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Cheap flights from London, ON to Seattle from C$ 215

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 15/2. Fares are subject to change and may not be available on all flights or dates of travel.
YXU — SEA
26 Feb — 5 Mar1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from London to Seattle

Enter your travel dates to find the best prices.

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 27 January 2026.

Wed 11/38:10 p.m.
YXU
-
SEA
1 stop21h 09m
WestJet
Sun 15/311:55 a.m.
SEA
-
YXU
2 stops15h 40m
WestJet
Deal found 25/1C$ 518
Sat 2/56:15 a.m.
YXU
-
SEA
2 stops9h 28m
Multiple Airlines
Sat 9/57:35 p.m.
SEA
-
YXU
1 stop6h 50m
Multiple Airlines
Deal found 27/1C$ 571
Sat 2/56:15 a.m.
YXU
-
SEA
1 stop15h 30m
WestJet
Sat 9/57:35 p.m.
SEA
-
YXU
1 stop6h 50m
WestJet
Deal found 26/1C$ 608
Sun 8/38:10 p.m.
YXU
-
SEA
2 stops17h 15m
WestJet
Wed 11/33:10 p.m.
SEA
-
YXU
1 stop12h 25m
WestJet
Deal found 26/1C$ 656
Sun 8/35:10 a.m.
YXU
-
SEA
2 stops12h 51m
Air Canada
Wed 11/38:00 p.m.
SEA
-
YXU
2 stops9h 46m
Air Canada
Deal found 26/1C$ 745
Sat 2/512:20 p.m.
YXU
-
SEA
2 stops9h 10m
Air Canada
Sat 9/55:40 a.m.
SEA
-
YXU
2 stops12h 58m
Air Canada
Deal found 26/1C$ 757

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 27 January 2026.

Round-trip from

C$ 518

One-way from

C$ 215

Popular in

March

Cheapest in

May

Average price

C$ 566
WestJet
  • WestJet
  • 11/3-15/3
  • 3 total stops
  • 36h 49m total
  • London to Seattle
Search Deals
Air Canada
  • Air Canada
  • 15/2
  • 1 total stop
  • 7h 36m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 22% potential increase in price (C$ 177 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 11% potential price decrease (C$ 62 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
Search Deals

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 27 January 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

Wed 11/3

8:10 p.m.-2:19 p.m.

1 stop21h 09m

Seattle/Tacoma Intl

Sun 15/3

11:55 a.m.-6:35 a.m.

2 stops15h 40m

C$ 518

LondonSeattle

YXU - SEA

YXUSEA

London

Sat 2/5

6:15 a.m.-12:43 p.m.

2 stops9h 28m

Seattle/Tacoma Intl

Sat 9/5

7:35 p.m.-5:25 a.m.

1 stop6h 50m

C$ 571

LondonSeattle

YXU - SEA

YXUSEA

London

Sat 2/5

6:15 a.m.-6:45 p.m.

1 stop15h 30m

Seattle/Tacoma Intl

Sat 9/5

7:35 p.m.-5:25 a.m.

1 stop6h 50m

C$ 608

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 8/3

8:10 p.m.-10:25 a.m.

2 stops17h 15m

Seattle/Tacoma Intl

Wed 11/3

3:10 p.m.-6:35 a.m.

1 stop12h 25m

C$ 656

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 8/3

5:10 a.m.-2:01 p.m.

2 stops12h 51m

Seattle/Tacoma Intl

Wed 11/3

5:50 a.m.-9:21 p.m.

2 stops12h 31m

C$ 772

LondonSeattle

YXU - SEA

YXUSEA

London

Wed 17/6

6:00 a.m.-10:20 a.m.

1 stop7h 20m

Seattle/Tacoma Intl

Thu 25/6

11:30 a.m.-9:37 p.m.

1 stop7h 07m

C$ 826

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 9/2

5:40 p.m.-10:16 p.m.

1 stop7h 36m

C$ 219

LondonSeattle

YXU - SEA

YXUSEA

London

Sat 13/6

5:55 p.m.-6:45 p.m.

1 stop27h 50m

C$ 348

LondonSeattle

YXU - SEA

YXUSEA

London

Wed 17/6

5:55 p.m.-6:50 a.m.

1 stop15h 55m

C$ 414

LondonSeattle

YXU - SEA

YXUSEA

London

Sat 13/6

5:55 p.m.-7:07 a.m.

2 stops16h 12m

C$ 416

Flights are sorted by cheapest round-trip flights first.

Deals found on 25/1

Showing 1-10 of 16 results
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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 C$ 179). Flying from London, Ontario to Seattle in August is currently the most expensive (average of C$ 305). 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.

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 27 January 2026.
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.
United Airlines
7.4
Good
9,205 reviews
Check prices

Food

6.6

Boarding

7.7

Overall

7.4

Comfort

7.3

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats
United Airlines
7.4
Good
9,205 reviews
United Airlines
7.4
Good
9,205 reviews
Check prices

Food

6.6

Boarding

7.7

Overall

7.4

Comfort

7.3

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats
WestJet
7.2
Good
3,251 reviews
United Airlines
7.4
Good
9,205 reviews
Check prices

Food

6.6

Boarding

7.7

Overall

7.4

Comfort

7.3

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats
Air Canada
7.1
Good
10,660 reviews
United Airlines
7.4
Good
9,205 reviews
Check prices

Food

6.6

Boarding

7.7

Overall

7.4

Comfort

7.3

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats

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. The distance between London, Ontario and Seattle is about 3219 km.

  • What are the cheapest airlines flying from London, Ontario to Seattle round-trip?

    According to our current data, WestJet (C$ 240), United Airlines (C$ 275), and Air Canada (C$ 366) offers the cheapest pricing from London, Ontario to Seattle. WestJet is 46% cheaper than the average price of flights available within the next 90 days to this destination.

  • 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 C$ 179). Flying from London, Ontario to Seattle in August is currently the most expensive (average of C$ 305). 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

Travelling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Leavenworth
SeaTac
Mukilteo
Tacoma
Kent
Tukwila
Bothell
Cashmere
Olympia
Renton
Lynnwood
Marysville
Kirkland

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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.
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Kingston to Seattle flights

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 27 January 2026.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 240AverageC$ 403FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 275AverageC$ 292FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Air CanadaCheapestC$ 366AverageC$ 446FlexibilityNo cancel feeOn-time67%
Search Air Canada flights

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.

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