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Cheap flights from Seattle to London, ON from C$ 303

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 6/8. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
12 Jul — 19 Jul1
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 12 June 2026.

Sun 19/77:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Sun 26/75:55 p.m.
YXU
-
SEA
1 stop30h 05m
WestJet
Deal found 7/6C$ 619
Wed 23/97:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Wed 7/106:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 12/6C$ 641
Tue 22/97:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Wed 7/106:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 9/6C$ 645
Thu 6/87:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Mon 10/85:55 p.m.
YXU
-
SEA
1 stop18h 45m
WestJet
Deal found 8/6C$ 648
Mon 21/97:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Thu 8/106:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 9/6C$ 686
Wed 8/77:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Tue 14/75:55 p.m.
YXU
-
SEA
1 stop18h 45m
WestJet
Deal found 11/6C$ 715
Wed 14/107:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Thu 15/105:55 p.m.
YXU
-
SEA
1 stop18h 45m
WestJet
Deal found 9/6C$ 761
Sat 19/97:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Wed 7/106:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 9/6C$ 772

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 12 June 2026.

Round-trip from

C$ 619

One-way from

C$ 303
WestJet
  • WestJet
  • 19/7-26/7
  • 2 total stops
  • 36h 50m total
  • Seattle to London
Search Deals
WestJet
  • WestJet
  • 6/8
  • 1 total stop
  • 27h 15m 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 12 June 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

Tue 22/9

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

1 stop6h 45m

London

Wed 7/10

6:10 a.m.-6:45 p.m.

1 stop15h 35m

C$ 650

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 8/7

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

1 stop6h 45m

London

Tue 14/7

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

1 stop18h 45m

C$ 715

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Fri 25/9

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

1 stop6h 45m

London

Mon 28/9

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

1 stop18h 45m

C$ 761

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 14/10

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

1 stop6h 45m

London

Thu 15/10

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

1 stop18h 45m

C$ 761

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 20/9

5:20 p.m.-9:20 a.m.

2 stops13h 00m

London

Mon 5/10

3:30 p.m.-9:04 p.m.

1 stop8h 34m

C$ 839

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sat 19/9

7:00 a.m.-9:40 p.m.

2 stops11h 40m

London

Wed 7/10

3:30 p.m.-9:04 p.m.

1 stop8h 34m

C$ 839

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 21/9

7:00 a.m.-9:40 p.m.

2 stops11h 40m

London

Tue 6/10

3:30 p.m.-9:04 p.m.

1 stop8h 34m

C$ 839
Quickest round-trip

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 23/9

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

2 stops11h 00m

London

Wed 7/10

3:30 p.m.-9:04 p.m.

1 stop8h 34m

C$ 841

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 20/9

11:59 p.m.-2:55 p.m.

2 stops11h 56m

London

Sun 4/10

5:40 a.m.-3:51 p.m.

2 stops13h 11m

C$ 848

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 21/9

5:00 a.m.-5:43 p.m.

2 stops9h 43m

London

Sat 10/10

3:30 p.m.-10:56 p.m.

2 stops10h 26m

C$ 848

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/6

Showing 1-10 of 19 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$ 650, 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.

Can Cheapflights notify me if prices for flights from Seattle to London become cheaper?

Not ready to book yet? You can track prices for flights from Seattle to London on Cheapflights with our Price Alert feature and get notified when better prices are available.

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