What is the cheapest airline that flies from London to Seattle/Tacoma Intl?

Air Canada, WestJet, and United Airlines are the most popular carriers operating from London to Seattle/Tacoma Intl

What airlines fly to Seattle?

Alaska Airlines, Air Canada and WestJet are the top three most popular airlines that fly to Seattle from London, Ontario according to our data. Alaska Airlines is the first choice among our users, with 36% of people opting to fly with this airline when traveling to Seattle. Keep in mind that there are 6 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.

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 are updated daily.

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 that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check 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.

$173 Cheap Flights from London to Seattle in 2025/26

1 adult

0 bags

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

Find the cheapest flights from London, Ontario to Seattle

Round-trip

One-way

Cheap round-trip flights

8:10 pm - 2:20 pmYXU-SEA

21h 10m1 stop

3:10 pm - 6:34 amSEA-YXU

12h 24m1 stop

$263WestJet

Find Deal

Mon, Dec 8 - Tue, Jan 27

8:10 pm - 2:20 pmYXU-SEA

21h 10m1 stop

3:10 pm - 6:34 amSEA-YXU

12h 24m1 stop

$264WestJet

Find Deal

Sun, Dec 14 - Tue, Jan 27

8:10 pm - 2:20 pmYXU-SEA

21h 10m1 stop

3:10 pm - 6:34 amSEA-YXU

12h 24m1 stop

$270WestJet

Find Deal

Sun, Dec 7 - Tue, Jan 27

5:45 am - 2:31 pmYXU-SEA

11h 46m2 stops

5:50 am - 9:21 pmSEA-YXU

12h 31m2 stops

$274Air Canada

Find Deal

Fri, Dec 5 - Tue, Jan 27

8:10 pm - 10:23 amYXU-SEA

17h 13m2 stops

3:10 pm - 6:34 amSEA-YXU

12h 24m1 stop

$276WestJet

Find Deal

Thu, Dec 11 - Thu, Jan 29

5:40 pm - 10:16 pmYXU-SEA

7h 36m1 stop

5:50 am - 9:21 pmSEA-YXU

12h 31m2 stops

$305Air Canada

Find Deal

Wed, Dec 3 - Sun, Jan 18

5:40 pm - 10:16 pmYXU-SEA

7h 36m1 stop

12:40 pm - 5:05 pmSEA-YXU

25h 25m3 stops

$335United Airlines

Find Deal

Wed, Dec 17 - Thu, Jan 29

5:45 am - 1:47 pmYXU-SEA

11h 02m2 stops

5:00 am - 9:21 pmSEA-YXU

13h 21m3 stops

$340United Airlines

Find Deal

Tue, Dec 16 - Thu, Jan 29

8:10 pm - 2:20 pmYXU-SEA

21h 10m1 stop

11:10 pm - 7:12 pmSEA-YXU

17h 02m2 stops

$347Multiple Airlines

Find Deal

Mon, Nov 17 - Sun, Nov 30

8:10 pm - 7:11 amYXU-SEA

14h 01m2 stops

3:10 pm - 7:12 pmSEA-YXU

25h 02m1 stop

$349Multiple Airlines

Find Deal

Tue, Nov 18 - Sun, Nov 30

WestJet flights from London, Ontario to Seattle

Our best WestJet deals on London, Ontario to Seattle flight tickets

WestJet

Dec 8

YXU8:10 pmLondon

21h 10m

1 stop

SEA2:20 pmSeattle/Tacoma Intl

Jan 27

SEA3:10 pmSeattle/Tacoma Intl

12h 24m

1 stop

YXU6:34 amLondon

$263

Find similar

WestJet

Dec 14

YXU8:10 pmLondon

21h 10m

1 stop

SEA2:20 pmSeattle/Tacoma Intl

Jan 27

SEA3:10 pmSeattle/Tacoma Intl

12h 24m

1 stop

YXU6:34 amLondon

$264

Find similar

WestJet

Dec 7

YXU8:10 pmLondon

21h 10m

1 stop

SEA2:20 pmSeattle/Tacoma Intl

Jan 27

SEA3:10 pmSeattle/Tacoma Intl

12h 24m

1 stop

YXU6:34 amLondon

$270

Find similar

Air Canada flights from London, Ontario to Seattle

Our best Air Canada deals on London, Ontario to Seattle flight tickets

Air Canada

Dec 5

YXU5:45 amLondon

11h 46m

2 stops

SEA2:31 pmSeattle/Tacoma Intl

Jan 27

SEA5:50 amSeattle/Tacoma Intl

12h 31m

2 stops

YXU9:21 pmLondon

$274

Find similar

Air Canada

Dec 3

YXU5:40 pmLondon

7h 36m

1 stop

SEA10:16 pmSeattle/Tacoma Intl

Jan 18

SEA5:50 amSeattle/Tacoma Intl

12h 31m

2 stops

YXU9:21 pmLondon

$305

Find similar

Air Canada

Dec 15

YXU5:40 pmLondon

7h 36m

1 stop

SEA10:16 pmSeattle/Tacoma Intl

Feb 13

SEA8:15 amSeattle/Tacoma Intl

10h 06m

1 stop

YXU9:21 pmLondon

$310

Find similar

Fly from

Fly to

Route

Depart

Return

Price

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 12/8

8:10 pm-2:20 pm

1 stop21h 10m

Seattle/Tacoma Intl

Tue 1/27

3:10 pm-6:34 am

1 stop12h 24m

$263

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 12/14

8:10 pm-2:20 pm

1 stop21h 10m

Seattle/Tacoma Intl

Tue 1/27

3:10 pm-6:34 am

1 stop12h 24m

$264

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 12/7

8:10 pm-2:20 pm

1 stop21h 10m

Seattle/Tacoma Intl

Tue 1/27

3:10 pm-6:34 am

1 stop12h 24m

$270

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 12/5

5:45 am-2:31 pm

2 stops11h 46m

Seattle/Tacoma Intl

Tue 1/27

5:50 am-9:21 pm

2 stops12h 31m

$274

LondonSeattle

YXU - SEA

YXUSEA

London

Thu 12/11

8:10 pm-10:23 am

2 stops17h 13m

Seattle/Tacoma Intl

Thu 1/29

3:10 pm-6:34 am

1 stop12h 24m

$276

LondonSeattle

YXU - SEA

YXUSEA

London

Wed 12/3

5:40 pm-10:16 pm

1 stop7h 36m

Seattle/Tacoma Intl

Sun 1/18

5:50 am-9:21 pm

2 stops12h 31m

$305

LondonSeattle

YXU - SEA

YXUSEA

London

Wed 12/17

5:40 pm-10:16 pm

1 stop7h 36m

Seattle/Tacoma Intl

Thu 1/29

12:40 pm-5:05 pm

3 stops25h 25m

$335

LondonSeattle

YXU - SEA

YXUSEA

London

Tue 12/16

5:45 am-1:47 pm

2 stops11h 02m

Seattle/Tacoma Intl

Thu 1/29

5:00 am-9:21 pm

3 stops13h 21m

$340

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 11/17

8:10 pm-2:20 pm

1 stop21h 10m

Seattle/Tacoma Intl

Sun 11/30

11:10 pm-7:12 pm

2 stops17h 02m

$347

LondonSeattle

YXU - SEA

YXUSEA

London

Tue 11/18

8:10 pm-7:11 am

2 stops14h 01m

Seattle/Tacoma Intl

Sun 11/30

3:10 pm-7:12 pm

1 stop25h 02m

$349

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

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

Prices

Airlines

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

On average, the least expensive day to fly to Seattle from London, Ontario is on a Saturday. momondo users have found tickets for Saturday departures for as low as $316. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Monday is the most expensive day to depart from London, Ontario because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $449.

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

Flying to Seattle from London, Ontario in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $330 when looking at flights departing in the afternoon. Flights to Seattle are more costly in the morning, with an average ticket price of $477. Departure times in the morning fall within the peak daily travel times, which is why tickets can be more expensive.

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.

Search flight deals

How far is London to Seattle/Tacoma Intl by plane?
Seattle/Tacoma Intl is 1997.9 mi away from London. Flights usually cover this in 7h 36m, depending on flying conditions and air traffic around both airports.
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 are updated daily.
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 that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check 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.

Leavenworth

Tacoma

SeaTac

Ocean Shores

Renton

Olympia

Lynnwood

Kent

Marysville

Puyallup

Federal Way

Kirkland

Tukwila

Shoreline

Lakewood

Centralia

Fife

Cle Elum

Redmond

Westport

Why use momondo?

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

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Seattle from London.

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

momondo does allow users to show only those flights to Seattle from London which offer a flexible booking policy as well as other useful filters and features.

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

momondo provides multiple filters to help you find the best flight to Seattle from London. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

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

If you are simply researching potential flights to Seattle, momondo offers a useful price alert feature which will track prices for flights to Seattle from London and alert you when they change.