$247+ Cheap flights from Seattle (SEA) to London, ON (YXU)
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 12/2. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
Oct 24 — Oct 311
Round-trip
1 adult, Economy
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Find cheap flights from Seattle to London 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.Cheap flight deals from Seattle to London
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Cheapest flights from Seattle to LondonExplore the most affordable flight options available from Seattle to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 24, 2026.
Explore the most affordable flight options available from Seattle to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 24, 2026.
This Trip.com 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/52:30 pm -
1 stop12h 05m
Thu 11/126:40 am -
1 stop10h 00m
Deal found 9/21![WestJet logo]()
$495
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/227:35 pm -
1 stop6h 45m
Wed 10/287:40 am -
2 stops13h 51m
Deal found 9/21![Multiple Airlines logo]()
$500
This WestJet deal was found by Cheapflights users on 9/20. 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 WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/207:35 pm -
1 stop6h 45m
Sat 10/246:10 am -
1 stop15h 35m
Deal found 9/20![WestJet logo]()
$515
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/58:15 am -
2 stops18h 20m
Thu 11/126:40 am -
1 stop10h 00m
Deal found 9/21![Multiple Airlines logo]()
$576
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.
Sun 12/272:30 pm -
1 stop12h 05m
Tue 1/56:40 am -
1 stop10h 00m
Deal found 9/21![WestJet logo]()
$582
This FlightHub deal was found by Cheapflights users on 9/20. 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 12/202:30 pm -
1 stop12h 05m
Wed 12/306:40 am -
1 stop10h 00m
Deal found 9/20![WestJet logo]()
$625
Best flights from Seattle to LondonDiscover carefully curated flight deals from Seattle to London that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 24, 2026.
Discover carefully curated flight deals from Seattle to London that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 24, 2026.
This Trip.com 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/52:30 pm -
1 stop12h 05m
Thu 11/126:40 am -
1 stop10h 00m
Deal found 9/21![WestJet logo]()
$495
This Mytrip 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/59:13 pm -
3 stops29h 22m
Thu 11/126:40 am -
1 stop10h 00m
Deal found 9/21![Multiple Airlines logo]()
$661
This United Airlines 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/207:25 pm -
2 stops21h 15m
Sat 10/243:30 pm -
1 stop9h 09m
Deal found 9/21![United Airlines logo]()
$835
This Air Canada deal was found by Cheapflights users on 9/20. 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 10/207:55 am -
1 stop8h 45m
Sat 10/249:05 am -
2 stops12h 27m
Deal found 9/20![Air Canada logo]()
$837
This WestJet deal was found by Cheapflights users on 9/20. 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 WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/207:35 pm -
1 stop6h 45m
Sat 10/246:10 am -
1 stop15h 35m
Deal found 9/20![WestJet logo]()
$515
This Kiwi.com deal was found by Cheapflights users on 9/20. 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 12/202:30 pm -
1 stop12h 05m
Wed 12/306:40 am -
2 stops19h 33m
Deal found 9/20![Multiple Airlines logo]()
$782
Last-minute flights from Seattle to LondonDiscover last-minute flight deals from Seattle to London. Data last updated September 24, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to London. Data last updated September 24, 2026 and is based on user searches.
This WestJet 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 WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/187:35 pm -
1 stop6h 45m
Fri 10/307:40 am -
1 stop10h 00m
Deal found 9/23![WestJet logo]()
$742
This WestJet deal was found by Cheapflights users on 9/20. 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 WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/207:35 pm -
1 stop6h 45m
Sat 10/246:10 am -
1 stop15h 35m
Deal found 9/20![WestJet logo]()
$515
This United Airlines 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/207:25 pm -
2 stops21h 15m
Sat 10/243:30 pm -
1 stop9h 09m
Deal found 9/21![United Airlines logo]()
$835
This Air Canada deal was found by Cheapflights users on 9/19. 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 10/207:55 am -
1 stop8h 45m
Sat 10/249:05 am -
2 stops12h 27m
Deal found 9/19![Air Canada logo]()
$837
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/227:35 pm -
1 stop6h 45m
Wed 10/287:40 am -
2 stops13h 51m
Deal found 9/21![Multiple Airlines logo]()
$500
One-way flights from Seattle to LondonSearch for one-way flight options from Seattle to London. Find affordable one-way fares based on user searches. Data last updated September 24, 2026.
Search for one-way flight options from Seattle to London. Find affordable one-way fares based on user searches. Data last updated September 24, 2026.
This Expedia deal was found by Cheapflights users on 9/20. 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.
Wed 12/22:30 pm -
1 stop12h 05m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/20![WestJet logo]()
$247
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/79:39 pm -
3 stops28h 56m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/23![Multiple Airlines logo]()
$339
This Kiwi.com deal was found by Cheapflights users on 9/20. 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.
Wed 12/29:34 pm -
2 stops29h 01m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/20![Multiple Airlines logo]()
$349
This Air Canada 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/77:45 am -
1 stop11h 12m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/23![Air Canada logo]()
$436
Find flight deals from Seattle to London
Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to London (YXU). 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 24, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $495 (Trip.com) |
One-way from | $247 (Expedia) |
Cheapflights Fare Finder
Customize your flight search to find flights from Seattle to London 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 24, 2026.
Use the filters below to find and compare flights from Seattle to London that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Wed 12/2
2:30 pm-5:35 am
1 stop12h 05m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$247
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Wed 12/2
9:34 pm-5:35 am
2 stops29h 01m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$349
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Sat 11/7
9:39 pm-5:35 am
2 stops28h 56m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$354
Quickest round-trip
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Sat 11/7
7:45 am-9:57 pm
1 stop11h 12m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$436
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Thu 11/5
2:30 pm-5:35 am
1 stop12h 05m
London
Thu 11/12
6:40 am-1:40 pm
1 stop10h 00m
$495
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Tue 10/20
7:35 pm-5:20 am
1 stop6h 45m
London
Sat 10/24
6:10 am-6:45 pm
1 stop15h 35m
$515
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Thu 11/5
9:13 pm-5:35 am
3 stops29h 22m
London
Thu 11/12
6:40 am-1:40 pm
1 stop10h 00m
$661
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Sun 12/20
2:30 pm-5:35 am
1 stop12h 05m
London
Wed 12/30
6:40 am-11:13 pm
2 stops19h 33m
$782
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Tue 10/20
7:25 pm-7:40 pm
2 stops21h 15m
London
Sat 10/24
3:30 pm-9:39 pm
1 stop9h 09m
$835
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Tue 10/20
7:55 am-7:40 pm
1 stop8h 45m
London
Sat 10/24
9:05 am-6:32 pm
2 stops12h 27m
$837
Sorted by cheapest first
- Most accurate provider: When it comes to deals on Seattle-London, Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-London, Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-London, Ontario flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Seattle-London, Ontario 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, Ontario 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 London
Have a flexible travel schedule? Discover the best time to fly to London from Seattle with our price prediction graph.
SEA-YXU
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.
Related info for your journey
Find useful and relevant information for your journey from Seattle to London. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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