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Cheap flights from London, ON to Seattle from C$ 170

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 1/5. Fares are subject to change and may not be available on all flights or dates of travel.
YXU — SEA
20 Apr — 27 Apr1
1 adult

Cheap flight deals from London to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from London (YXU) to Seattle (SEA). 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 15 April 2025.

Round-trip from

C$ 253

One-way from

C$ 170

Popular in

April

Cheapest in

May

Average price

C$ 1,527
WestJet
  • WestJet
  • 15/8-22/8
  • 2 total stops
  • 34h 07m total
  • London to Seattle
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Air Canada
  • Air Canada
  • 1/5
  • 2 total stops
  • 12h 42m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 31% potential increase in price (C$ 386 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 19% potential price decrease (C$ 142 potential savings vs. average RT price).
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Average for round-trip flights in April 2025
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Find flight deals from London to Seattle

Cheapest flights from London to Seattle
Explore the most affordable flight options available from London to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 15 April 2025.

Fri 15/88:00 p.m.YXU - SEA
1 stop27h 28mWestJet
Fri 22/87:35 p.m.SEA - YXU
1 stop6h 39mWestJet
Deal found 15/4C$ 253
Fri 15/86:15 a.m.YXU - SEA
1 stop7h 55mUnited Airlines
Fri 22/85:00 p.m.SEA - YXU
2 stops21h 07mUnited Airlines
Deal found 15/4C$ 278
Sun 18/56:00 a.m.YXU - SEA
1 stop9h 58mMultiple Airlines
Sun 25/56:25 a.m.SEA - YXU
2 stops19h 49mMultiple Airlines
Deal found 14/4C$ 368
Sun 11/59:55 a.m.YXU - SEA
2 stops12h 42mAir Canada
Thu 15/57:20 a.m.SEA - YXU
2 stops22h 59mAir Canada
Deal found 15/4C$ 381
Mon 12/56:00 a.m.YXU - SEA
2 stops27h 30mDelta
Thu 15/59:50 p.m.SEA - YXU
2 stops28h 24mDelta
Deal found 15/4C$ 718

Cheapflights Fare Finder

Customize your flight search to find flights from London to Seattle 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 15 April 2025.
Use the filters below to find and compare flights from London to Seattle that are best for you.

Fly from

London

Fly to

Seattle

Route

Depart

Return

Price

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 15/8

8:00 p.m.-8:28 p.m.

1 stop27h 28m

Seattle/Tacoma Intl

Fri 22/8

7:35 p.m.-5:14 a.m.

1 stop6h 39m

C$ 253

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 15/8

6:15 a.m.-11:10 a.m.

1 stop7h 55m

Seattle/Tacoma Intl

Fri 22/8

5:00 p.m.-5:07 p.m.

2 stops21h 07m

C$ 278

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 18/5

6:00 a.m.-12:58 p.m.

1 stop9h 58m

Seattle/Tacoma Intl

Sun 25/5

6:25 a.m.-5:14 a.m.

2 stops19h 49m

C$ 368

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 11/5

9:55 a.m.-7:37 p.m.

2 stops12h 42m

Seattle/Tacoma Intl

Thu 15/5

7:20 a.m.-9:19 a.m.

2 stops22h 59m

C$ 381

LondonSeattle

YXU - SEA

YXUSEA

London

Mon 12/5

6:00 a.m.-6:30 a.m.

2 stops27h 30m

Seattle/Tacoma Intl

Thu 15/5

9:50 p.m.-5:14 a.m.

2 stops28h 24m

C$ 718

LondonSeattle

YXU - SEA

YXUSEA

London

Thu 1/5

6:15 a.m.-10:45 a.m.

1 stop7h 30m

C$ 170

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 2/5

3:45 p.m.-2:00 p.m.

3 stops25h 15m

C$ 182

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 18/5

8:00 p.m.-12:58 p.m.

1 stop19h 58m

C$ 192

Flights are sorted by cheapest round-trip flights first.

Deals found on 14/4

Best time to book a flight from London to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from London 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 London to Seattle

What is the cheapest month to book a flight from London, Ontario to Seattle?

Currently, January is the cheapest month in which you can book a flight from London, Ontario to Seattle (average of C$ 261). Flying from London, Ontario to Seattle in December is currently the most expensive (average of C$ 353). 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.

What is the cheapest time of day to fly from YXU to SEA?

Find hourly flight availability from London to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 15 April 2025.

One of the essential ways to save on airfare from London, Ontario to Seattle is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight at noon could potentially save you up to 2% on airfare.

Rainfall in Seattle by month

Plan your trip to Seattle by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Seattle ranges from 18.0 - 168.0 mm per month. November is typically the wettest month, when rainfall can reach 168.0 mm. July is typically the driest time to visit Seattle when rainfall is around 18.0 mm.

Temperature in Seattle by month

Plan your trip to Seattle by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Seattle, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 19.0 C. Travellers hoping to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 5.0 C).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated 15 April 2025.
Delta
8.0
Very good
7,918 reviews
Check prices

Boarding

8.2

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Food

7.3

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
Delta
8.0
Very good
7,918 reviews
Delta
8.0
Very good
7,918 reviews
Check prices

Boarding

8.2

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Food

7.3

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
United Airlines
7.4
Good
8,658 reviews
Delta
8.0
Very good
7,918 reviews
Check prices

Boarding

8.2

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Food

7.3

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
WestJet
7.2
Good
2,805 reviews
Delta
8.0
Very good
7,918 reviews
Check prices

Boarding

8.2

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Food

7.3

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
Air Canada
7.0
Good
9,127 reviews
Delta
8.0
Very good
7,918 reviews
Check prices

Boarding

8.2

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Food

7.3

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Related info for your journey

Find useful and relevant information for your journey from London to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What are the cheapest airlines flying from London, Ontario to Seattle round-trip?

    According to our current data, WestJet (C$ 253), United Airlines (C$ 278), and Air Canada (C$ 381) offers the cheapest pricing from London, Ontario to Seattle. WestJet is 58% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest airlines to fly from London, Ontario to Seattle one-way?

    For one-way options, check prices for Air Canada. According to our data, you can fly for as low as C$ 170. Users have also found prices from C$ 182 and C$ 192 on United Airlines and WestJet, respectively.

  • Can I find deals for flights from London to Seattle that include hotel bookings?

    Yes. In addition to deals on London to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from London to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from London to Seattle.

  • Can I find deals for business class flights from London to Seattle?

    Yes. Cheapflights offers flight deals from London to Seattle 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 London, Ontario to Seattle?

    Currently, January is the cheapest month in which you can book a flight from London, Ontario to Seattle (average of C$ 261). Flying from London, Ontario to Seattle in December is currently the most expensive (average of C$ 353). 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
SeaTac
Tukwila
Marysville
Bothell
Leavenworth
Tacoma
Olympia
Lynnwood

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Alternative routes for London to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
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Top airline flying from London to Seattle

Discover the top airline that operate flights from London to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 629,999 searches. Data last updated 15 April 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 363AverageC$ 503FlexibilityNo cancel feeOn-time67%
Search Air Canada flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from London to Seattle?

900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Seattle from London today with Cheapflights!

Why should you use Cheapflights to find cheap flight tickets from London to Seattle?

Cheapflights helps you find that perfect flight to Seattle from London by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

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

Certainly. Search results for flights to Seattle from London shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

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

Yes, Cheapflights offers price alerts on London to Seattle flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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