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$385+ Cheap flights from London, ON (YXU) to Seattle (SEA)

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 3/2. Fares are subject to change and may not be available on all flights or dates of travel.
YXU — SEA
Jan 11 — Jan 181
Sun 1/11
Sun 1/18
1 adult, Economy
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Cheap flight deals from London to Seattle

Best flights from London to Seattle
Discover carefully curated flight deals from London to Seattle that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated December 12, 2025.

This WestJet deal was found by Cheapflights users on 12/9. 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.
Mon 3/28:10 pmYXU - SEA
1 stop21h 09mWestJet
Wed 3/43:10 pmSEA - YXU
1 stop12h 25mWestJet
Deal found 12/9$385
This Air Canada deal was found by Cheapflights users on 12/9. 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 3/29:25 amYXU - SEA
2 stops12h 51mAir Canada
Wed 3/48:00 pmSEA - YXU
2 stops9h 46mAir Canada
Deal found 12/9$437
This KAYAK deal was found by Cheapflights users on 12/11. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/235:10 amYXU - SEA
3 stops18h 51mUnited Airlines
Thu 2/265:00 amSEA - YXU
2 stops9h 05mUnited Airlines
Deal found 12/11$765
This KAYAK deal was found by Cheapflights users on 12/11. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/238:10 pmYXU - SEA
1 stop21h 09mWestJet
Thu 2/263:10 pmSEA - YXU
1 stop12h 25mWestJet
Deal found 12/11$385
This KAYAK deal was found by Cheapflights users on 12/11. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/235:40 pmYXU - SEA
1 stop7h 36mAir Canada
Thu 2/268:00 pmSEA - YXU
2 stops9h 46mAir Canada
Deal found 12/11$498
This United Airlines deal was found by Cheapflights users on 12/10. 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 3/25:10 amYXU - SEA
3 stops16h 16mUnited Airlines
Wed 3/46:04 pmSEA - YXU
2 stops11h 42mUnited Airlines
Deal found 12/10$1,129

Find 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 December 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$385
(WestJet)
Provider with most accurate pricing for London-Seattle/Tacoma Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for London-Seattle/Tacoma Intl flights.
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From London to Seattle/Tacoma Intl
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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 2,558,603 searches. Data last updated December 12, 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

Mon 3/2

8:10 pm-2:19 pm

1 stop21h 09m

Seattle/Tacoma Intl

Wed 3/4

3:10 pm-6:35 am

1 stop12h 25m

$385

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 2/23

8:10 pm-2:19 pm

1 stop21h 09m

Seattle/Tacoma Intl

Thu 2/26

3:10 pm-6:35 am

1 stop12h 25m

$385

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 3/2

9:25 am-7:16 pm

2 stops12h 51m

Seattle/Tacoma Intl

Wed 3/4

8:00 pm-8:46 am

2 stops9h 46m

$437

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 2/23

5:40 pm-10:16 pm

1 stop7h 36m

Seattle/Tacoma Intl

Thu 2/26

8:00 pm-8:46 am

2 stops9h 46m

$498

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 2/23

5:10 am-9:01 pm

3 stops18h 51m

Seattle/Tacoma Intl

Thu 2/26

5:00 am-5:05 pm

2 stops9h 05m

$765

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 3/2

5:10 am-6:26 pm

3 stops16h 16m

Seattle/Tacoma Intl

Wed 3/4

6:04 pm-8:46 am

2 stops11h 42m

$1,129

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/9

Compare providers for flights from London to Seattle

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 London to Seattle in December.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on London, Ontario-Seattle flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on London, Ontario-Seattle flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from London, Ontario-Seattle flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on London, Ontario-Seattle flights, Cheapflights users trust eDreams the most. eDreams 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 London, Ontario-Seattle 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 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

What is the cheapest month to book a flight from London, Ontario to Seattle?

Currently, December is the cheapest month in which you can book a flight from London, Ontario to Seattle (average of $131). Flying from London, Ontario to Seattle in June is currently the most expensive (average of $249). 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 December 12, 2025.

Unlike at noon, when flights are generally more expensive, you can save up to 31% on flights from London, Ontario to Seattle by exploring options for tickets in the afternoon.

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.

  • How long is the flight from London, Ontario to Seattle?

    Departing from London, Ontario to Seattle will take you 12h 51m. There are 2000 mi between London, Ontario and Seattle. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • Can I find deals for flights from London to Seattle that include hotel bookings?

    Yes. In addition to deals on London to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from London to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from London to Seattle.

  • Can I find deals for business class flights from London to Seattle?

    Yes. Cheapflights offers flight deals from London to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from London, Ontario to Seattle?

    Currently, December is the cheapest month in which you can book a flight from London, Ontario to Seattle (average of $131). Flying from London, Ontario to Seattle in June is currently the most expensive (average of $249). 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.

See more FAQs

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Tacoma
SeaTac
Lakewood
Olympia
Ocean Shores
Edmonds
Lynnwood
Renton
Puyallup
Kirkland
Tukwila
Kent
Cle Elum
Marysville
Leavenworth
Fife
Aberdeen
Shoreline
Centralia
Federal Way

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