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Cheap flights from Seattle to London from $367

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to London departing on 4/9. 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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0 bags

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Find the cheapest flights from Seattle to London

Cheap round-trip flights

Enter your travel dates to find the best prices.
WestJet Logo
3:10 pm - 6:35 am
SEA
-
YXU
12h 25m
1 stop
WestJet Logo
8:10 pm - 10:25 am
YXU
-
SEA
17h 15m
2 stops
$367WestJet
Thu, Apr 9 - Thu, Apr 16
WestJet Logo
7:35 pm - 5:20 am
SEA
-
YXU
6h 45m
1 stop
WestJet Logo
5:55 pm - 6:45 pm
YXU
-
SEA
27h 50m
1 stop
$391WestJet
Wed, Jul 22 - Sun, Jul 26
Air Canada Logo
7:20 pm - 8:55 am
SEA
-
YXU
10h 35m
2 stops
Air Canada Logo
3:30 pm - 9:07 pm
YXU
-
SEA
8h 37m
1 stop
$452Air Canada
Wed, Jul 22 - Sun, Jul 26
Air Canada Logo
5:40 am - 9:18 pm
SEA
-
YXU
12h 38m
2 stops
Air Canada Logo
9:25 am - 7:20 pm
YXU
-
SEA
12h 55m
2 stops
$461Air Canada
Thu, Apr 9 - Thu, Apr 16
Multiple Airlines Logo
10:09 am - 6:35 am
SEA
-
YXU
17h 26m
2 stops
Multiple Airlines Logo
8:10 pm - 2:19 pm
YXU
-
SEA
21h 09m
1 stop
$463Multiple Airlines
Wed, Apr 8 - Wed, Apr 15
WestJet Logo
3:10 pm - 6:35 am
SEA
-
YXU
12h 25m
1 stop
WestJet Logo
8:10 pm - 2:19 pm
YXU
-
SEA
21h 09m
1 stop
$472WestJet
Wed, Apr 8 - Wed, Apr 15
Air Canada Logo
5:40 am - 9:21 pm
SEA
-
YXU
12h 41m
2 stops
Air Canada Logo
9:40 am - 9:53 pm
YXU
-
SEA
15h 13m
1 stop
$480Air Canada
Thu, Mar 26 - Mon, Mar 30
Air Canada Logo
7:20 pm - 8:55 am
SEA
-
YXU
10h 35m
2 stops
Air Canada Logo
6:10 pm - 9:17 am
YXU
-
SEA
18h 07m
2 stops
$484Air Canada
Wed, Jul 22 - Sun, Jul 26
Multiple Airlines Logo
3:10 pm - 6:35 am
SEA
-
YXU
12h 25m
1 stop
Multiple Airlines Logo
8:10 pm - 7:51 pm
YXU
-
SEA
26h 41m
1 stop
$496Multiple Airlines
Thu, Apr 9 - Thu, Apr 16
Air Canada Logo
8:00 am - 9:21 pm
SEA
-
YXU
10h 21m
1 stop
Air Canada Logo
9:40 am - 9:53 pm
YXU
-
SEA
15h 13m
1 stop
$500Air Canada
Thu, Mar 26 - Mon, Mar 30

Air Canada flights from Seattle to London, Ontario

Our best Air Canada deals on Seattle to London, Ontario flight tickets
Air Canada
Jul 22
SEA7:20 pmSeattle/Tacoma Intl
10h 35m
2 stops
YXU8:55 amLondon
Jul 26
YXU3:30 pmLondon
8h 37m
1 stop
SEA9:07 pmSeattle/Tacoma Intl
$452
Air Canada
Apr 9
SEA5:40 amSeattle/Tacoma Intl
12h 38m
2 stops
YXU9:18 pmLondon
Apr 16
YXU9:25 amLondon
12h 55m
2 stops
SEA7:20 pmSeattle/Tacoma Intl
$461
Air Canada
Mar 26
SEA5:40 amSeattle/Tacoma Intl
12h 41m
2 stops
YXU9:21 pmLondon
Mar 30
YXU9:40 amLondon
15h 13m
1 stop
SEA9:53 pmSeattle/Tacoma Intl
$480

United Airlines flights from Seattle to London, Ontario

Our best United Airlines deals on Seattle to London, Ontario flight tickets
United Airlines
Mar 5
SEA5:00 amSeattle/Tacoma Intl
13h 21m
2 stops
YXU9:21 pmLondon
Mar 8
YXU5:40 pmLondon
7h 36m
1 stop
SEA10:16 pmSeattle/Tacoma Intl
$814
United Airlines
Mar 5
SEA5:00 amSeattle/Tacoma Intl
13h 21m
2 stops
YXU9:21 pmLondon
Mar 8
YXU5:10 amLondon
18h 48m
3 stops
SEA7:58 pmSeattle/Tacoma Intl
$1,093
United Airlines
Mar 5
SEA5:00 amSeattle/Tacoma Intl
13h 21m
2 stops
YXU9:21 pmLondon
Mar 8
YXU5:10 amLondon
18h 48m
3 stops
SEA7:58 pmSeattle/Tacoma Intl
$1,133

momondo Fare Finder

 
Customize your flight search to find flights from Seattle to London, Ontario 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 832,500 searches. Data last updated February 25, 2026.
Use the filters below to find and compare flights from Seattle to London, Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 4/9

3:10 pm-6:35 am

1 stop12h 25m

London

Thu 4/16

8:10 pm-10:25 am

2 stops17h 15m

$367

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 7/22

7:35 pm-5:20 am

1 stop6h 45m

London

Sun 7/26

5:55 pm-6:45 pm

1 stop27h 50m

$391

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 7/22

7:20 pm-8:55 am

2 stops10h 35m

London

Sun 7/26

3:30 pm-9:07 pm

1 stop8h 37m

$452

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 4/9

5:40 am-9:18 pm

2 stops12h 38m

London

Thu 4/16

9:25 am-7:20 pm

2 stops12h 55m

$461

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 4/8

10:09 am-6:35 am

2 stops17h 26m

London

Wed 4/15

8:10 pm-2:19 pm

1 stop21h 09m

$463

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 4/8

3:10 pm-6:35 am

1 stop12h 25m

London

Wed 4/15

8:10 pm-2:19 pm

1 stop21h 09m

$472

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 3/26

5:40 am-9:21 pm

2 stops12h 41m

London

Mon 3/30

9:40 am-9:53 pm

1 stop15h 13m

$480

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 7/22

7:20 pm-8:55 am

2 stops10h 35m

London

Sun 7/26

6:10 pm-9:17 am

2 stops18h 07m

$484

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 4/9

3:10 pm-6:35 am

1 stop12h 25m

London

Thu 4/16

8:10 pm-7:51 pm

1 stop26h 41m

$496

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 3/26

8:00 am-9:21 pm

1 stop10h 21m

London

Mon 3/30

9:40 am-9:53 pm

1 stop15h 13m

$500

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

See travel insights to London from

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

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

Can stopping save me money on Seattle to London, Ontario flights?

You could potentially save up to 49% on your flight if you consider stops on a Seattle to London, Ontario flight.

When to book flights from Seattle to London, Ontario

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

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

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

Fastest flight time

12h 25m

Direct flights

None
The fastest flight from Seattle to London, Ontario takes 12h 25m
There are no direct flights from Seattle to London, Ontario. There are no popular flight routes from Seattle to London, Ontario.
Search flight deals

  • How far is Seattle/Tacoma Intl to London by plane?

    The straight-line distance from Seattle/Tacoma Intl to London is 1997.9 mi. By plane, this route typically takes 12h 25m.

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

    Prices for flights from Seattle/Tacoma Intl Airport to London Airport are updated daily.

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

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

  • What documentation or ID do you need to fly to London Airport?

    The travel and health documents you'll need for your trip to London Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at London Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

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

Best airlines flying from Seattle to London, Ontario

Compare and see reviews for airlines that fly from Seattle to London, Ontario with momondo
Airline
Rating
Free Cancellation
Price
Air CanadaPriceFrom $460Free CancellationRating
7.1
10,745 reviews
Search Air Canada flights

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Grand Bend
Port Stanley

Why use momondo?

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

Finding the right flight to London from Seattle is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to London quick and easy, saving you time and money.

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

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

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

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Seattle to London.

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

Yes. momondo can track prices for Seattle to London flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

An easier way to manage your London, Ontario trip

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