 -
1 stop20h 55m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 10/11£258
Sun 22/1117:48 -
1 stop35h 02m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 10/11£259
Sun 10/111:00 -
2 stops17h 50m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 10/11£260
Sun 29/1114:35 -
2 stops19h 55m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 10/11£267
Wed 13/114:35 -
2 stops19h 55m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 10/11£269
Sun 10/114:35 -
2 stops17h 50m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 11/11£269
Mon 11/114:35 -
2 stops23h 00m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 10/11£270
Mon 18/114:35 -
3 stops23h 00m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 14/11£271
Tue 1/1214:35 -
1 stop20h 55m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 14/11£273
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 15 November 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 15 November 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 3/4
07:45-07:25
2 stops39h 40m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£256
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 8/5
15:00-08:50
Nonstop9h 50m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£288
Fastest return journey
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Fri 30/4
20:20-13:45
Nonstop9h 25m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£288
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Thu 29/4
20:20-13:45
Nonstop9h 25m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£288
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 27/2
05:00-09:10
3 stops20h 10m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£291
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Tue 8/12
07:25-10:50
2 stops19h 25m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£303
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Tue 8/12
15:21-17:40
2 stops18h 19m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£328
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Mon 26/4
18:50-22:00
3 stops19h 10m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£452
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Wed 12/5
08:30-10:00
3 stops41h 30m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£455
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Tue 8/12
13:30-07:00
Nonstop9h 30m
London Heathrow
Wed 31/12
00:00-15:00
Nonstop0h 00m
£475
Flights are sorted by cheapest return flights first.
Deals found on 10/11
Showing 1-10 of 23 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 £550). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £944). 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 15 November 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 below average for this route at the moment.
Seattle to London Heathrow Airport flights typically cost between £562 and £880 in January.The cheapest return price found within the last 5 days was £483 on Icelandair (4 Jan–15 Jan).
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 15 November 2026.
The most flights from SEA to LHR are scheduled on a Monday (13 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (13 on average).
How often are flights from Seattle to London delayed?
About 14% of weekly flights between Seattle and London have experienced delays in the past year, with the average delay time being 130 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 15 November 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.
Super, I would love to fly out again and again with my favourite Alaska Airlines
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 13 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 £626, Delta can have you in London Heathrow Airport from Seattle in 9h 35m. The distance from Seattle to London Heathrow Airport is about 4783 mi. All flights are typically direct.
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 £499. Other airlines that can offer you cheap pricing are British Airways, from £527, and Virgin Atlantic, from £586. You may be able to fly from Seattle to London Heathrow Airport for 28% 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 £202 and British Airways from £246 one-way.
What are the most reliable airlines from Seattle to London Heathrow Airport?
Consider Scandinavian Airlines (97%), KLM (96%) or SAUDIA (96%) 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 £652, our data shows the cheapest flight currently is £246. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £433 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 £550). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £944). 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 15 November 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 15 November 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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