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Cheap flights from Seattle to London, ON from C$ 271

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 29/8. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
26 Aug — 2 Sep1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Seattle to London

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 27 July 2026.

Thu 13/87:00 a.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Sun 6/96:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 25/7C$ 585
Wed 12/87:00 a.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Sun 6/96:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 25/7C$ 586
Wed 12/87:00 a.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Mon 31/86:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 25/7C$ 602
Sat 15/87:00 a.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Thu 3/98:40 p.m.
YXU
-
SEA
1 stop16h 00m
WestJet
Deal found 25/7C$ 613
Sat 29/87:00 a.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Fri 18/95:55 p.m.
YXU
-
SEA
1 stop18h 45m
WestJet
Deal found 22/7C$ 616
Sat 15/87:00 a.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Wed 2/95:55 p.m.
YXU
-
SEA
1 stop18h 45m
WestJet
Deal found 25/7C$ 626
Wed 12/87:00 a.m.
SEA
-
YXU
1 stop6h 45m
Multiple Airlines
Tue 1/96:10 a.m.
YXU
-
SEA
2 stops32h 12m
Multiple Airlines
Deal found 25/7C$ 641
Wed 12/87:35 p.m.
SEA
-
YXU
1 stop6h 45m
Multiple Airlines
Wed 2/96:10 a.m.
YXU
-
SEA
2 stops18h 50m
Multiple Airlines
Deal found 25/7C$ 644
Sun 16/810:30 a.m.
SEA
-
YXU
1 stop15h 50m
WestJet
Sat 5/96:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 25/7C$ 647

Find 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 27 July 2026.

Round-trip from

C$ 585

One-way from

C$ 271
WestJet
  • WestJet
  • 13/8-6/9
  • 2 total stops
  • 22h 20m total
  • Seattle to London
Search Deals
WestJet
  • WestJet
  • 29/8
  • 1 total stop
  • 6h 45m 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 27 July 2026.
Use the filters below to find and compare flights from Seattle to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sat 29/8

7:00 a.m.-4:45 p.m.

1 stop6h 45m

London

Fri 18/9

5:55 p.m.-9:40 a.m.

1 stop18h 45m

C$ 616

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 6/9

7:35 p.m.-5:20 a.m.

1 stop6h 45m

London

Sun 13/9

6:10 a.m.-9:40 a.m.

1 stop30h 30m

C$ 734

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 13/8

7:00 a.m.-4:45 p.m.

1 stop6h 45m

London

Tue 1/9

6:10 a.m.-7:55 p.m.

2 stops16h 45m

C$ 891

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Tue 25/8

9:05 a.m.-9:20 a.m.

2 stops21h 15m

London

Sat 29/8

5:40 a.m.-6:29 p.m.

2 stops15h 49m

C$ 1,031
Quickest round-trip

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Tue 25/8

8:00 a.m.-5:42 p.m.

1 stop6h 42m

London

Sat 29/8

3:30 p.m.-9:07 p.m.

1 stop8h 37m

C$ 1,036

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 6/9

7:20 p.m.-9:20 a.m.

2 stops11h 00m

London

Sun 13/9

3:30 p.m.-10:47 p.m.

2 stops10h 17m

C$ 1,050

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sat 29/8

7:20 p.m.-9:20 a.m.

2 stops11h 00m

London

Fri 18/9

10:05 a.m.-6:32 p.m.

2 stops11h 27m

C$ 1,051
Cheapest one-way
Quickest one-way

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sat 29/8

7:00 a.m.-4:45 p.m.

1 stop6h 45m

C$ 271

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Fri 28/8

7:35 p.m.-5:20 a.m.

1 stop6h 45m

C$ 278

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 5/8

7:06 p.m.-7:50 p.m.

3 stops45h 44m

C$ 493

Flights are sorted by cheapest round-trip flights first.

Deals found on 22/7

Showing 1-10 of 12 resultsSorted by cheapest first
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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.

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$ 616, WestJet can have you in London, Ontario from Seattle in 6h 45m. 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.

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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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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