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Cheap flights from London, Ontario to Seattle from C$ 239

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from London, Ontario to Seattle departing on 12/10. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from London, Ontario to Seattle

Cheap round-trip flights

WestJet Logo
8:10 p.m. - 2:20 p.m.YXU-SEA
21h 10m1 stop
WestJet Logo
3:10 p.m. - 6:34 a.m.SEA-YXU
12h 24m1 stop
C$ 363WestJet
Find Deal
Mon, 8 Dec - Tue, 27 Jan
WestJet Logo
8:10 p.m. - 2:20 p.m.YXU-SEA
21h 10m1 stop
WestJet Logo
3:10 p.m. - 6:34 a.m.SEA-YXU
12h 24m1 stop
C$ 365WestJet
Find Deal
Sun, 14 Dec - Tue, 27 Jan
WestJet Logo
8:10 p.m. - 2:20 p.m.YXU-SEA
21h 10m1 stop
WestJet Logo
3:10 p.m. - 6:34 a.m.SEA-YXU
12h 24m1 stop
C$ 373WestJet
Find Deal
Sun, 7 Dec - Mon, 26 Jan
Air Canada Logo
5:45 a.m. - 2:31 p.m.YXU-SEA
11h 46m2 stops
Air Canada Logo
5:50 a.m. - 9:21 p.m.SEA-YXU
12h 31m2 stops
C$ 379Air Canada
Find Deal
Fri, 5 Dec - Tue, 27 Jan
WestJet Logo
8:10 p.m. - 10:23 a.m.YXU-SEA
17h 13m2 stops
WestJet Logo
3:10 p.m. - 6:34 a.m.SEA-YXU
12h 24m1 stop
C$ 381WestJet
Find Deal
Thu, 11 Dec - Thu, 29 Jan
Air Canada Logo
5:40 p.m. - 10:16 p.m.YXU-SEA
7h 36m1 stop
Air Canada Logo
5:50 a.m. - 9:21 p.m.SEA-YXU
12h 31m2 stops
C$ 421Air Canada
Find Deal
Wed, 3 Dec - Sun, 18 Jan
United Airlines Logo
5:40 p.m. - 10:16 p.m.YXU-SEA
7h 36m1 stop
United Airlines Logo
8:40 a.m. - 9:21 p.m.SEA-YXU
9h 41m2 stops
C$ 463United Airlines
Find Deal
Wed, 17 Dec - Sat, 31 Jan
United Airlines Logo
5:45 a.m. - 1:47 p.m.YXU-SEA
11h 02m2 stops
United Airlines Logo
5:00 a.m. - 9:21 p.m.SEA-YXU
13h 21m3 stops
C$ 470United Airlines
Find Deal
Tue, 16 Dec - Thu, 29 Jan
Multiple Airlines Logo
8:10 p.m. - 2:20 p.m.YXU-SEA
21h 10m1 stop
Multiple Airlines Logo
11:10 p.m. - 7:12 p.m.SEA-YXU
17h 02m2 stops
C$ 479Multiple Airlines
Find Deal
Mon, 17 Nov - Sun, 30 Nov
Multiple Airlines Logo
8:10 p.m. - 7:11 a.m.YXU-SEA
14h 01m2 stops
Multiple Airlines Logo
3:10 p.m. - 7:12 p.m.SEA-YXU
25h 02m1 stop
C$ 482Multiple Airlines
Find Deal
Tue, 18 Nov - Sun, 30 Nov

WestJet flights from London, Ontario to Seattle

Our best WestJet deals on London, Ontario to Seattle flight tickets
WestJet
8 Dec
YXU8:10 p.m.London
21h 10m
1 stop
SEA2:20 p.m.Seattle/Tacoma Intl
27 Jan
SEA3:10 p.m.Seattle/Tacoma Intl
12h 24m
1 stop
YXU6:34 a.m.London
C$ 363
Find similar
WestJet
14 Dec
YXU8:10 p.m.London
21h 10m
1 stop
SEA2:20 p.m.Seattle/Tacoma Intl
27 Jan
SEA3:10 p.m.Seattle/Tacoma Intl
12h 24m
1 stop
YXU6:34 a.m.London
C$ 365
Find similar
WestJet
7 Dec
YXU8:10 p.m.London
21h 10m
1 stop
SEA2:20 p.m.Seattle/Tacoma Intl
26 Jan
SEA3:10 p.m.Seattle/Tacoma Intl
12h 24m
1 stop
YXU6:34 a.m.London
C$ 373
Find similar

Air Canada flights from London, Ontario to Seattle

Our best Air Canada deals on London, Ontario to Seattle flight tickets
Air Canada
5 Dec
YXU5:45 a.m.London
11h 46m
2 stops
SEA2:31 p.m.Seattle/Tacoma Intl
27 Jan
SEA5:50 a.m.Seattle/Tacoma Intl
12h 31m
2 stops
YXU9:21 p.m.London
C$ 379
Find similar
Air Canada
3 Dec
YXU5:40 p.m.London
7h 36m
1 stop
SEA10:16 p.m.Seattle/Tacoma Intl
18 Jan
SEA5:50 a.m.Seattle/Tacoma Intl
12h 31m
2 stops
YXU9:21 p.m.London
C$ 421
Find similar
Air Canada
15 Dec
YXU5:40 p.m.London
7h 36m
1 stop
SEA10:16 p.m.Seattle/Tacoma Intl
9 Feb
SEA8:15 a.m.Seattle/Tacoma Intl
10h 06m
1 stop
YXU9:21 p.m.London
C$ 428
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from London, Ontario 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, momondo users made 96,600 searches. Data last updated 16 September 2025.
Use the filters below to find and compare flights from London, Ontario to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 8/12

8:10 p.m.-2:20 p.m.

1 stop21h 10m

Seattle/Tacoma Intl

Tue 27/1

3:10 p.m.-6:34 a.m.

1 stop12h 24m

C$ 363

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 14/12

8:10 p.m.-2:20 p.m.

1 stop21h 10m

Seattle/Tacoma Intl

Tue 27/1

3:10 p.m.-6:34 a.m.

1 stop12h 24m

C$ 365

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 7/12

8:10 p.m.-2:20 p.m.

1 stop21h 10m

Seattle/Tacoma Intl

Mon 26/1

3:10 p.m.-6:34 a.m.

1 stop12h 24m

C$ 373

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 5/12

5:45 a.m.-2:31 p.m.

2 stops11h 46m

Seattle/Tacoma Intl

Tue 27/1

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

2 stops12h 31m

C$ 379

LondonSeattle

YXU - SEA

YXUSEA

London

Thu 11/12

8:10 p.m.-10:23 a.m.

2 stops17h 13m

Seattle/Tacoma Intl

Thu 29/1

3:10 p.m.-6:34 a.m.

1 stop12h 24m

C$ 381

LondonSeattle

YXU - SEA

YXUSEA

London

Wed 3/12

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

1 stop7h 36m

Seattle/Tacoma Intl

Sun 18/1

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

2 stops12h 31m

C$ 421

LondonSeattle

YXU - SEA

YXUSEA

London

Wed 17/12

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

1 stop7h 36m

Seattle/Tacoma Intl

Sat 31/1

8:40 a.m.-9:21 p.m.

2 stops9h 41m

C$ 463

LondonSeattle

YXU - SEA

YXUSEA

London

Tue 16/12

5:45 a.m.-1:47 p.m.

2 stops11h 02m

Seattle/Tacoma Intl

Thu 29/1

5:00 a.m.-9:21 p.m.

3 stops13h 21m

C$ 470

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 17/11

8:10 p.m.-2:20 p.m.

1 stop21h 10m

Seattle/Tacoma Intl

Sun 30/11

11:10 p.m.-7:12 p.m.

2 stops17h 02m

C$ 479

LondonSeattle

YXU - SEA

YXUSEA

London

Tue 18/11

8:10 p.m.-7:11 a.m.

2 stops14h 01m

Seattle/Tacoma Intl

Sun 30/11

3:10 p.m.-7:12 p.m.

1 stop25h 02m

C$ 482

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Seattle from

How to get the cheapest flight ticket from London, Ontario to Seattle

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest day to depart on your flight to Seattle?

Our data shows that Friday is the least expensive day to fly to Seattle. Tickets to fly out on this day can be as low as C$ 370. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around C$ 704. These prices are subject to change though, so be sure to set up a Price Alert for flights to Seattle.

What is the cheapest time of day to depart on your flight to Seattle?

Our most recent data shows that the best time of day to fly to Seattle is in the afternoon. Flights from London, Ontario to Seattle during this time can be as low as C$ 557. Flights in the morning are often more expensive with an average ticket price of C$ 566.

When to book flights from London, Ontario to Seattle

Are you open to changing your travel dates? Check out the ideal times to fly from London, Ontario to Seattle according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap London, Ontario to Seattle (YXU to SEA) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from London, Ontario to Seattle

Direct flights

None
There are no direct flights from London, Ontario to Seattle. There are no popular flight routes from London, Ontario to Seattle.
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  • How far is London to Seattle/Tacoma Intl by plane?

    The distance between London and Seattle/Tacoma Intl is about 3215.2 km. By plane, this route typically takes 7h 36m.

  • When did momondo last update prices for flights from London Airport to Seattle/Tacoma Intl Airport?

    Prices for flights from London Airport to Seattle/Tacoma Intl Airport were last updated today.

  • How many operators does momondo search for flights from London Airport to Seattle/Tacoma Intl Airport?

  • How old do you have to be to fly from London Airport to Seattle/Tacoma Intl Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from London Airport to Seattle/Tacoma Intl Airport.

  • What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

    The necessary travel and health documents for your Seattle/Tacoma Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from London, Ontario to Seattle?

Best airlines flying from London, Ontario to Seattle

Compare and see reviews for airlines that fly from London, Ontario to Seattle with momondo
Airline
Rating
Free Cancellation
Price
WestJetPriceFrom C$ 242Free CancellationRating
7.2
3,093 reviews
Search WestJet flights
United AirlinesPriceFrom C$ 278Free CancellationRating
7.4
8,924 reviews
Search United Airlines flights
Air CanadaPriceFrom C$ 369Free CancellationRating
7.1
10,000 reviews
Search Air Canada flights

Travelling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Leavenworth
Lynnwood
Marysville
Tacoma
SeaTac
Kirkland
Redmond
Olympia
Ocean Shores
Shoreline
Ellensburg
Gig Harbor
Renton
Mukilteo
Cle Elum
Poulsbo
Federal Way
Puyallup
Kent
Shelton

Why use momondo?

Why should I use momondo to find a flight deal from London to Seattle?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from London to Seattle . Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from London to Seattle with flexible booking policies on momondo?

Flights from London to Seattle with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from London to Seattle?

Once you have performed a search for London to Seattle flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from London to Seattle right now. Can momondo alert me if prices change?

Of course. momondo tracks the price of London to Seattle flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

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