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Cheap flights from London, ON to Seattle from C$ 237
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 26/10. Fares are subject to change and may not be available on all flights or dates of travel.
YXU — SEA
11 Oct — 18 Oct1
Cheap flight deals from London to Seattle
Discover tips and strategies to find the most affordable flight options for your journey from London (YXU) to Seattle (SEA). 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 11 September 2025.
Find flight deals from London to Seattle
Cheapest flights from London to SeattleExplore the most affordable flight options available from London to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 11 September 2025.
Explore the most affordable flight options available from London to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 11 September 2025.
Wed 22/106:00 a.m.YXU - SEA
1 stop9h 59mWestJet
Tue 11/113:10 p.m.SEA - YXU
1 stop25h 02mWestJet
Deal found 11/9C$ 410
Sat 25/106:00 a.m.YXU - SEA
1 stop9h 59mWestJet
Tue 11/113:10 p.m.SEA - YXU
1 stop25h 02mWestJet
Deal found 11/9C$ 432
Wed 22/106:00 a.m.YXU - SEA
1 stop9h 59mWestJet
Wed 12/113:10 p.m.SEA - YXU
1 stop25h 02mWestJet
Deal found 11/9C$ 442
Fri 24/108:00 p.m.YXU - SEA
1 stop19h 59mWestJet
Thu 13/113:10 p.m.SEA - YXU
1 stop25h 02mWestJet
Deal found 11/9C$ 445
Sat 25/106:00 a.m.YXU - SEA
1 stop9h 59mWestJet
Wed 12/113:10 p.m.SEA - YXU
1 stop25h 02mWestJet
Deal found 11/9C$ 461
Wed 22/106:00 a.m.YXU - SEA
1 stop9h 59mMultiple Airlines
Wed 12/1111:10 p.m.SEA - YXU
2 stops17h 02mMultiple Airlines
Deal found 11/9C$ 475
Wed 22/106:00 a.m.YXU - SEA
1 stop9h 59mMultiple Airlines
Thu 13/1111:10 p.m.SEA - YXU
2 stops17h 02mMultiple Airlines
Deal found 11/9C$ 493
Sat 25/106:00 a.m.YXU - SEA
1 stop9h 59mMultiple Airlines
Tue 11/1111:10 p.m.SEA - YXU
2 stops17h 02mMultiple Airlines
Deal found 11/9C$ 496
Mon 20/108:00 p.m.YXU - SEA
1 stop19h 59mWestJet
Thu 13/113:10 p.m.SEA - YXU
1 stop25h 02mWestJet
Deal found 11/9C$ 500
Wed 22/106:00 a.m.YXU - SEA
1 stop9h 59mWestJet
Mon 10/1111:55 a.m.SEA - YXU
2 stops28h 17mWestJet
Deal found 11/9C$ 506
Fri 24/108:00 p.m.YXU - SEA
1 stop19h 59mMultiple Airlines
Wed 12/1111:10 p.m.SEA - YXU
2 stops17h 02mMultiple Airlines
Deal found 11/9C$ 510
Sat 25/106:00 a.m.YXU - SEA
1 stop9h 59mMultiple Airlines
Thu 13/1111:10 p.m.SEA - YXU
2 stops17h 02mMultiple Airlines
Deal found 11/9C$ 513
Cheapflights Fare Finder
Customize your flight search to find flights from London to Seattle 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 629,999 searches. Data last updated 11 September 2025.
Use the filters below to find and compare flights from London to Seattle that are best for you.
Fly from
London
Fly to
Seattle
Route
Depart
Return
Price
LondonSeattle
YXU - SEA
YXUSEA
London
Thu 23/10
6:00 a.m.-12:59 p.m.
1 stop9h 59m
Seattle/Tacoma Intl
Tue 11/11
3:10 p.m.-7:12 p.m.
1 stop25h 02m
C$ 410
LondonSeattle
YXU - SEA
YXUSEA
London
Sat 25/10
6:00 a.m.-12:59 p.m.
1 stop9h 59m
Seattle/Tacoma Intl
Thu 13/11
3:10 p.m.-7:12 p.m.
1 stop25h 02m
C$ 432
LondonSeattle
YXU - SEA
YXUSEA
London
Wed 22/10
6:00 a.m.-12:59 p.m.
1 stop9h 59m
Seattle/Tacoma Intl
Wed 12/11
3:10 p.m.-7:12 p.m.
1 stop25h 02m
C$ 442
LondonSeattle
YXU - SEA
YXUSEA
London
Sat 25/10
6:15 a.m.-2:16 p.m.
2 stops11h 01m
Seattle/Tacoma Intl
Sat 1/11
8:00 p.m.-9:46 a.m.
2 stops10h 46m
C$ 445
LondonSeattle
YXU - SEA
YXUSEA
London
Fri 24/10
8:00 p.m.-12:59 p.m.
1 stop19h 59m
Seattle/Tacoma Intl
Wed 12/11
3:10 p.m.-7:12 p.m.
1 stop25h 02m
C$ 475
LondonSeattle
YXU - SEA
YXUSEA
London
Thu 23/10
6:00 a.m.-12:59 p.m.
1 stop9h 59m
Seattle/Tacoma Intl
Thu 13/11
11:10 p.m.-7:12 p.m.
2 stops17h 02m
C$ 493
LondonSeattle
YXU - SEA
YXUSEA
London
Mon 20/10
8:00 p.m.-12:59 p.m.
1 stop19h 59m
Seattle/Tacoma Intl
Thu 13/11
3:10 p.m.-7:12 p.m.
1 stop25h 02m
C$ 500
LondonSeattle
YXU - SEA
YXUSEA
London
Mon 20/10
8:00 p.m.-12:59 p.m.
1 stop19h 59m
Seattle/Tacoma Intl
Tue 11/11
3:10 p.m.-7:12 p.m.
1 stop25h 02m
C$ 500
LondonSeattle
YXU - SEA
YXUSEA
London
Fri 24/10
8:00 p.m.-12:59 p.m.
1 stop19h 59m
Seattle/Tacoma Intl
Wed 12/11
11:10 p.m.-7:12 p.m.
2 stops17h 02m
C$ 510
LondonSeattle
YXU - SEA
YXUSEA
London
Fri 24/10
3:40 p.m.-9:45 p.m.
1 stop9h 05m
Seattle/Tacoma Intl
Thu 13/11
5:50 a.m.-9:21 p.m.
2 stops12h 31m
C$ 518
Showing 1-10 of 18 results
Best time to book a flight from London to Seattle
Have a flexible travel schedule? Discover the best time to fly to Seattle from London with our price prediction graph.
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 London to Seattle
Prices
More
What is the cheapest month to book a flight from London, Ontario to Seattle?
Currently, January is the cheapest month in which you can book a flight from London, Ontario to Seattle (average of C$ 262). Flying from London, Ontario to Seattle in December is currently the most expensive (average of C$ 353). 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 YXU to SEA?
Find hourly flight availability from London to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 11 September 2025.
One of the essential ways to save on airfare from London, Ontario to Seattle is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight at noon could potentially save you up to 2% on airfare.
What’s the top layover airport for flights from London, Ontario to Seattle?
Share of one-stop round-trip flights from London, Ontario to Seattle chosen by Cheapflights users in the past 12 months, using the same layover each way.
Calgary (YYC) – chosen by Cheapflights users on 94% of one-stop itineraries from London, Ontario to Seattle on Cheapflights.
What’s the fastest layover option from London, Ontario to Seattle?
Shortest average travel time for 1-stop one-way flights from London, Ontario to Seattle, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.
Flights via Toronto (YYZ) have the shortest average one-way travel time for 1-stop routes: 7h 46m.
What’s the fastest layover option from London, Ontario to Seattle?
Shortest average travel time for 1-stop one-way flights from London, Ontario to Seattle, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.
Flights via Toronto (YYZ) have the shortest average one-way travel time for 1-stop routes: 7h 46m.
Which airport typically offers the quickest layover for flights from London, Ontario to Seattle?
Average layover duration for 1-stop one-way flights from London, Ontario to Seattle, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.
Flights via Toronto (YYZ) offer the fastest connection on this route, with an average layover time of 1h 38m.
Reviews of airlines servicing Seattle
Get insights into the airlines that provide service to Seattle. 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 Seattle. Reviews last updated 11 September 2025.
Read through reviews of airlines operating flights from London to Seattle, such as United Airlines,WestJet, andAir Canada. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Crew
8.1
Boarding
7.7
Entertainment
7.1
Overall
7.4
Food
6.6
Comfort
7.3
Reviews
1 / 20
10.0
ExcellentAnonymous,Sep 2025
FRA - SFO
Crew
8.1
Boarding
7.7
Entertainment
7.1
Overall
7.4
Food
6.6
Comfort
7.3
Reviews
1 / 20
10.0
ExcellentAnonymous,Sep 2025
FRA - SFO
Crew
8.1
Boarding
7.7
Entertainment
7.1
Overall
7.4
Food
6.6
Comfort
7.3
Reviews
1 / 20
10.0
ExcellentAnonymous,Sep 2025
FRA - SFO
Crew
8.1
Boarding
7.7
Entertainment
7.1
Overall
7.4
Food
6.6
Comfort
7.3
Reviews
1 / 20
10.0
ExcellentAnonymous,Sep 2025
FRA - SFO
Related info for your journey
Find useful and relevant information for your journey from London to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Travelling to a place near Seattle?
Book flights to Seattle if you plan to visit one of these locationsLeavenworth
SeaTac
Tukwila
Tacoma
Bothell
Cashmere
Renton
Olympia
Marysville
Lynnwood
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Alternative routes for London to Seattle
See prices for flight routes from nearby airports that may be better suited for you.
Top 3 airlines flying from London to Seattle
Discover the top 3 airlines that operate flights from London to Seattle. 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 629,999 searches. Data last updated 11 September 2025.
Fly with Cheapflights
Find the best flight deals on Cheapflights, where travelers can enjoy low prices and a wide availability of flights to their desired destinations.
How does Cheapflights help users find flights from London to Seattle?
900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Seattle from London today with Cheapflights!
Why should you use Cheapflights to find cheap flight tickets from London to Seattle?
Cheapflights helps you find that perfect flight to Seattle from London by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!
Can Cheapflights find flights from London to Seattle with no change fees?
Certainly. Search results for flights to Seattle from London shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.
Can Cheapflights notify me if prices for flights from London to Seattle become cheaper?
Yes, Cheapflights offers price alerts on London to Seattle flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.