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$281+ Cheap flights from London, ON (YXU) to Seattle (SEA)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/15. Fares are subject to change and may not be available on all flights or dates of travel.
YXU — SEA
Mar 30 — Apr 61
Sun 3/30
Sun 4/6
1 adult, Economy
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1. Tell us where you want to go
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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 March 25, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$281
(Trip.com)

Popular in

April

Cheapest in

September

Average price

$618
Provider with most accurate pricing for London-Seattle/Tacoma Intl flight deals.
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Provider most trusted by Cheapflights users for London-Seattle/Tacoma Intl flights.
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From London to Seattle/Tacoma Intl
Search Deals
Highest demand for flights based on searches. 33% potential increase in price ($242 potential increase over avg. RT price).
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Cheapest flight prices on average. 17% potential price decrease ($70 potential savings vs. average RT price).
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Average for round-trip flights in March 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 March 25, 2025.

This Trip.com deal was found by Cheapflights users on 3/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/156:00 amYXU - SEA
1 stop15h 38mWestJet
Fri 8/227:05 amSEA - YXU
1 stop9h 04mWestJet
Deal found 3/24$281
This United Airlines deal was found by Cheapflights users on 3/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/109:55 amYXU - SEA
3 stops28h 54mUnited Airlines
Thu 4/173:24 pmSEA - YXU
2 stops14h 49mUnited Airlines
Deal found 3/24$807

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 2,558,603 searches. Data last updated March 25, 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 8/15

6:00 am-6:38 pm

1 stop15h 38m

Seattle/Tacoma Intl

Fri 8/22

7:05 am-7:09 pm

1 stop9h 04m

$281

LondonSeattle

YXU - SEA

YXUSEA

London

Thu 4/10

9:55 am-11:49 am

3 stops28h 54m

Seattle/Tacoma Intl

Thu 4/17

3:24 pm-9:13 am

2 stops14h 49m

$807

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 3/30

8:00 pm-8:38 pm

2 stops27h 38m

$462

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 3/30

3:20 pm-9:41 pm

1 stop9h 21m

$575

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/24

Compare providers for flights from London to Seattle

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from London to Seattle in March.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on London, Ontario-Seattle flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on London, Ontario-Seattle flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from London, Ontario-Seattle flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on London, Ontario-Seattle flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for London, Ontario-Seattle flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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 $238). Flying from London, Ontario to Seattle in July is currently the most expensive (average of $411). 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 March 25, 2025.

Unlike in the morning, when flights are generally more expensive, you can save up to 31% on flights from London, Ontario to Seattle by exploring options for tickets at noon.

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 0.7 - 6.6 inches per month. November is typically the wettest month, when rainfall can reach 6.6 in. July is typically the driest time to visit Seattle when rainfall is around 0.7 in.

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 66.2 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 41.0 F).

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 March 25, 2025.
United Airlines
7.4
Good
8,605 reviews

Entertainment

7.0

Crew

8.1

Comfort

7.3

Boarding

7.7

Food

6.6

Overall

7.4

Reviews

1 / 20
4.0
Okay

Patti,Feb 2025

FCO - EWR

The food was inedible! We are in the food business and aren’t sure who got this contract. But prisoners eat better. The food was so bad. I ate just a small amount and it made me nauseous. Everything is over microwaved too. And what is with the options? Vegan and vegetarian, but no keto or carnivore? I get that may be more expensive. But I’d gladly pay if it even was an option. But it’s not. There are many fresh options that could have been offered that don’t have to be heated too!
United Airlines
7.4
Good
8,605 reviews
United Airlines
7.4
Good
8,605 reviews

Entertainment

7.0

Crew

8.1

Comfort

7.3

Boarding

7.7

Food

6.6

Overall

7.4

Reviews

1 / 20
4.0
Okay

Patti,Feb 2025

FCO - EWR

The food was inedible! We are in the food business and aren’t sure who got this contract. But prisoners eat better. The food was so bad. I ate just a small amount and it made me nauseous. Everything is over microwaved too. And what is with the options? Vegan and vegetarian, but no keto or carnivore? I get that may be more expensive. But I’d gladly pay if it even was an option. But it’s not. There are many fresh options that could have been offered that don’t have to be heated too!
WestJet
7.2
Good
2,785 reviews
United Airlines
7.4
Good
8,605 reviews

Entertainment

7.0

Crew

8.1

Comfort

7.3

Boarding

7.7

Food

6.6

Overall

7.4

Reviews

1 / 20
4.0
Okay

Patti,Feb 2025

FCO - EWR

The food was inedible! We are in the food business and aren’t sure who got this contract. But prisoners eat better. The food was so bad. I ate just a small amount and it made me nauseous. Everything is over microwaved too. And what is with the options? Vegan and vegetarian, but no keto or carnivore? I get that may be more expensive. But I’d gladly pay if it even was an option. But it’s not. There are many fresh options that could have been offered that don’t have to be heated too!

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?

    Currently priced at $281, WestJet will fly you from London, Ontario to Seattle and back. In addition to WestJet, many other airlines offer competitively priced options for your trip. Check Cheapflights for deals on United Airlines for as low as $807. WestJet is 40% cheaper than the average price of flights available within the next 90 days to this destination.

  • 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 $238). Flying from London, Ontario to Seattle in July is currently the most expensive (average of $411). 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

Traveling to a place near London?

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