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Cheap flights from Seattle to London, ON from C$ 327

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 16/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YXU
8 Mar — 15 Mar1
1 adult

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 3 March 2025.

Round-trip from

C$ 512

One-way from

C$ 327
17/4-24/4
  • 17/4-24/4
  • 4 total stops
  • 43h 00m total
  • Seattle to London
Search Deals
16/3
  • 16/3
  • 2 total stops
  • 20h 16m total
  • Seattle to London
Search Deals

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 3 March 2025.

Thu 17/412:30 p.m.SEA - YXU
2 stops19h 50mMultiple Airlines
Thu 24/43:25 p.m.YXU - SEA
2 stops23h 10mMultiple Airlines
Deal found 3/3C$ 512
Thu 24/47:05 p.m.SEA - YXU
2 stops11h 08mAir Canada
Thu 1/56:15 a.m.YXU - SEA
2 stops9h 43mAir Canada
Deal found 3/3C$ 613
Sat 31/57:05 a.m.SEA - YXU
1 stop9h 04mWestJet
Sat 7/68:00 p.m.YXU - SEA
2 stops19h 31mWestJet
Deal found 3/3C$ 623
Thu 17/411:59 p.m.SEA - YXU
2 stops17h 20mUnited Airlines
Thu 24/43:25 p.m.YXU - SEA
1 stop9h 16mUnited Airlines
Deal found 3/3C$ 717

Find flights from Seattle to London within your budget

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 629,999 searches. Data last updated 3 March 2025.

Fly from

Seattle

Fly to

London

Route

Depart

Return

Price

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 17/4

12:30 p.m.-11:20 a.m.

2 stops19h 50m

London

Thu 24/4

3:25 p.m.-11:35 a.m.

2 stops23h 10m

C$ 512

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 24/4

7:05 p.m.-9:13 a.m.

2 stops11h 08m

London

Thu 1/5

6:15 a.m.-12:58 p.m.

2 stops9h 43m

C$ 613

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sat 31/5

7:05 a.m.-7:09 p.m.

1 stop9h 04m

London

Sat 7/6

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

2 stops19h 31m

C$ 623

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 17/4

11:59 p.m.-8:19 p.m.

2 stops17h 20m

London

Thu 24/4

3:25 p.m.-9:41 p.m.

1 stop9h 16m

C$ 717

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 16/3

7:57 p.m.-7:13 p.m.

2 stops20h 16m

C$ 327

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Sun 16/3

6:05 a.m.-8:20 p.m.

1 stop11h 15m

C$ 791

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 31/7

7:05 a.m.-7:09 p.m.

1 stop9h 04m

C$ 934

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 31/7

3:39 p.m.-7:09 p.m.

2 stops24h 30m

C$ 949

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Wed 30/7

12:30 a.m.-5:07 p.m.

2 stops13h 37m

C$ 1,333

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/3

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.

Travel insights for flights from Seattle to London

Get recent, data-driven insights about flights from Seattle to London including ideal travel times, pricing trends, and more.

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

Currently, October is the cheapest month in which you can book a flight from Seattle to London, Ontario (average of C$ 243). Flying from Seattle to London, Ontario in April is currently the most expensive (average of C$ 484). 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.

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 70.0 - 100.0 mm per month. January is typically the wettest month, when rainfall can reach 100.0 mm. March is typically the driest time to visit London, Ontario when rainfall is around 70.0 mm.

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 20.0 C. Travellers hoping to avoid the cold should look outside of February, when temperatures are typically at their lowest (around -6.0 C).

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 3 March 2025.
Delta
8.0
Very good
8,068 reviews
Check prices

Overall

8.0

Boarding

8.2

Comfort

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

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
8,068 reviews
Delta
8.0
Very good
8,068 reviews
Check prices

Overall

8.0

Boarding

8.2

Comfort

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

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
8,679 reviews
Delta
8.0
Very good
8,068 reviews
Check prices

Overall

8.0

Boarding

8.2

Comfort

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

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
2,788 reviews
Delta
8.0
Very good
8,068 reviews
Check prices

Overall

8.0

Boarding

8.2

Comfort

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

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
8,829 reviews
Delta
8.0
Very good
8,068 reviews
Check prices

Overall

8.0

Boarding

8.2

Comfort

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

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?

    Air Canada, at C$ 613, was found to be the cheapest airline from Seattle to London, Ontario.Alternate airlines to your destination round-trip include WestJet and United Airlines.

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

    For one-way options, check prices for Air Canada. According to our data, you can fly for as low as C$ 791. Users have also found prices from C$ 934 and C$ 949 on Delta and WestJet, respectively.

  • 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.

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

    Currently, October is the cheapest month in which you can book a flight from Seattle to London, Ontario (average of C$ 243). Flying from Seattle to London, Ontario in April is currently the most expensive (average of C$ 484). 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

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Need flexible booking options for your flight to London from Seattle? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

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