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$212+ Cheap flights from Seattle (SEA) to London, ON (YXU)

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 5/17. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
avr. 8 — avr. 151
mar. 4/8
mar. 4/15
1 adult, Economy
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1. Tell us where you want to go

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Cheap 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 avril 3, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$212
(Flightnetwork)
Provider with most accurate pricing for Seattle/Tacoma Intl-London flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-London flights.
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From Seattle/Tacoma Intl to London
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Find flight deals from Seattle to London

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 avril 3, 2025.

This Justfly.com deal was found by Cheapflights users on 4/3. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sam. 5/317:05 amSEA - YXU
1 stop19h 09mWestJet
sam. 6/76:00 amYXU - SEA
1 stop17h 28mWestJet
Deal found 4/3$242
This United deal was found by Cheapflights users on 4/3. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sam. 5/317:59 pmSEA - YXU
2 stops15h 59mUnited Airlines
sam. 6/79:55 amYXU - SEA
2 stops18h 04mUnited Airlines
Deal found 4/3$284

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 2,558,603 searches. Data last updated avril 3, 2025.
Use the filters below to find and compare flights from Seattle to London that are best for you.

Fly from

Seattle

Fly to

London

Route

Depart

Return

Price

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

sam. 5/31

7:05 am-5:14 am

1 stop19h 09m

London

sam. 6/7

6:00 am-8:28 pm

1 stop17h 28m

$242

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

sam. 5/31

7:59 pm-2:58 pm

2 stops15h 59m

London

sam. 6/7

9:55 am-12:59 am

2 stops18h 04m

$284

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

jeu. 7/31

7:05 am-7:09 pm

1 stop9h 04m

$558

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

mer. 7/30

12:20 am-2:57 pm

2 stops11h 37m

$927

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/3

Compare providers for flights from Seattle to London

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 Seattle to London in April.
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 Seattle-London, Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-London, Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-London, Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-London, Ontario 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 Seattle-London, Ontario 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 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.

Cheapflights Insights

Everything you need to know about your flight from Seattle to London

Rainfall in London by month

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

In terms of precipitation, rainfall in London, Ontario ranges from 2.8 - 3.9 inches per month. January is typically the wettest month, when rainfall can reach 3.9 in. March is typically the driest time to visit London, Ontario when rainfall is around 2.8 in.

Temperature in London by month

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

If weather is an important factor for your trip to London, Ontario, 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 68.0 F. Travelers looking to avoid the cold should look outside of February, when temperatures are typically at their lowest (around 21.2 F).

Reviews of airlines servicing London

Get insights into the airlines that provide service to London. 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 London. Reviews last updated avril 3, 2025.
United Airlines
7.4
Good
8,619 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Entertainment

7.0

Overall

7.4

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
United Airlines
7.4
Good
8,619 reviews
United Airlines
7.4
Good
8,619 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Entertainment

7.0

Overall

7.4

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
WestJet
7.2
Good
2,795 reviews
United Airlines
7.4
Good
8,619 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Entertainment

7.0

Overall

7.4

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
Air Canada
7.0
Good
9,035 reviews
United Airlines
7.4
Good
8,619 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Entertainment

7.0

Overall

7.4

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??

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.

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

    Cheapflights users have booked flights from Seattle to London, Ontario round-trip from $212. Other airlines that can offer you cheap pricing are WestJet, from $229, and United Airlines, from $269.

  • 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

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Top airline flying from Seattle to London

Discover the top airline that operate flights from Seattle to London. 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 2,558,603 searches. Data last updated avril 3, 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$205Average$399FlexibilityNo cancel feeOn-time67%

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