Cheap flights from Seattle to London Heathrow Airport from C$ 432
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 4/10. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
7 Oct — 14 Oct1
Round-trip
1 adult
Economy
Round-trip
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 65 days in advance, depart on a Saturday or Sunday and return on a Monday
Cheap flight deals from Seattle to Heathrow
Enter your travel dates to find the best prices.
Cheapest
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 7 September 2026.
Fri 2/103:55 p.m. -
1 stop16h 05m
Sat 10/1010:20 a.m. -
1 stop35h 25m
Deal found 2/9C$ 1,031
Sat 3/103:55 p.m. -
1 stop18h 35m
Tue 13/107:05 a.m. -
2 stops23h 59m
Deal found 2/9C$ 1,043
Sat 3/103:55 p.m. -
1 stop18h 35m
Sat 10/106:40 a.m. -
2 stops15h 05m
Deal found 5/9C$ 1,049
Tue 6/103:55 p.m. -
1 stop17h 45m
Wed 21/107:05 a.m. -
2 stops23h 59m
Deal found 2/9C$ 1,050
Sun 11/103:55 p.m. -
2 stops16h 30m
Mon 19/107:05 a.m. -
2 stops23h 59m
Deal found 7/9C$ 1,054
Tue 6/103:55 p.m. -
1 stop17h 45m
Tue 13/107:05 a.m. -
2 stops23h 59m
Deal found 7/9C$ 1,056
Tue 8/122:35 p.m. -
1 stop20h 55m
Sun 17/112:15 p.m. -
1 stop12h 45m
Deal found 4/9C$ 1,058
Sun 15/112:35 p.m. -
1 stop12h 15m
Sat 9/18:35 p.m. -
1 stop28h 25m
Deal found 4/9C$ 1,061
Sun 20/93:55 p.m. -
2 stops20h 00m
Fri 2/106:40 p.m. -
1 stop27h 05m
Deal found 7/9C$ 1,063
Fri 13/1110:39 a.m. -
2 stops38h 41m
Mon 16/116:40 a.m. -
2 stops23h 24m
Deal found 5/9C$ 1,064
Best flights from Seattle to Heathrow
Discover carefully curated flight deals from Seattle to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated 7 September 2026.
Tue 22/93:55 p.m. -
1 stop16h 05m
Sat 3/101:55 p.m. -
2 stops31h 50m
Deal found 2/9C$ 1,082
Sun 31/16:50 p.m. -
Nonstop9h 30m
Thu 4/22:45 p.m. -
Nonstop9h 55m
Deal found 6/9C$ 1,195
Wed 28/105:45 p.m. -
Nonstop9h 55m
Tue 3/116:30 a.m. -
1 stop13h 17m
Deal found 3/9C$ 1,248
Thu 21/12:30 p.m. -
2 stops20h 00m
Mon 25/110:20 a.m. -
2 stops20h 00m
Deal found 6/9C$ 1,154
Wed 13/12:30 p.m. -
2 stops23h 10m
Wed 20/16:40 p.m. -
2 stops35h 40m
Deal found 3/9C$ 1,169
Fri 5/27:20 a.m. -
2 stops24h 40m
Mon 8/26:40 p.m. -
2 stops35h 22m
Deal found 2/9C$ 1,170
Tue 12/17:20 a.m. -
2 stops18h 00m
Sun 17/16:40 a.m. -
2 stops22h 10m
Deal found 5/9C$ 1,188
Wed 13/12:30 p.m. -
2 stops19h 10m
Tue 19/16:40 a.m. -
2 stops23h 22m
Deal found 5/9C$ 1,188
Thu 14/12:30 p.m. -
2 stops20h 00m
Tue 19/16:40 a.m. -
2 stops23h 22m
Deal found 5/9C$ 1,188
Thu 12/113:13 p.m. -
2 stops18h 27m
Tue 17/116:40 a.m. -
2 stops21h 33m
Deal found 3/9C$ 1,211
Sat 19/97:15 a.m. -
2 stops18h 20m
Wed 23/126:40 p.m. -
2 stops35h 02m
Deal found 7/9C$ 1,229
Thu 5/1110:51 a.m. -
2 stops21h 09m
Mon 9/116:40 a.m. -
2 stops24h 46m
Deal found 6/9C$ 1,237
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 7 September 2026.
Mon 11/16:45 p.m. -
Nonstop9h 25m
Tue 19/12:55 p.m. -
Nonstop9h 55m
Deal found 5/9C$ 1,164
Sun 10/16:55 p.m. -
Nonstop9h 25m
Sun 17/12:55 p.m. -
Nonstop9h 55m
Deal found 4/9C$ 1,172
Mon 11/16:55 p.m. -
Nonstop9h 25m
Wed 20/12:55 p.m. -
Nonstop9h 55m
Deal found 5/9C$ 1,175
Sun 10/16:55 p.m. -
Nonstop9h 25m
Tue 19/12:55 p.m. -
Nonstop9h 55m
Deal found 5/9C$ 1,179
Sun 10/16:55 p.m. -
Nonstop9h 25m
Wed 20/12:55 p.m. -
Nonstop9h 55m
Deal found 5/9C$ 1,180
Mon 11/16:55 p.m. -
Nonstop9h 25m
Sat 16/12:55 p.m. -
Nonstop9h 55m
Deal found 4/9C$ 1,182
Sun 10/16:55 p.m. -
Nonstop9h 25m
Mon 18/12:55 p.m. -
Nonstop9h 55m
Deal found 4/9C$ 1,188
Wed 13/16:55 p.m. -
Nonstop9h 25m
Tue 19/12:45 p.m. -
Nonstop10h 05m
Deal found 4/9C$ 1,195
Sun 10/16:55 p.m. -
Nonstop9h 25m
Wed 3/22:45 p.m. -
Nonstop10h 05m
Deal found 2/9C$ 1,197
Mon 11/16:45 p.m. -
Nonstop9h 25m
Mon 18/12:45 p.m. -
Nonstop10h 05m
Deal found 5/9C$ 1,202
Wed 9/124:50 p.m. -
Nonstop9h 50m
Wed 16/1212:20 p.m. -
Nonstop10h 30m
Deal found 3/9C$ 1,220
Last-minute flights from Seattle to Heathrow
Discover last-minute flight deals from Seattle to Heathrow. Data last updated 7 September 2026 and is based on user searches.
Sun 20/93:55 p.m. -
2 stops20h 00m
Fri 2/107:30 p.m. -
1 stop26h 15m
Deal found 5/9C$ 1,061
Fri 25/93:55 p.m. -
2 stops16h 30m
Thu 8/107:05 a.m. -
2 stops38h 40m
Deal found 3/9C$ 1,065
Fri 2/103:55 p.m. -
1 stop16h 05m
Sat 10/1010:20 a.m. -
1 stop35h 25m
Deal found 2/9C$ 1,031
Sat 3/103:55 p.m. -
1 stop18h 35m
Tue 13/107:05 a.m. -
2 stops23h 59m
Deal found 2/9C$ 1,043
Sat 3/103:55 p.m. -
1 stop18h 35m
Sat 10/106:40 a.m. -
2 stops15h 05m
Deal found 5/9C$ 1,049
Tue 6/103:55 p.m. -
1 stop17h 45m
Wed 21/107:05 a.m. -
2 stops23h 59m
Deal found 2/9C$ 1,050
Tue 6/103:55 p.m. -
1 stop17h 45m
Tue 13/107:05 a.m. -
2 stops23h 59m
Deal found 7/9C$ 1,056
Sun 11/103:55 p.m. -
2 stops16h 30m
Mon 19/107:05 a.m. -
2 stops23h 59m
Deal found 7/9C$ 1,054
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 7 September 2026.
Sun 4/103:55 p.m. -
2 stops21h 25m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 4/9C$ 432
Mon 14/99:40 p.m. -
1 stop15h 05m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 3/9C$ 434
Wed 21/1011:55 p.m. -
1 stop22h 35m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 6/9C$ 443
Sat 3/103:55 p.m. -
2 stops45h 25m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 5/9C$ 444
Fri 9/103:55 p.m. -
2 stops33h 00m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 5/9C$ 447
Mon 11/16:55 p.m. -
Nonstop9h 25m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 5/9C$ 448
Tue 2/36:50 p.m. -
Nonstop9h 30m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 6/9C$ 450
Fri 2/107:00 p.m. -
1 stop32h 55m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 6/9C$ 451
Mon 28/1211:15 p.m. -
1 stop23h 05m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 6/9C$ 455
Sat 19/99:40 p.m. -
1 stop27h 50m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 7/9C$ 457
Sat 21/112:35 p.m. -
1 stop12h 15m
Wed 31/1212:00 a.m. -
Nonstop0h 00m
Deal found 2/9C$ 481
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 7 September 2026.
Customize 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 7 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 round-trip
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Wed 13/1
8:30 a.m.-9:10 a.m.
2 stops16h 40m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 448
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 27/2
2:35 p.m.-7:30 p.m.
1 stop20h 55m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 448
Quickest round-trip
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Mon 11/1
6:55 p.m.-12:20 p.m.
Nonstop9h 25m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 448
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Fri 8/1
2:35 p.m.-10:50 a.m.
1 stop12h 15m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 448
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sun 6/12
4:50 p.m.-10:40 a.m.
Nonstop9h 50m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 450
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Wed 3/3
6:55 p.m.-12:20 p.m.
Nonstop9h 25m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 450
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sun 4/10
5:30 p.m.-11:20 a.m.
Nonstop9h 50m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 516
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Wed 21/10
5:00 a.m.-6:45 a.m.
2 stops17h 45m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 516
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 9/1
4:55 p.m.-10:40 a.m.
Nonstop9h 45m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 517
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Wed 28/10
3:15 p.m.-11:50 a.m.
1 stop13h 35m
London Heathrow
Wed 31/12
12:00 a.m.-3:00 p.m.
Nonstop0h 00m
C$ 517
Flights are sorted by cheapest round-trip flights first.
Deals found on 5/9
Showing 1-10 of 24 resultsSorted by cheapest first
1
2
3
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 round-trip 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 best time to book flights from Seattle to London Heathrow Airport is 64 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 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 C$ 896). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,722). 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 7 September 2026.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Seattle to London Heathrow Airport as you normally would.
How much does it cost to fly round-trip 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 C$ 1,078 and C$ 1,466 in October.The cheapest round-trip price found within the last 5 days was C$ 1,031 on Scandinavian Airlines (2 Oct-10 Oct).
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 7 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 14% of weekly flights between Seattle and London have experienced delays in the past year, with the average delay time being 139 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 has 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 7 September 2026.
Read through reviews of airlines operating flights from Seattle to London Heathrow Airport, such as Icelandair. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
First time Iceland Air. Ridiculously small amount of leg room, flight was hotter than hades and people kept requesting for cooler air that never came. You pay for everything, no food of any kind unless you pay which I've never seen on a flight of this length. Just seemed like they are cheap as possible about everything. Won't fly with them again if I can avoid it.
First time Iceland Air. Ridiculously small amount of leg room, flight was hotter than hades and people kept requesting for cooler air that never came. You pay for everything, no food of any kind unless you pay which I've never seen on a flight of this length. Just seemed like they are cheap as possible about everything. Won't fly with them again if I can avoid it.
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?
Seattle/Tacoma Intl (SEA) is the airport you will fly out of if you book a flight from Seattle to London Heathrow. You should not have trouble finding flights to London Heathrow from Seattle/Tacoma Intl; the airport handles an average of 24 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 1 airline has flights from the Seattle airport to London Heathrow. It is only a 18.4 km journey to Seattle/Tacoma Intl (SEA) from Seattle’s city centre.
How long is the flight from Seattle to London Heathrow Airport?
There are many flights that can get you from Seattle to London Heathrow Airport in 16h 05m. Fly via Scandinavian Airlines to get the fastest option. Airlines will cover a distance of 7697 km.
What is the cheapest airline to fly from Seattle to London Heathrow Airport round-trip?
Flying on Icelandair is currently your cheapest option to London Heathrow Airport, with prices starting at C$ 697. Users have found that Icelandair is 42% cheaper than the other options available to this destination.
What are the most reliable airlines from Seattle to London Heathrow Airport?
Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to London Heathrow Airport on time: Scandinavian Airlines (95%), SAUDIA (95%), KLM (92%).
What are the cheapest flights from Seattle to London Heathrow Airport?
While on average a flight from Seattle to London Heathrow Airport is generally C$ 1,236, our data shows the cheapest flight currently is C$ 523. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay C$ 1,447 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 C$ 896). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,722). 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 7 September 2026.
Browse through other flights departing from Seattle. Flights are based on user searches made on Cheapflights and were last updated on 7 September 2026.
Discover the top airline 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 7 September 2026.
Find the best flight deals on Cheapflights, where travelers 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?
900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Heathrow from Seattle today with Cheapflights!
Why should you use Cheapflights to find cheap flight tickets from Seattle to Heathrow?
Millions of users choose and trust Cheapflights to book the best flight deals from Seattle to Heathrow for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.
Can Cheapflights find flights from Seattle to Heathrow with no change fees?
Users can book flights with no change fees policies with our dedicated filters. Book flights from Seattle to Heathrow flexibly with Cheapflights today.
Can Cheapflights notify me if prices for flights from Seattle to Heathrow become cheaper?
Yes, Cheapflights offers price alerts on Seattle to Heathrow flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.
100% Free
Cheapflights is completely free to use, so you can start saving the moment you arrive.
Book with Flexibility
Our users can plan ahead with confidence and find flights with no change fees
Travel Smart
Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.
We value your privacy
Cheapflights and its partners wish to use cookies or similar technologies to store and/or access information on and about your device and process personal data such as your IP address, device identifiers etc., in order to improve your experience on the site, to analyze navigation, to offer and measure personalized advertising, and to facilitate sharing on social networks. We also allow the use of third-party cookies (including those from our advertising partners) on our sites.
By clicking 'Accept', you consent to your data being processed by 0 vendors on this web site for the purposes described in this notice. You can review the vendors and their individual processing purposes on the .
To review individual processing purposes and cookie categories, please click ’Select individual purposes’. You can review and update your choices anytime by clicking the ’Privacy Preferences’ link in the page side navigation.