C$ 178+ Flights from Seattle to London, ON | Cheapflights

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Cheap flight deals from Seattle to London

Round-trip from	C$ 405
One-way from	C$ 178

WestJet

WestJet
10/9-17/9
2 total stops
17h 26m total
Seattle to London

WestJet

WestJet
6/10
1 total stop
9h 02m total
Seattle to London

Find flight deals from Seattle to London

Cheapest flights from Seattle to London
Explore the most affordable flight options available from Seattle to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 29 July 2025.

Wed 10/98:40 a.m.SEA - YXU

1 stop7h 27mWestJet

Wed 17/96:00 a.m.YXU - SEA

1 stop9h 59mWestJet

Deal found 27/7C$ 405

Wed 10/97:15 p.m.SEA - YXU

2 stops11h 04mAir Canada

Wed 17/96:10 a.m.YXU - SEA

1 stop7h 49mAir Canada

Deal found 27/7C$ 469

Mon 25/811:54 p.m.SEA - YXU

2 stops12h 08mMultiple Airlines

Fri 29/86:15 a.m.YXU - SEA

2 stops11h 01mMultiple Airlines

Deal found 29/7C$ 679

Mon 29/910:54 p.m.SEA - YXU

2 stops13h 08mUnited Airlines

Fri 3/106:15 a.m.YXU - SEA

3 stops18h 00mUnited Airlines

Deal found 27/7C$ 890

Best flights from Seattle to London
Discover carefully curated flight deals from Seattle to London that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated 29 July 2025.

Wed 10/98:40 a.m.SEA - YXU

1 stop7h 27mWestJet

Wed 17/96:00 a.m.YXU - SEA

1 stop9h 59mWestJet

Deal found 27/7C$ 405

Wed 10/97:15 p.m.SEA - YXU

2 stops11h 04mAir Canada

Wed 17/96:10 a.m.YXU - SEA

1 stop7h 49mAir Canada

Deal found 27/7C$ 469

Mon 25/811:54 p.m.SEA - YXU

2 stops12h 08mMultiple Airlines

Fri 29/86:15 a.m.YXU - SEA

2 stops11h 01mMultiple Airlines

Deal found 29/7C$ 679

Mon 29/910:54 p.m.SEA - YXU

2 stops13h 08mUnited Airlines

Fri 3/106:15 a.m.YXU - SEA

3 stops18h 00mUnited Airlines

Deal found 27/7C$ 890

Last-minute flights from Seattle to London
Discover last-minute flight deals from Seattle to London. Data last updated 29 July 2025 and is based on user searches.

Mon 25/87:35 p.m.SEA - YXU

1 stop6h 39mWestJet

Fri 29/88:00 p.m.YXU - SEA

1 stop25h 55mWestJet

Deal found 29/7C$ 473

Mon 25/811:54 p.m.SEA - YXU

2 stops12h 08mMultiple Airlines

Fri 29/86:15 a.m.YXU - SEA

2 stops11h 01mMultiple Airlines

Deal found 29/7C$ 679

One-way flights from Seattle to London
Search for one-way flight options from Seattle to London. Find affordable one-way fares based on user searches. Data last updated 29 July 2025.

Mon 6/107:05 a.m.SEA - YXU

1 stop9h 02mWestJet

Deal found 27/7C$ 178

Mon 6/107:15 p.m.SEA - YXU

2 stops11h 02mAir Canada

Deal found 27/7C$ 210

Wed 20/87:35 p.m.SEA - YXU

1 stop6h 39mDelta

Deal found 27/7C$ 263

Thu 21/85:15 p.m.SEA - YXU

2 stops18h 47mUnited Airlines

Deal found 27/7C$ 298

Mon 4/85:30 p.m.SEA - YXU

3 stops48h 30mMultiple Airlines

Deal found 27/7C$ 534

Fly from

Fly to

Route

Depart

Return

Price

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 10/9

8:40 a.m.-7:07 p.m.

1 stop7h 27m

London

Wed 17/9

6:00 a.m.-12:59 p.m.

1 stop9h 59m

C$ 405

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 10/9

7:15 p.m.-9:19 a.m.

2 stops11h 04m

London

Wed 17/9

6:10 a.m.-10:59 a.m.

1 stop7h 49m

C$ 469

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 25/8

11:54 p.m.-3:02 p.m.

2 stops12h 08m

London

Fri 29/8

6:15 a.m.-2:16 p.m.

2 stops11h 01m

C$ 679

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 29/9

10:54 p.m.-3:02 p.m.

2 stops13h 08m

London

Fri 3/10

6:15 a.m.-9:15 p.m.

3 stops18h 00m

C$ 890

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 6/10

7:05 a.m.-7:07 p.m.

1 stop9h 02m

C$ 178

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 6/10

7:15 p.m.-9:17 a.m.

2 stops11h 02m

C$ 210

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 20/8

7:35 p.m.-5:14 a.m.

1 stop6h 39m

C$ 263

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 21/8

5:15 p.m.-3:02 p.m.

2 stops18h 47m

C$ 298

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 4/8

5:30 p.m.-9:00 p.m.

3 stops48h 30m

C$ 534

Flights are sorted by cheapest round-trip flights first.

Deals found on 27/7

Best time to book a flight from Seattle to London

Have a flexible travel schedule? Discover the best time to fly to London from Seattle 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 Seattle to London

What is the cheapest month to book a flight from Seattle to London, Ontario?

Currently, October is the cheapest month in which you can book a flight from Seattle to London, Ontario (average of C$ 243). Flying from Seattle to London, Ontario in December is currently the most expensive (average of C$ 478). 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 London

See what other customers who have flown with Delta,United Airlines, andWestJet from Seattle to London have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

8.0

Very good

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

8.0

Very good

8.0

Very good

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

United Airlines

7.4

Good

8.0

Very good

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

7.2

Good

8.0

Very good

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

7.1

Good

8.0

Very good

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Related info for your journey

What are the cheapest airlines flying from Seattle to London, Ontario round-trip?
WestJet, at C$ 405, was found to be the cheapest airline from Seattle to London, Ontario.Alternate airlines to your destination round-trip include Air Canada and United Airlines.
What are the cheapest airlines to fly from Seattle to London, Ontario one-way?
For one-way options, check prices for WestJet. According to our data, you can fly for as low as C$ 178. Users have also found prices from C$ 210 and C$ 263 on Air Canada and Delta, respectively.
Can I find deals for flights from Seattle to London that include hotel bookings?
Yes. In addition to deals on Seattle to London flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Seattle to London?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to London.
Can I find deals for business class flights from Seattle to London?
Yes. Cheapflights offers flight deals from Seattle to London 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 Seattle to London, Ontario?
Currently, October is the cheapest month in which you can book a flight from Seattle to London, Ontario (average of C$ 243). Flying from Seattle to London, Ontario in December is currently the most expensive (average of C$ 478). 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

Grand Bend

Port Stanley

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Complete your trip

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Need flexible booking options for your flight to London from Seattle? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

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