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Cheap flights from Seattle to London, ON from C$ 222

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 26/10. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
11 Oct — 18 Oct1
1 adult
1 adult, Economy

Cheap flight deals from Seattle to London

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to London (YXU). 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 11 September 2025.

Round-trip from

C$ 552

One-way from

C$ 222
Air Canada
  • Air Canada
  • 19/10-22/10
  • 2 total stops
  • 20h 02m total
  • Seattle to London
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WestJet
  • WestJet
  • 26/10
  • 2 total stops
  • 28h 17m total
  • Seattle to London
Search Deals

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 11 September 2025.

Sun 19/107:30 a.m.SEA - YXU
1 stop10h 57mAir Canada
Wed 22/103:40 p.m.YXU - SEA
1 stop9h 05mAir Canada
Deal found 11/9C$ 552
Sun 19/1010:54 p.m.SEA - YXU
2 stops13h 08mMultiple Airlines
Wed 22/106:15 a.m.YXU - SEA
2 stops11h 01mMultiple Airlines
Deal found 11/9C$ 658
Sun 19/1010:54 p.m.SEA - YXU
2 stops13h 08mUnited Airlines
Wed 22/106:15 a.m.YXU - SEA
3 stops20h 00mUnited Airlines
Deal found 11/9C$ 680
Thu 25/98:40 a.m.SEA - YXU
1 stop17h 32mWestJet
Sun 28/98:00 p.m.YXU - SEA
1 stop27h 29mWestJet
Deal found 11/9C$ 782
Mon 22/128:00 p.m.SEA - YXU
2 stops9h 46mAir Canada
Mon 29/125:40 p.m.YXU - SEA
1 stop7h 36mAir Canada
Deal found 10/9C$ 825
Sun 26/1011:59 p.m.SEA - YXU
2 stops14h 07mUnited Airlines
Sun 2/115:40 p.m.YXU - SEA
1 stop7h 36mUnited Airlines
Deal found 11/9C$ 874
Sun 26/1011:55 a.m.SEA - YXU
2 stops28h 17mWestJet
Sun 2/118:00 p.m.YXU - SEA
1 stop21h 20mWestJet
Deal found 11/9C$ 1,092

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to London 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 11 September 2025.
Use the filters below to find and compare flights from Seattle to London that are best for you.

Fly from

Seattle

Fly to

London

Route

Depart

Return

Price

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 19/10

7:30 a.m.-9:27 p.m.

1 stop10h 57m

London

Wed 22/10

3:40 p.m.-9:45 p.m.

1 stop9h 05m

C$ 552

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 19/10

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

2 stops13h 08m

London

Wed 22/10

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

2 stops11h 01m

C$ 658

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 19/10

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

2 stops13h 08m

London

Wed 22/10

6:15 a.m.-11:15 p.m.

3 stops20h 00m

C$ 680

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 22/12

8:00 p.m.-8:46 a.m.

2 stops9h 46m

London

Mon 29/12

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

1 stop7h 36m

C$ 825

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 25/9

8:40 a.m.-5:12 a.m.

1 stop17h 32m

London

Sun 28/9

6:00 a.m.-7:00 p.m.

2 stops40h 00m

C$ 843

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 26/10

11:59 p.m.-5:06 p.m.

2 stops14h 07m

London

Sun 2/11

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

1 stop7h 36m

C$ 874

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 26/10

11:55 a.m.-7:12 p.m.

2 stops28h 17m

London

Sun 2/11

8:00 p.m.-2:20 p.m.

1 stop21h 20m

C$ 1,092

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 26/10

11:55 a.m.-7:12 p.m.

2 stops28h 17m

C$ 222

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 26/10

3:36 p.m.-7:12 p.m.

1 stop24h 36m

C$ 270

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 21/9

3:36 p.m.-5:12 a.m.

1 stop10h 36m

C$ 497

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/9

Showing 1-10 of 11 results
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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.

Related info for your journey

Find useful and relevant information for your journey from Seattle to London. 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 Seattle to London, Ontario?

    For as low as C$ 552, Air Canada can have you in London, Ontario from Seattle in 10h 57m. The distance between Seattle and London, Ontario is about 3219 km. This flight may include one or multiple stops.

  • 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

Travelling to a place near London?

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

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Can Cheapflights find flights from Seattle to London with no change fees?

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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