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Cheap flights from London, ON to Seattle from C$ 215

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 13/6. Fares are subject to change and may not be available on all flights or dates of travel.
YXU — SEA
4 May — 11 May1
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 29 April 2025.

Round-trip from

C$ 575

One-way from

C$ 215

Popular in

April

Cheapest in

May

Average price

C$ 1,522
WestJet
  • WestJet
  • 27/6-6/7
  • 3 total stops
  • 40h 43m total
  • London to Seattle
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United Airlines
  • United Airlines
  • 13/6
  • 1 total stop
  • 7h 36m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 32% potential increase in price (C$ 400 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 20% 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 29 April 2025.

Fri 27/66:00 a.m.YXU - SEA
2 stops21h 34mMultiple Airlines
Sun 6/77:05 a.m.SEA - YXU
1 stop19h 09mMultiple Airlines
Deal found 28/4C$ 575
Fri 27/68:00 p.m.YXU - SEA
1 stop19h 58mWestJet
Sun 6/77:05 a.m.SEA - YXU
1 stop19h 09mWestJet
Deal found 28/4C$ 723
Thu 12/66:15 a.m.YXU - SEA
1 stop7h 36mUnited Airlines
Thu 19/611:50 p.m.SEA - YXU
2 stops18h 37mUnited Airlines
Deal found 28/4C$ 740
Thu 12/66:15 a.m.YXU - SEA
1 stop7h 36mAir Canada
Thu 19/611:35 a.m.SEA - YXU
1 stop6h 52mAir Canada
Deal found 28/4C$ 746

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 29 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 27/6

6:00 a.m.-12:34 a.m.

2 stops21h 34m

Seattle/Tacoma Intl

Sun 6/7

7:05 a.m.-5:14 a.m.

1 stop19h 09m

C$ 575

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 27/6

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

1 stop19h 58m

Seattle/Tacoma Intl

Sun 6/7

7:05 a.m.-5:14 a.m.

1 stop19h 09m

C$ 723

LondonSeattle

YXU - SEA

YXUSEA

London

Thu 12/6

6:15 a.m.-10:51 a.m.

1 stop7h 36m

Seattle/Tacoma Intl

Thu 19/6

11:50 p.m.-9:27 p.m.

2 stops18h 37m

C$ 740

LondonSeattle

YXU - SEA

YXUSEA

London

Thu 12/6

6:15 a.m.-10:51 a.m.

1 stop7h 36m

Seattle/Tacoma Intl

Thu 19/6

11:35 a.m.-9:27 p.m.

1 stop6h 52m

C$ 746

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 13/6

6:15 a.m.-10:51 a.m.

1 stop7h 36m

C$ 215

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 13/6

8:00 p.m.-12:31 p.m.

2 stops43h 31m

C$ 346

Flights are sorted by cheapest round-trip flights first.

Deals found on 28/4

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 29 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 29 April 2025.
United Airlines
7.4
Good
8,696 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Crew

8.1

Overall

7.4

Boarding

7.7

Food

6.6

Reviews

1 / 20
4.0
Okay

Thomas,Apr 2025

TPE - SFO

The boarding experience was okay. The dietary food choices were limited, the midway snacks were hard and dry. The seat was uncomfortable - stiff seat cushion, seat back kept springing back to the upright position, narrow seat width. Love the app and the ability to track my luggage. Flight crew was efficient.
United Airlines
7.4
Good
8,696 reviews
United Airlines
7.4
Good
8,696 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Crew

8.1

Overall

7.4

Boarding

7.7

Food

6.6

Reviews

1 / 20
4.0
Okay

Thomas,Apr 2025

TPE - SFO

The boarding experience was okay. The dietary food choices were limited, the midway snacks were hard and dry. The seat was uncomfortable - stiff seat cushion, seat back kept springing back to the upright position, narrow seat width. Love the app and the ability to track my luggage. Flight crew was efficient.
WestJet
7.2
Good
2,823 reviews
United Airlines
7.4
Good
8,696 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Crew

8.1

Overall

7.4

Boarding

7.7

Food

6.6

Reviews

1 / 20
4.0
Okay

Thomas,Apr 2025

TPE - SFO

The boarding experience was okay. The dietary food choices were limited, the midway snacks were hard and dry. The seat was uncomfortable - stiff seat cushion, seat back kept springing back to the upright position, narrow seat width. Love the app and the ability to track my luggage. Flight crew was efficient.
Air Canada
7.0
Good
9,228 reviews
United Airlines
7.4
Good
8,696 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Crew

8.1

Overall

7.4

Boarding

7.7

Food

6.6

Reviews

1 / 20
4.0
Okay

Thomas,Apr 2025

TPE - SFO

The boarding experience was okay. The dietary food choices were limited, the midway snacks were hard and dry. The seat was uncomfortable - stiff seat cushion, seat back kept springing back to the upright position, narrow seat width. Love the app and the ability to track my luggage. Flight crew was efficient.

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$ 723), United Airlines (C$ 740), and Air Canada (C$ 746) offers the cheapest pricing from London, Ontario to Seattle.

  • 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
Tukwila
SeaTac
Tacoma
Marysville
Bothell
Olympia
Lynnwood
Leavenworth

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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 3 airlines flying from London to Seattle

Discover the top 3 airlines 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 29 April 2025.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 241AverageC$ 360FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 279AverageC$ 296FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Air CanadaCheapestC$ 362AverageC$ 455FlexibilityNo 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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