$335+ Cheap flights from Seattle (SEA) to Heathrow (LHR)
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 11/21. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
Oct 26 — Nov 21
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 35 days in advance, depart on a Monday or Tuesday 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 26, 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 26, 2026.
This Gotogate deal was found by Cheapflights users on 9/21. 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 9/2810:50 am -
2 stops17h 00m
Tue 10/1310:15 am -
2 stops16h 17m
Deal found 9/21![Air Canada logo]()
$771
This Delta deal was found by Cheapflights users on 9/21. 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.
Thu 10/159:50 pm -
Nonstop9h 45m
Thu 10/226:30 am -
1 stop18h 05m
Deal found 9/21![Delta logo]()
$772
This Air Canada deal was found by Cheapflights users on 9/21. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/810:10 am -
1 stop17h 40m
Tue 11/106:35 am -
2 stops19h 47m
Deal found 9/21![Multiple Airlines logo]()
$773
This Justfly.com deal was found by Cheapflights users on 9/22. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/16:50 pm -
1 stop19h 50m
Tue 10/201:50 pm -
2 stops36h 42m
Deal found 9/22![Multiple Airlines logo]()
$774
This Delta deal was found by Cheapflights users on 9/23. 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.
Tue 10/139:50 pm -
Nonstop9h 45m
Tue 10/206:30 am -
1 stop13h 22m
Deal found 9/23![Delta logo]()
$775
This FlightHub deal was found by Cheapflights users on 9/23. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/113:00 pm -
2 stops22h 00m
Sun 10/187:25 am -
1 stop17h 34m
Deal found 9/23![Multiple Airlines logo]()
$776
This Delta deal was found by Cheapflights users on 9/23. 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.
Tue 12/84:50 pm -
Nonstop9h 50m
Wed 1/136:30 am -
1 stop13h 20m
Deal found 9/23![Delta logo]()
$777
This Air Canada deal was found by Cheapflights users on 9/22. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/57:15 pm -
2 stops53h 20m
Mon 10/1210:15 am -
2 stops20h 32m
Deal found 9/22![Air Canada logo]()
$778
This Alaska Airlines deal was found by Cheapflights users on 9/23. 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.
Tue 10/139:40 pm -
Nonstop9h 25m
Mon 10/195:00 pm -
Nonstop10h 00m
Deal found 9/23![Alaska Airlines logo]()
$779
This United Airlines deal was found by Cheapflights users on 9/23. 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 12/145:05 am -
1 stop20h 35m
Fri 12/2511:35 am -
2 stops17h 05m
Deal found 9/23![United Airlines logo]()
$780
This Justfly.com deal was found by Cheapflights users on 9/22. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/3010:10 am -
2 stops16h 10m
Fri 11/69:00 am -
2 stops22h 20m
Deal found 9/22![Multiple Airlines logo]()
$781
This Air Canada deal was found by Cheapflights users on 9/24. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2010:50 am -
1 stop18h 30m
Sun 11/11:00 pm -
2 stops28h 32m
Deal found 9/24![Air Canada logo]()
$782
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 26, 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 26, 2026.
This Delta deal was found by Cheapflights users on 9/22. 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 3/145:55 pm -
1 stop15h 35m
Sun 3/285:45 pm -
Nonstop10h 18m
Deal found 9/22![Delta logo]()
$798
This Scandinavian Airlines deal was found by Cheapflights users on 9/25. 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 2/1411:45 am -
2 stops20h 15m
Sat 2/206:40 am -
2 stops23h 22m
Deal found 9/25![Scandinavian Airlines logo]()
$844
This KLM deal was found by Cheapflights users on 9/21. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/119:50 pm -
Nonstop9h 45m
Wed 10/146:30 am -
1 stop13h 22m
Deal found 9/21![KLM logo]()
$850
This United Airlines deal was found by Cheapflights users on 9/25. 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 11/93:15 pm -
1 stop12h 35m
Mon 11/1611:35 am -
1 stop14h 22m
Deal found 9/25![United Airlines logo]()
$988
This Icelandair deal was found by Cheapflights users on 9/23. 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.
Mon 11/239:37 pm -
2 stops29h 13m
Mon 1/1112:15 pm -
1 stop12h 45m
Deal found 9/23![Icelandair logo]()
$1,012
This Scandinavian Airlines deal was found by Cheapflights users on 9/24. 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 1/107:20 am -
2 stops24h 40m
Sat 1/236:40 am -
2 stops23h 22m
Deal found 9/24![Scandinavian Airlines logo]()
$845
This Delta deal was found by Cheapflights users on 9/24. 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.
Wed 1/134:55 pm -
Nonstop9h 45m
Thu 1/2811:45 am -
1 stop32h 05m
Deal found 9/24![Delta logo]()
$862
This Scandinavian Airlines deal was found by Cheapflights users on 9/22. 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 11/1512:31 pm -
2 stops21h 09m
Sun 11/226:40 am -
2 stops25h 17m
Deal found 9/22![Scandinavian Airlines logo]()
$873
This Delta deal was found by Cheapflights users on 9/26. 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.
Tue 11/34:50 pm -
Nonstop9h 50m
Sun 11/86:30 am -
1 stop13h 17m
Deal found 9/26![Delta logo]()
$948
This KLM deal was found by Cheapflights users on 9/25. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/109:50 pm -
Nonstop9h 45m
Wed 10/219:55 am -
1 stop14h 40m
Deal found 9/25![KLM logo]()
$1,049
This Delta deal was found by Cheapflights users on 9/25. 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.
Mon 11/164:50 pm -
Nonstop9h 50m
Sun 11/228:55 am -
1 stop14h 19m
Deal found 9/25![Delta logo]()
$956
This KLM deal was found by Cheapflights users on 9/24. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/215:30 pm -
Nonstop9h 50m
Sun 10/2512:20 pm -
Nonstop10h 34m
Deal found 9/24![KLM logo]()
$1,079
Last-minute flights from Seattle to HeathrowDiscover last-minute flight deals from Seattle to Heathrow. Data last updated September 26, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Heathrow. Data last updated September 26, 2026 and is based on user searches.
This Gotogate deal was found by Cheapflights users on 9/21. 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 9/2810:50 am -
2 stops17h 00m
Tue 10/1310:15 am -
2 stops16h 17m
Deal found 9/21![Air Canada logo]()
$771
This Justfly.com deal was found by Cheapflights users on 9/22. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/16:50 pm -
1 stop19h 50m
Tue 10/201:50 pm -
2 stops36h 42m
Deal found 9/22![Multiple Airlines logo]()
$774
This Delta deal was found by Cheapflights users on 9/23. 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.
Mon 10/59:50 pm -
Nonstop9h 45m
Mon 10/125:45 pm -
Nonstop10h 29m
Deal found 9/23![Delta logo]()
$777
This Air Canada deal was found by Cheapflights users on 9/22. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/57:15 pm -
2 stops53h 20m
Mon 10/1210:15 am -
2 stops20h 32m
Deal found 9/22![Air Canada logo]()
$778
This FlightHub deal was found by Cheapflights users on 9/21. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/107:15 pm -
1 stop34h 05m
Sat 10/177:10 pm -
1 stop29h 49m
Deal found 9/21![Lufthansa logo]()
$773
This FlightHub deal was found by Cheapflights users on 9/23. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/113:00 pm -
2 stops22h 00m
Sun 10/187:25 am -
1 stop17h 34m
Deal found 9/23![Multiple Airlines logo]()
$776
This United Airlines deal was found by Cheapflights users on 9/22. 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 10/126:05 pm -
1 stop31h 35m
Mon 10/266:00 pm -
1 stop33h 59m
Deal found 9/22![United Airlines logo]()
$780
This Delta deal was found by Cheapflights users on 9/23. 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.
Tue 10/139:50 pm -
Nonstop9h 45m
Tue 10/206:30 am -
1 stop13h 22m
Deal found 9/23![Delta logo]()
$775
This Alaska Airlines deal was found by Cheapflights users on 9/23. 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.
Tue 10/139:40 pm -
Nonstop9h 25m
Sat 10/245:00 pm -
Nonstop10h 00m
Deal found 9/23![Alaska Airlines logo]()
$779
This Delta deal was found by Cheapflights users on 9/21. 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.
Thu 10/159:50 pm -
Nonstop9h 45m
Thu 10/226:30 am -
1 stop18h 05m
Deal found 9/21![Delta logo]()
$772
This Air Canada deal was found by Cheapflights users on 9/24. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2010:50 am -
1 stop18h 30m
Sun 11/11:00 pm -
2 stops28h 32m
Deal found 9/24![Air Canada logo]()
$782
This FlightHub deal was found by Cheapflights users on 9/22. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/3010:10 am -
2 stops16h 10m
Fri 11/69:00 am -
2 stops22h 20m
Deal found 9/22![Multiple Airlines logo]()
$781
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 26, 2026.
Search for one-way flight options from Seattle to Heathrow. Find affordable one-way fares based on user searches. Data last updated September 26, 2026.
This Mytrip deal was found by Cheapflights users on 9/26. 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.
Sat 11/218:40 am -
2 stops20h 10m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/26![Multiple Airlines logo]()
$335
This Kiwi.com deal was found by Cheapflights users on 9/24. 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 10/63:55 pm -
3 stops33h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Multiple Airlines logo]()
$337
This Kiwi.com deal was found by Cheapflights users on 9/24. 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.
Mon 10/263:35 pm -
2 stops18h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Multiple Airlines logo]()
$338
This Mytrip deal was found by Cheapflights users on 9/23. 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 10/23:55 pm -
1 stop16h 05m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/23![Scandinavian Airlines logo]()
$340
This Kiwi.com deal was found by Cheapflights users on 9/24. 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 10/207:00 pm -
2 stops18h 40m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Multiple Airlines logo]()
$341
This Kiwi.com deal was found by Cheapflights users on 9/24. 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.
Thu 10/810:30 am -
1 stop17h 35m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![WestJet logo]()
$342
This FlightHub deal was found by Cheapflights users on 9/24. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/1810:15 pm -
1 stop27h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![JetBlue logo]()
$345
This Kiwi.com deal was found by Cheapflights users on 9/24. 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 12/252:35 pm -
1 stop20h 55m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Icelandair logo]()
$346
This Kiwi.com deal was found by Cheapflights users on 9/26. 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.
Mon 11/232:35 pm -
3 stops22h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/26![Multiple Airlines logo]()
$349
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 26, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $771 (FlightHub) |
One-way from | $335 (Mytrip) |
Popular in | June |
Cheapest in | January |
Average price | $929 |
Good round-trip deal | $841 or less |
Good one-way deal | $452 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 26, 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
Sat 1/9
8:30 am-7:10 am
3 stops38h 40m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$349
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 12/26
11:58 pm-10:15 am
1 stop26h 17m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$372
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 10/31
7:05 pm-11:50 am
1 stop33h 45m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$374
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Thu 3/18
10:10 am-11:50 am
1 stop18h 40m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$375
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 11/7
12:20 pm-8:35 pm
3 stops24h 15m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$378
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Tue 3/16
8:30 am-7:10 am
3 stops39h 40m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$423
Quickest round-trip
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Fri 10/30
7:40 pm-12:20 pm
Nonstop9h 40m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$424
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sat 10/24
6:30 pm-11:20 am
Nonstop9h 50m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$424
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sun 11/1
7:30 am-11:25 am
2 stops19h 55m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$497
SeattleLondon
SEA Seattle/Tacoma Intl - LHR London Heathrow
SEALHR
Seattle/Tacoma Intl
Sun 11/1
4:50 pm-10:40 am
Nonstop9h 50m
London Heathrow
Wed 12/31
12:00 am-3:00 pm
Nonstop0h 00m
$564
Showing 1-10 of 23 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
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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 $685). 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 26, 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 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 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
AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to London Heathrow Airport trip
Our travel experts
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 26, 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.
Crew
8.5
Comfort
7.8
Boarding
8.1
Overall
7.9
Food
7.0
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Crew
8.5
Comfort
7.8
Boarding
8.1
Overall
7.9
Food
7.0
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Crew
8.5
Comfort
7.8
Boarding
8.1
Overall
7.9
Food
7.0
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Crew
8.5
Comfort
7.8
Boarding
8.1
Overall
7.9
Food
7.0
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Crew
8.5
Comfort
7.8
Boarding
8.1
Overall
7.9
Food
7.0
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Crew
8.5
Comfort
7.8
Boarding
8.1
Overall
7.9
Food
7.0
Entertainment
7.0
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
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Basingstoke
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Northampton
Dartford
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Kingston upon Thames
Eastbourne
Slough
Stansted
Sutton
Luton
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Other flights to Heathrow
Explore flights to Heathrow departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 26, 2026.
Seattle and Heathrow flights
Browse other Seattle and Heathrow flight options. Last updated on September 26, 2026.
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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 26, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$506 | Average$726 | FlexibilityNo cancel fee | On-time76% | |
| Cheapest$535 | Average$782 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$559 | Average$986 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$560 | Average$694 | FlexibilityNo cancel fee | On-time76% | |
| Cheapest$564 | Average$993 | FlexibilityNo cancel fee | On-time72% | |
| Cheapest$584 | Average$891 | FlexibilityNo cancel fee | On-time70% | |
| Cheapest$584 | Average$842 | FlexibilityNo cancel fee | On-time77% | |
| Cheapest$595 | Average$922 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$640 | Average$992 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$648 | Average$851 | FlexibilityNo cancel fee | On-time77% |