$307+ Cheap flights from Seattle (SEA) to Heathrow (LHR)
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 10/16. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
Oct 1 — Oct 81
Round-trip
1 adult, Economy
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Find cheap flights from Seattle to Heathrow with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.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 Monday or Wednesday and return on a Monday
Cheap flight deals from Seattle to Heathrow
Cheapest
Best
Last-minute
One-way
Cheapest flights from Seattle to HeathrowExplore 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 September 1, 2026.
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 September 1, 2026.
This oojo deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/223:55 pm -
1 stop17h 45m
Sat 10/101:55 pm -
2 stops31h 50m
Deal found 9/1![Scandinavian Airlines logo]()
$740
This Scandinavian Airlines deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/63:55 pm -
1 stop16h 05m
Wed 10/217:05 am -
2 stops23h 59m
Deal found 8/28![Scandinavian Airlines logo]()
$741
This oojo deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/223:55 pm -
1 stop17h 45m
Thu 10/19:05 pm -
2 stops24h 40m
Deal found 9/1![Scandinavian Airlines logo]()
$742
This Mytrip deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/197:00 pm -
2 stops18h 40m
Wed 11/48:35 pm -
1 stop28h 25m
Deal found 8/28![Multiple Airlines logo]()
$743
This Gotogate deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/162:35 pm -
1 stop12h 15m
Tue 1/1212:15 pm -
1 stop12h 45m
Deal found 9/1![Icelandair logo]()
$745
This Booking.com deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/162:35 pm -
1 stop12h 15m
Tue 11/2412:15 pm -
1 stop12h 45m
Deal found 9/1![Icelandair logo]()
$747
This oojo deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/43:55 pm -
1 stop21h 45m
Tue 10/137:05 am -
2 stops23h 59m
Deal found 9/1![Scandinavian Airlines logo]()
$749
This Scandinavian Airlines deal was found by Cheapflights users on 8/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/23:55 pm -
1 stop13h 40m
Thu 10/87:05 am -
2 stops38h 40m
Deal found 8/31![Scandinavian Airlines logo]()
$750
This Cheapflightsfares deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/137:00 pm -
1 stop17h 20m
Tue 10/201:05 pm -
1 stop15h 35m
Deal found 9/1![Icelandair logo]()
$752
Best flights from Seattle to HeathrowDiscover 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 September 1, 2026.
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 September 1, 2026.
This Scandinavian Airlines deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/93:55 pm -
2 stops18h 35m
Fri 10/166:40 am -
2 stops24h 09m
Deal found 8/28![Scandinavian Airlines logo]()
$764
This Icelandair deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Icelandair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/22:35 pm -
1 stop12h 15m
Fri 12/1812:15 pm -
1 stop12h 45m
Deal found 9/1![Icelandair logo]()
$792
This United Airlines deal was found by Cheapflights users on 8/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/208:30 am -
2 stops16h 50m
Fri 10/2310:50 am -
1 stop14h 09m
Deal found 8/30![United Airlines logo]()
$908
This Alaska Airlines deal was found by Cheapflights users on 8/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/136:55 pm -
Nonstop9h 25m
Sun 1/242:45 pm -
Nonstop10h 05m
Deal found 8/31![Alaska Airlines logo]()
$915
This Delta deal was found by Cheapflights users on 8/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/49:50 pm -
Nonstop9h 45m
Sun 10/116:30 am -
1 stop13h 22m
Deal found 8/29![Delta logo]()
$953
This Scandinavian Airlines deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/133:55 pm -
2 stops16h 30m
Thu 9/177:05 am -
2 stops24h 15m
Deal found 8/28![Scandinavian Airlines logo]()
$805
This Alaska Airlines deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 1/176:55 pm -
Nonstop9h 25m
Sat 1/302:45 pm -
Nonstop10h 05m
Deal found 8/28![Alaska Airlines logo]()
$916
This Scandinavian Airlines deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/207:20 am -
2 stops24h 40m
Wed 1/276:40 pm -
2 stops35h 40m
Deal found 8/28![Scandinavian Airlines logo]()
$847
This United Airlines deal was found by Cheapflights users on 8/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/1411:04 pm -
1 stop23h 51m
Thu 9/176:55 am -
1 stop18h 04m
Deal found 8/31![United Airlines logo]()
$948
This Scandinavian Airlines deal was found by Cheapflights users on 8/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/110:39 am -
2 stops23h 01m
Thu 11/126:40 am -
2 stops24h 15m
Deal found 8/29![Scandinavian Airlines logo]()
$860
This Scandinavian Airlines deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 1/152:30 pm -
2 stops20h 00m
Wed 2/36:40 am -
2 stops20h 25m
Deal found 8/28![Scandinavian Airlines logo]()
$861
This Scandinavian Airlines deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/57:38 am -
2 stops17h 42m
Thu 12/175:00 pm -
2 stops37h 09m
Deal found 9/1![Scandinavian Airlines logo]()
$890
Last-minute flights from Seattle to HeathrowDiscover last-minute flight deals from Seattle to Heathrow. Data last updated September 1, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Heathrow. Data last updated September 1, 2026 and is based on user searches.
This oojo deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/223:55 pm -
1 stop17h 45m
Sat 10/101:55 pm -
2 stops31h 50m
Deal found 9/1![Scandinavian Airlines logo]()
$740
This oojo deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/223:55 pm -
1 stop17h 45m
Thu 10/19:05 pm -
2 stops24h 40m
Deal found 9/1![Scandinavian Airlines logo]()
$742
This Scandinavian Airlines deal was found by Cheapflights users on 8/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/23:55 pm -
1 stop13h 40m
Thu 10/87:05 am -
2 stops38h 40m
Deal found 8/31![Scandinavian Airlines logo]()
$750
This oojo deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/43:55 pm -
1 stop21h 45m
Tue 10/137:05 am -
2 stops23h 59m
Deal found 9/1![Scandinavian Airlines logo]()
$749
This Scandinavian Airlines deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/63:55 pm -
1 stop16h 05m
Wed 10/217:05 am -
2 stops23h 59m
Deal found 8/28![Scandinavian Airlines logo]()
$741
This Cheapflightsfares deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/137:00 pm -
1 stop17h 20m
Tue 10/201:05 pm -
1 stop15h 35m
Deal found 9/1![Icelandair logo]()
$752
This Mytrip deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/197:00 pm -
2 stops18h 40m
Wed 11/48:35 pm -
1 stop28h 25m
Deal found 8/28![Multiple Airlines logo]()
$743
This Gotogate deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/197:00 pm -
1 stop32h 55m
Wed 11/412:15 pm -
1 stop12h 45m
Deal found 8/28![Icelandair logo]()
$745
One-way flights from Seattle to HeathrowSearch for one-way flight options from Seattle to Heathrow. Find affordable one-way fares based on user searches. Data last updated September 1, 2026.
Search for one-way flight options from Seattle to Heathrow. Find affordable one-way fares based on user searches. Data last updated September 1, 2026.
This oojo deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/163:40 pm -
1 stop12h 15m
Deal found 9/1![Icelandair logo]()
$307
This Kiwi.com deal was found by Cheapflights users on 8/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/253:55 pm -
1 stop16h 05m
Deal found 8/29![Scandinavian Airlines logo]()
$309
This Kiwi.com deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/273:55 pm -
3 stops20h 00m
Deal found 8/28![Scandinavian Airlines logo]()
$310
This Kiwi.com deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/293:55 pm -
3 stops20h 00m
Deal found 8/28![Scandinavian Airlines logo]()
$312
This Kiwi.com deal was found by Cheapflights users on 8/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/263:55 pm -
3 stops41h 05m
Deal found 8/28![Scandinavian Airlines logo]()
$313
This JetBlue deal was found by Cheapflights users on 9/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/199:40 pm -
1 stop15h 05m
Deal found 9/1![JetBlue logo]()
$314
This Expedia deal was found by Cheapflights users on 8/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/286:45 pm -
Nonstop9h 25m
Deal found 8/31![Iberia logo]()
$315
This Kiwi.com deal was found by Cheapflights users on 8/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/253:35 pm -
2 stops23h 05m
Deal found 8/30![Multiple Airlines logo]()
$316
This Mytrip deal was found by Cheapflights users on 8/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/93:55 pm -
3 stops21h 00m
Deal found 8/31![Multiple Airlines logo]()
$317
This Expedia deal was found by Cheapflights users on 8/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/2810:10 am -
1 stop17h 40m
Deal found 8/31![Air Canada logo]()
$318
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 September 1, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $740 (oojo) |
One-way from | $307 (oojo) |
Popular in | June |
Cheapest in | January |
Average price | $901 |
Good round-trip deal | $952 or less |
Good one-way deal | $419 or less |
Cheapflights Fare Finder
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 September 1, 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
Cheapest round-trip
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Fri 10/9
3:55 pm-6:30 pm
2 stops18h 35m
London Heathrow
Fri 10/16
6:40 am-10:49 pm
2 stops24h 09m
$764
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Wed 12/2
2:35 pm-10:50 am
1 stop12h 15m
London Heathrow
Fri 12/18
12:15 pm-5:00 pm
1 stop12h 45m
$792
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sun 9/13
3:55 pm-4:25 pm
2 stops16h 30m
London Heathrow
Thu 9/17
7:05 am-11:20 pm
2 stops24h 15m
$805
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Wed 1/20
7:20 am-4:00 pm
2 stops24h 40m
London Heathrow
Wed 1/27
6:40 pm-10:20 pm
2 stops35h 40m
$847
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sun 11/1
10:39 am-5:40 pm
2 stops23h 01m
London Heathrow
Thu 11/12
6:40 am-10:55 pm
2 stops24h 15m
$860
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Fri 1/15
2:30 pm-6:30 pm
2 stops20h 00m
London Heathrow
Wed 2/3
6:40 am-7:05 pm
2 stops20h 25m
$861
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 12/5
7:38 am-9:20 am
2 stops17h 42m
London Heathrow
Thu 12/17
5:00 pm-10:09 pm
2 stops37h 09m
$890
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Tue 10/20
8:30 am-9:20 am
2 stops16h 50m
London Heathrow
Fri 10/23
10:50 am-4:59 pm
1 stop14h 09m
$908
Quickest round-trip
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Wed 1/13
6:55 pm-12:20 pm
Nonstop9h 25m
London Heathrow
Sun 1/24
2:45 pm-4:50 pm
Nonstop10h 05m
$915
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sun 1/17
6:55 pm-12:20 pm
Nonstop9h 25m
London Heathrow
Sat 1/30
2:45 pm-4:50 pm
Nonstop10h 05m
$916
Showing 1-10 of 22 resultsSorted by cheapest first
Compare providers for flights from Seattle to Heathrow
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Heathrow in September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy2 stars | Trust Score*1 star | |
| Price Accuracy- | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy2 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on Seattle-London Heathrow Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-London Heathrow Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-London Heathrow Airport flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Seattle-London Heathrow Airport flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-London Heathrow Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
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
More
How far ahead should I book a flight from Seattle to London Heathrow Airport?
Booking 64 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to London Heathrow Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.
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 $642). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of $1,244). 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 September 1, 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 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 last year, Virgin Atlantic have had the lowest number of delays on this route, with just 5% of flights being delayed.
What’s the top layover airport for flights from Seattle to London Heathrow Airport?
Share of 1-stop round-trip flights from Seattle to London Heathrow Airport chosen by Cheapflights users in the past 12 months, using the same layover each way.
Reykjavik (KEF) – chosen by Cheapflights users on 82% of 1-stop itineraries from Seattle to London Heathrow Airport on Cheapflights.
What’s the cheapest layover airport for flights from Seattle to London Heathrow Airport?
Average round-trip fare for 1-stop flights from Seattle to London Heathrow Airport, chosen by Cheapflights users in the past 12 months, with the same layover each way.
Montreal (YUL) is the most affordable 1-stop option, with an average round-trip price of $631.
What’s the fastest layover option from Seattle to London Heathrow Airport?
Shortest average travel time for 1-stop one-way flights from Seattle to London Heathrow Airport, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.
Flights via Reykjavik (KEF) have the shortest average one-way travel time for 1-stop routes: 12h 35m.
Which airport typically offers the quickest layover for flights from Seattle to London Heathrow Airport?
Average layover duration for 1-stop one-way flights from Seattle to London Heathrow Airport, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.
Flights via Istanbul (IST) offer the fastest connection on this route, with an average layover time of 2h 15m.
The best insider tips for Seattle to London Heathrow Airport flights
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Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to London Heathrow Airport trip
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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 September 1, 2026.
Read reviews from past customers who have flown Alaska Airlines,Delta, andVirgin Atlantic from Seattle to London Heathrow Airport. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Food
7.0
Entertainment
7.0
Overall
7.9
Comfort
7.8
Crew
8.5
Boarding
8.1
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Entertainment
7.0
Overall
7.9
Comfort
7.8
Crew
8.5
Boarding
8.1
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Entertainment
7.0
Overall
7.9
Comfort
7.8
Crew
8.5
Boarding
8.1
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Entertainment
7.0
Overall
7.9
Comfort
7.8
Crew
8.5
Boarding
8.1
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Entertainment
7.0
Overall
7.9
Comfort
7.8
Crew
8.5
Boarding
8.1
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Entertainment
7.0
Overall
7.9
Comfort
7.8
Crew
8.5
Boarding
8.1
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
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.
Traveling to a place near London Heathrow Airport?
Book flights to London Heathrow Airport if you plan to visit one of these locationsIlford
Dorking
Winchester
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Gatwick
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Southend-on-Sea
Basingstoke
Watford
Northampton
Dartford
Croydon
Chipping Norton
Kingston upon Thames
Eastbourne
Slough
Stansted
Sutton
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Top 10 airlines flying from Seattle to Heathrow
Discover the top 10 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 September 1, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$500 | Average$720 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$505 | Average$702 | FlexibilityNo cancel fee | On-time76% | |
| Cheapest$545 | Average$972 | FlexibilityNo cancel fee | On-time72% | |
| Cheapest$559 | Average$986 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$559 | Average$865 | FlexibilityNo cancel fee | On-time70% | |
| Cheapest$560 | Average$694 | FlexibilityNo cancel fee | On-time76% | |
| Cheapest$569 | Average$915 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$569 | Average$821 | FlexibilityNo cancel fee | On-time77% | |
| Cheapest$595 | Average$978 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$639 | Average$866 | FlexibilityNo cancel fee | On-time77% |