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Cheap flights from Seattle to London, ON from C$ 235

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 6/6. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
19 Jun — 26 Jun1
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 20 May 2026.

Tue 30/67:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Tue 7/75:55 p.m.
YXU
-
SEA
1 stop27h 50m
WestJet
Deal found 16/5C$ 380
Sun 9/87:00 a.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Sat 22/85:55 p.m.
YXU
-
SEA
1 stop27h 50m
WestJet
Deal found 15/5C$ 422
Thu 10/97:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Sun 13/95:55 p.m.
YXU
-
SEA
1 stop18h 45m
WestJet
Deal found 17/5C$ 425
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 18/5C$ 430
Wed 9/910:30 a.m.
SEA
-
YXU
1 stop15h 50m
WestJet
Wed 23/96:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 18/5C$ 476
Wed 23/910:30 a.m.
SEA
-
YXU
1 stop27h 15m
WestJet
Wed 7/106:10 a.m.
YXU
-
SEA
1 stop15h 35m
WestJet
Deal found 15/5C$ 505
Tue 8/97:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Fri 11/95:55 p.m.
YXU
-
SEA
1 stop27h 50m
WestJet
Deal found 19/5C$ 514
Mon 29/67:00 a.m.
SEA
-
YXU
2 stops27h 50m
WestJet
Mon 6/75:55 p.m.
YXU
-
SEA
1 stop18h 45m
WestJet
Deal found 15/5C$ 582
Fri 5/67:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Sat 13/65:55 p.m.
YXU
-
SEA
1 stop18h 45m
WestJet
Deal found 17/5C$ 615

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 20 May 2026.

Round-trip from

C$ 380

One-way from

C$ 235
WestJet
  • WestJet
  • 30/6-7/7
  • 2 total stops
  • 34h 35m total
  • Seattle to London
Search Deals
WestJet
  • WestJet
  • 6/6
  • 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 20 May 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

Wed 23/9

10:30 a.m.-4:45 p.m.

1 stop27h 15m

London

Wed 7/10

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

1 stop15h 35m

C$ 505

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Tue 8/9

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

1 stop6h 45m

London

Fri 11/9

5:55 p.m.-6:45 p.m.

1 stop27h 50m

C$ 514

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 29/6

7:00 a.m.-1:50 p.m.

2 stops27h 50m

London

Mon 6/7

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

1 stop18h 45m

C$ 582

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Tue 30/6

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

1 stop6h 45m

London

Tue 7/7

2:40 p.m.-9:00 p.m.

2 stops33h 20m

C$ 626

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 10/9

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

1 stop6h 45m

London

Sun 13/9

2:40 p.m.-9:40 a.m.

2 stops22h 00m

C$ 659

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Mon 29/6

8:41 p.m.-5:20 a.m.

1 stop29h 39m

London

Mon 6/7

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

1 stop18h 45m

C$ 707
Quickest round-trip

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 23/9

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

1 stop6h 45m

London

Wed 7/10

6:10 a.m.-6:33 p.m.

2 stops15h 23m

C$ 749

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 9/9

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

2 stops11h 00m

London

Wed 23/9

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

2 stops11h 27m

C$ 767

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 9/8

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

1 stop6h 45m

London

Sat 22/8

6:10 a.m.-7:02 p.m.

2 stops15h 52m

C$ 773
Cheapest one-way
Quickest one-way

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Fri 5/6

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

1 stop6h 45m

C$ 432

Flights are sorted by cheapest round-trip flights first.

Deals found on 16/5

Showing 1-10 of 13 resultsSorted by cheapest first
1
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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$ 505, WestJet can have you in London, Ontario from Seattle in 27h 15m. 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.

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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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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