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$157+ Cheap flights from London, ON (YXU) to Seattle (SEA)

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 2/15. Fares are subject to change and may not be available on all flights or dates of travel.
YXU — SEA
Feb 28 — Mar 71
Sat 2/28
Sat 3/7
1 adult, Economy
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Cheap flight deals from London to Seattle

Cheapest flights from London to Seattle
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 January 29, 2026.

This FlightHub deal was found by Cheapflights users on 1/27. 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 5/26:15 am
YXU
-
SEA
2 stops9h 28m
Multiple Airlines
Sat 5/97:35 pm
SEA
-
YXU
1 stop6h 50m
Multiple Airlines
Deal found 1/27$417
This WestJet deal was found by Cheapflights users on 1/28. 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 3/88:10 pm
YXU
-
SEA
1 stop21h 09m
WestJet
Wed 3/113:10 pm
SEA
-
YXU
1 stop12h 25m
WestJet
Deal found 1/28$424
This FlightHub deal was found by Cheapflights users on 1/28. 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 5/26:15 am
YXU
-
SEA
2 stops28h 20m
WestJet
Sat 5/97:35 pm
SEA
-
YXU
1 stop6h 50m
WestJet
Deal found 1/28$433
This Air Canada deal was found by Cheapflights users on 1/26. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/85:10 am
YXU
-
SEA
2 stops12h 51m
Air Canada
Wed 3/118:00 pm
SEA
-
YXU
2 stops9h 46m
Air Canada
Deal found 1/26$544
This Air Canada deal was found by Cheapflights users on 1/27. 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 5/212:20 pm
YXU
-
SEA
2 stops13h 00m
Air Canada
Sat 5/95:40 am
SEA
-
YXU
2 stops8h 53m
Air Canada
Deal found 1/27$561

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 January 29, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$417
(FlightHub)

One-way from

$157
(Air Canada)

Popular in

March

Cheapest in

May

Average price

$413
Provider with most accurate pricing for London-Seattle/Tacoma Intl flight deals.
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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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One-way flight from London to Seattle/Tacoma Intl
Search Deals
Highest demand for flights based on searches. 22% potential increase in price ($95 potential increase over avg. RT price).
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Cheapest flight prices on average. 10% potential price decrease ($33 potential savings vs. average RT price).
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Average for round-trip flights in January 2026
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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 January 29, 2026.
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

Sat 5/2

6:15 am-12:43 pm

2 stops9h 28m

Seattle/Tacoma Intl

Sat 5/9

7:35 pm-5:25 am

1 stop6h 50m

$417

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 3/8

8:10 pm-2:19 pm

1 stop21h 09m

Seattle/Tacoma Intl

Wed 3/11

3:10 pm-6:35 am

1 stop12h 25m

$424

LondonSeattle

YXU - SEA

YXUSEA

London

Sat 5/2

6:15 am-7:35 am

2 stops28h 20m

Seattle/Tacoma Intl

Sat 5/9

7:35 pm-5:25 am

1 stop6h 50m

$433

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 3/8

5:10 am-2:01 pm

2 stops12h 51m

Seattle/Tacoma Intl

Wed 3/11

8:00 pm-8:46 am

2 stops9h 46m

$545

LondonSeattle

YXU - SEA

YXUSEA

London

Wed 6/17

6:00 am-10:20 am

1 stop7h 20m

Seattle/Tacoma Intl

Thu 6/25

11:30 am-9:37 pm

1 stop7h 07m

$603

LondonSeattle

YXU - SEA

YXUSEA

London

Sat 6/13

5:55 pm-6:45 pm

1 stop27h 50m

$254

LondonSeattle

YXU - SEA

YXUSEA

London

Tue 6/16

6:15 am-9:00 pm

1 stop17h 45m

$254

LondonSeattle

YXU - SEA

YXUSEA

London

Wed 6/17

5:55 pm-6:50 am

1 stop15h 55m

$302

LondonSeattle

YXU - SEA

YXUSEA

London

Sat 6/13

5:55 pm-7:07 am

2 stops16h 12m

$304

LondonSeattle

YXU - SEA

YXUSEA

London

Wed 6/17

5:55 pm-7:31 am

2 stops16h 36m

$316

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/27

Showing 1-10 of 13 results
1
2
  • Most accurate provider: When it comes to deals on London, Ontario-Seattle flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on London, Ontario-Seattle flight deals on Cheapflights vs. FlightHub >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 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 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 August is currently the most expensive (average of $223). 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.

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 21h 09m. There are 2000 mi between London, Ontario and Seattle.

  • 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 August is currently the most expensive (average of $223). 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
Ocean Shores
Olympia
Lynnwood
Lacey
Edmonds
Renton
Puyallup
Kirkland
Kent
Tukwila
Fife
Aberdeen
Shoreline
Marysville
Centralia
Federal Way
Chehalis

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