$355+ 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 12/20. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
Nov 7 — Nov 141
Round-trip
1 adult, Economy
We work with more than 300 partners to bring you better travel deals
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
Cheapest
Best
Last-minute
One-way
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 October 8, 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 October 8, 2026.
This Expedia deal was found by Cheapflights users on 10/5. 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.
Thu 11/192:30 pm -
1 stop12h 05m
Thu 11/266:40 am -
1 stop10h 00m
Deal found 10/5![WestJet logo]()
$544
This WestJet deal was found by Cheapflights users on 10/6. 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 10/6![WestJet logo]()
$667
This Mytrip deal was found by Cheapflights users on 10/5. 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 11/192:30 pm -
1 stop12h 05m
Thu 11/2610:00 am -
2 stops32h 22m
Deal found 10/5![Multiple Airlines logo]()
$689
This FlightHub deal was found by Cheapflights users on 10/4. 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 10/4![WestJet logo]()
$712
This Air Canada deal was found by Cheapflights users on 10/4. 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.
Fri 12/187:45 am -
1 stop11h 07m
Sun 1/33:20 pm -
1 stop8h 39m
Deal found 10/4![Air Canada logo]()
$952
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 October 8, 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 October 8, 2026.
This WestJet deal was found by Cheapflights users on 10/6. 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 10/6![WestJet logo]()
$667
This Mytrip deal was found by Cheapflights users on 10/5. 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 11/199:13 pm -
3 stops29h 22m
Thu 11/266:40 am -
1 stop10h 00m
Deal found 10/5![Multiple Airlines logo]()
$696
This Delta deal was found by Cheapflights users on 10/6. 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 3/151:40 pm -
2 stops13h 55m
Wed 3/317:40 am -
1 stop10h 00m
Deal found 10/6![Delta logo]()
$834
This FlightHub deal was found by Cheapflights users on 10/4. 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 10/4![WestJet logo]()
$712
This Delta deal was found by Cheapflights users on 10/6. 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 3/1612:00 pm -
2 stops15h 35m
Wed 3/317:40 am -
1 stop10h 00m
Deal found 10/6![Delta logo]()
$907
Last-minute flights from Seattle to LondonDiscover last-minute flight deals from Seattle to London. Data last updated October 8, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to London. Data last updated October 8, 2026 and is based on user searches.
This WestJet deal was found by Cheapflights users on 10/6. 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 10/6![WestJet logo]()
$667
This Air Canada deal was found by Cheapflights users on 10/3. 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 10/3![Air Canada logo]()
$1,055
This Expedia deal was found by Cheapflights users on 10/5. 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.
Thu 11/192:30 pm -
1 stop12h 05m
Thu 11/266:40 am -
1 stop10h 00m
Deal found 10/5![WestJet logo]()
$544
This Mytrip deal was found by Cheapflights users on 10/5. 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 11/192:30 pm -
1 stop12h 05m
Thu 11/2610:00 am -
2 stops32h 22m
Deal found 10/5![Multiple Airlines logo]()
$689
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 October 8, 2026.
Search for one-way flight options from Seattle to London. Find affordable one-way fares based on user searches. Data last updated October 8, 2026.
This Expedia deal was found by Cheapflights users on 10/4. 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 12/202:30 pm -
1 stop12h 05m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/4![WestJet logo]()
$355
This Air Canada deal was found by Cheapflights users on 10/4. 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.
Fri 12/187:45 am -
1 stop11h 07m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/4![Air Canada logo]()
$467
This WestJet deal was found by Cheapflights users on 10/6. 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.
Fri 10/167:35 pm -
1 stop6h 45m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/6![WestJet logo]()
$472
This Air Canada deal was found by Cheapflights users on 10/6. 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.
Fri 10/165:50 am -
2 stops10h 50m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/6![Air Canada logo]()
$498
This Air Canada deal was found by Cheapflights users on 10/4. 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 12/193:15 pm -
2 stops14h 22m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/4![Air Canada logo]()
$535
This United Airlines deal was found by Cheapflights users on 10/4. 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.
Fri 12/1810:55 am -
2 stops18h 42m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/4![United Airlines logo]()
$541
This United Airlines deal was found by Cheapflights users on 10/6. 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.
Sat 10/177:00 am -
2 stops9h 40m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/6![United Airlines logo]()
$612
This Kiwi.com deal was found by Cheapflights users on 10/4. 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 12/195:25 pm -
3 stops33h 10m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/4![Multiple Airlines logo]()
$617
This United Airlines deal was found by Cheapflights users on 10/6. 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.
Fri 10/168:30 am -
3 stops27h 20m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/6![United Airlines logo]()
$681
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 October 8, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $544 (Expedia) |
One-way from | $355 (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 October 8, 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
Quickest round-trip
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Sat 10/17
7:35 pm-5:20 am
1 stop6h 45m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$472
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Fri 10/16
5:50 am-7:40 pm
2 stops10h 50m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$498
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Sun 12/20
2:10 pm-8:37 am
2 stops15h 27m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$541
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Fri 12/18
10:55 am-8:37 am
2 stops18h 42m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$541
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Sat 10/17
7:00 am-7:40 pm
2 stops9h 40m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$612
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Sun 12/20
11:00 am-5:35 am
3 stops15h 35m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$616
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
$667
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Fri 10/16
8:30 am-2:50 pm
3 stops27h 20m
London
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$681
SeattleLondon
SEA Seattle/Tacoma Intl - YXU London
SEAYXU
Seattle/Tacoma Intl
Thu 11/19
9:13 pm-5:35 am
3 stops29h 22m
London
Thu 11/26
6:40 am-1:40 pm
1 stop10h 00m
$696
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-1:40 pm
1 stop10h 00m
$712
Showing 1-10 of 12 resultsSorted 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.
Browse thousands of different options on Cheapflights for your next trip
Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.
Alternative routes
Complete your trip
Flights by cabin class
London flight routes
Other flight options
Other flights from Seattle
Popular flights