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$84+ Cheap flights from Seattle (SEA) to London, ON (YXU)

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 5/10. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
Apr 29 — May 61
Tue 4/29
Tue 5/6
1 adult, Economy
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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 April 24, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$194
(Justfly.com)

One-way from

$84
(Air Canada)
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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One-way flight 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 April 24, 2025.

This Justfly.com deal was found by Cheapflights users on 4/22. 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.
Tue 7/297:35 pmSEA - YXU
1 stop6h 39mWestJet
Sun 8/246:00 amYXU - SEA
1 stop9h 58mWestJet
Deal found 4/22$194
This Flightnetwork deal was found by Cheapflights users on 4/22. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/61:15 pmSEA - YXU
2 stops12h 59mMultiple Airlines
Fri 6/136:15 amYXU - SEA
1 stop7h 36mMultiple Airlines
Deal found 4/22$197
This Flightnetwork deal was found by Cheapflights users on 4/23. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/710:00 amSEA - YXU
2 stops20h 18mAir Canada
Sat 6/146:15 amYXU - SEA
1 stop7h 36mAir Canada
Deal found 4/23$213
This United Airlines deal was found by Cheapflights users on 4/22. 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.
Sun 7/2711:45 pmSEA - YXU
2 stops12h 12mUnited Airlines
Sun 8/246:15 amYXU - SEA
1 stop7h 55mUnited Airlines
Deal found 4/22$232
This Delta deal was found by Cheapflights users on 4/22. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/257:35 pmSEA - YXU
1 stop6h 39mDelta
Wed 7/306:00 amYXU - SEA
1 stop9h 58mDelta
Deal found 4/22$316

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 April 24, 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

Tue 7/29

7:35 pm-5:14 am

1 stop6h 39m

London

Sun 8/24

6:00 am-12:58 pm

1 stop9h 58m

$194

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Fri 6/6

1:15 pm-5:14 am

2 stops12h 59m

London

Fri 6/13

6:15 am-10:51 am

1 stop7h 36m

$197

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sat 6/7

10:00 am-9:18 am

2 stops20h 18m

London

Sat 6/14

6:15 am-10:51 am

1 stop7h 36m

$213

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 7/27

11:45 pm-2:57 pm

2 stops12h 12m

London

Sun 8/24

6:15 am-11:10 am

1 stop7h 55m

$232

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Fri 7/25

7:35 pm-5:14 am

1 stop6h 39m

London

Wed 7/30

6:00 am-12:58 pm

1 stop9h 58m

$316

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sat 5/10

11:30 am-9:29 pm

1 stop6h 59m

$84

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sat 5/10

11:35 pm-3:04 pm

2 stops12h 29m

$99

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sat 6/7

7:05 am-7:09 pm

1 stop9h 04m

$223

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/22

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*2 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 eDreams the most. eDreams 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 April 24, 2025.
Get a feel of what it's like to fly with Delta, United Airlines and WestJet from Seattle to London by reading reviews from past customers. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,920 reviews

Comfort

7.9

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Delta
8.0
Very good
7,920 reviews
Delta
8.0
Very good
7,920 reviews

Comfort

7.9

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
United Airlines
7.4
Good
8,685 reviews
Delta
8.0
Very good
7,920 reviews

Comfort

7.9

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
WestJet
7.2
Good
2,816 reviews
Delta
8.0
Very good
7,920 reviews

Comfort

7.9

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Air Canada
7.0
Good
9,195 reviews
Delta
8.0
Very good
7,920 reviews

Comfort

7.9

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

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 $194. Other airlines that can offer you cheap pricing are Air Canada, from $213, and United Airlines, from $232.

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

    The cheapest airline one-way is Air Canada, with whom users have recently found tickets for as low as $84. However, be on the lookout for offers from United Airlines and WestJet, as they are both options that can get you from Seattle to London, Ontario for a low price.

  • 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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Alternative routes for Seattle to London

See prices for flight routes from nearby airports that may be better suited for you.
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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 April 24, 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$205Average$399FlexibilityNo cancel feeOn-time67%

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