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Cheap flights from Seattle to London, ON from C$ 396

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 2/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
27 Nov — 4 Dec1
1 adult
1 adult, Economy, 0 bags

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Enter your travel dates to find the best prices.

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 28 October 2025.

Thu 11/128:00 p.m.SEA - YXU
2 stops9h 46mAir Canada
Thu 18/125:40 p.m.YXU - SEA
1 stop7h 36mAir Canada
Deal found 27/10C$ 656
Thu 11/123:10 p.m.SEA - YXU
1 stop12h 24mMultiple Airlines
Thu 18/125:40 p.m.YXU - SEA
1 stop7h 36mMultiple Airlines
Deal found 27/10C$ 691
Thu 20/113:10 p.m.SEA - YXU
1 stop25h 02mWestJet
Mon 24/118:10 p.m.YXU - SEA
1 stop21h 10mWestJet
Deal found 27/10C$ 799
Thu 20/113:10 p.m.SEA - YXU
1 stop25h 02mMultiple Airlines
Mon 24/118:10 p.m.YXU - SEA
2 stops24h 05mMultiple Airlines
Deal found 27/10C$ 804
Fri 12/128:00 p.m.SEA - YXU
2 stops9h 46mAir Canada
Fri 19/129:25 a.m.YXU - SEA
1 stop15h 51mAir Canada
Deal found 28/10C$ 871
Tue 25/115:05 a.m.SEA - YXU
2 stops9h 00mUnited Airlines
Tue 2/125:40 p.m.YXU - SEA
1 stop7h 36mUnited Airlines
Deal found 28/10C$ 929
Thu 11/125:00 a.m.SEA - YXU
2 stops9h 05mUnited Airlines
Thu 18/125:10 a.m.YXU - SEA
3 stops20h 49mUnited Airlines
Deal found 27/10C$ 957

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 28 October 2025.

Round-trip from

C$ 396
Air Canada
  • Air Canada
  • 2/3-4/3
  • 3 total stops
  • 17h 22m total
  • Seattle to London
Search Deals

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 28 October 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

Mon 2/3

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

2 stops9h 46m

London

Wed 4/3

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

1 stop7h 36m

C$ 396

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 2/3

7:00 a.m.-9:21 p.m.

2 stops11h 21m

London

Wed 4/3

5:15 a.m.-6:03 p.m.

3 stops15h 48m

C$ 551

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 11/12

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

2 stops9h 46m

London

Thu 18/12

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

1 stop7h 36m

C$ 656

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 11/12

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

1 stop12h 24m

London

Thu 18/12

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

1 stop7h 36m

C$ 691

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 20/11

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

1 stop25h 02m

London

Mon 24/11

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

1 stop21h 10m

C$ 799

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Fri 12/12

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

2 stops9h 46m

London

Fri 19/12

9:25 a.m.-10:16 p.m.

1 stop15h 51m

C$ 871

Flights are sorted by cheapest round-trip flights first.

Deals found on 26/10

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, March is the cheapest month in which you can book a flight from Seattle to London, Ontario (average of C$ 169). Flying from Seattle to London, Ontario in May is currently the most expensive (average of C$ 379). 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$ 396, Air Canada can have you in London, Ontario from Seattle in 9h 46m. The distance between Seattle and London, Ontario is about 3219 km.

  • 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, March is the cheapest month in which you can book a flight from Seattle to London, Ontario (average of C$ 169). Flying from Seattle to London, Ontario in May is currently the most expensive (average of C$ 379). 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
Port Stanley
Grand Bend

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