London

$268+ Cheap flights from Seattle (SEA) to London (LON)

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 5/4. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LON
Apr 9 — Apr 161
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Find cheap flights from Seattle to London with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

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3. Compare prices and book

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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London are usually found in January or October, booked 46 days in advance, depart on a Tuesday or Monday and return on a Wednesday

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 (LON). 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 4, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$596
(Gotogate)

One-way from

$268
(oojo)

Popular in

June

Cheapest in

January

Average price

$680

Good round-trip deal

$716 or less

Good one-way deal

$496 or less
Provider with most accurate pricing for Seattle/Tacoma Intl-London (LON) flight deals.
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-London (LON) flights.
From Seattle/Tacoma Intl to London (LON)
One-way flight from Seattle/Tacoma Intl to London (LON)
Highest demand for flights based on searches. 20% potential increase in price ($210 potential increase over avg. RT price).
Cheapest flight prices on average. 4% potential price decrease ($33 potential savings vs. average RT price).
Average for round-trip flights in April 2025
Price to beat on a round-trip flight from Seattle/Tacoma Intl to London (LON).
Price to beat on a one-way flight from Seattle/Tacoma Intl to London (LON).

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 4, 2025.

This Gotogate 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/2010:25 amSEA - LHR
2 stops17h 25mAir Canada
Tue 5/69:30 amLHR - SEA
1 stop18h 07mAir Canada
Deal found 4/3$596
This Icelandair deal was found by Cheapflights users on 4/4. 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 Icelandair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/117:00 pmSEA - LGW
1 stop11h 35mIcelandair
Mon 8/253:40 pmLGW - SEA
1 stop13h 00mIcelandair
Deal found 4/4$597
This Cheapflightsfares 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/126:50 pmSEA - LHR
Nonstop9h 25mBritish Airways
Wed 11/193:00 pmLHR - SEA
Nonstop9h 55mBritish Airways
Deal found 4/3$597
This Mytrip deal was found by Cheapflights users on 4/2. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/17:20 amSEA - LGW
2 stops19h 25mMultiple Airlines
Thu 5/87:00 pmLGW - SEA
3 stops35h 13mMultiple Airlines
Deal found 4/2$598
This Travelis deal was found by Cheapflights users on 4/4. 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 Travelis is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/205:35 pmSEA - LHR
Nonstop9h 45mVirgin Atlantic
Tue 5/61:25 pmLHR - SEA
Nonstop10h 20mVirgin Atlantic
Deal found 4/4$598
This Iberia 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/201:30 pmSEA - LHR
Nonstop9h 20mIberia
Thu 5/13:30 pmLHR - SEA
1 stop15h 39mIberia
Deal found 4/3$600
This Mytrip deal was found by Cheapflights users on 4/4. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/283:45 pmSEA - STN
2 stops16h 20mMultiple Airlines
Fri 5/27:15 amSTN - SEA
2 stops18h 35mMultiple Airlines
Deal found 4/4$601
This American Airlines 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/66:20 amSEA - LGW
2 stops18h 15mAmerican Airlines
Tue 5/1310:40 amLGW - SEA
2 stops20h 17mAmerican Airlines
Deal found 4/3$601
This Icelandair deal was found by Cheapflights users on 4/4. 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 Icelandair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/411:30 pmSEA - LHR
1 stop12h 50mIcelandair
Tue 9/99:25 pmLHR - SEA
1 stop22h 00mIcelandair
Deal found 4/4$601
This FlightHub deal was found by Cheapflights users on 4/2. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/247:20 amSEA - LHR
1 stop15h 10mMultiple Airlines
Thu 10/28:40 amLHR - SEA
2 stops17h 56mMultiple Airlines
Deal found 4/2$603
This United deal was found by Cheapflights users on 4/4. 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.
Sun 4/208:50 amSEA - LHR
1 stop16h 50mUnited Airlines
Wed 4/3010:50 amLHR - SEA
1 stop14h 09mUnited Airlines
Deal found 4/4$612
This Delta deal was found by Cheapflights users on 4/4. 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.
Wed 4/238:20 pmSEA - LHR
Nonstop9h 55mDelta
Wed 5/79:00 amLHR - SEA
1 stop16h 25mDelta
Deal found 4/4$613

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 4, 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 - LHR

SEALHR

Seattle/Tacoma Intl

Sun 4/20

10:25 am-11:50 am

2 stops17h 25m

London Heathrow

Tue 5/6

9:30 am-7:37 pm

1 stop18h 07m

$596

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Mon 8/11

7:00 pm-2:35 pm

1 stop11h 35m

London Gatwick

Mon 8/25

3:40 pm-8:40 pm

1 stop13h 00m

$597

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 4/20

3:15 pm-1:10 pm

1 stop13h 55m

London Heathrow

Tue 5/6

6:15 am-5:25 pm

1 stop19h 10m

$597

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Thu 5/1

7:20 am-10:45 am

2 stops19h 25m

London Gatwick

Thu 5/8

7:00 pm-10:13 pm

3 stops35h 13m

$598

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 4/20

1:30 pm-6:50 am

Nonstop9h 20m

London Heathrow

Tue 4/29

12:00 pm-9:14 pm

1 stop17h 14m

$600

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Tue 5/6

6:20 am-8:35 am

2 stops18h 15m

London Gatwick

Tue 5/13

10:40 am-10:57 pm

2 stops20h 17m

$601

SeattleLondon

SEA - STN

SEASTN

Seattle/Tacoma Intl

Mon 4/28

3:45 pm-4:05 pm

2 stops16h 20m

London Stansted

Fri 5/2

7:15 am-5:50 pm

2 stops18h 35m

$601

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 9/4

11:30 pm-8:20 pm

1 stop12h 50m

London Heathrow

Mon 9/8

9:25 pm-11:25 am

1 stop22h 00m

$601

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 9/24

5:45 am-10:00 am

2 stops20h 15m

London Heathrow

Wed 10/8

6:00 am-6:36 pm

2 stops20h 36m

$603

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 4/20

8:50 am-9:40 am

1 stop16h 50m

London Heathrow

Wed 4/30

10:50 am-4:59 pm

1 stop14h 09m

$612

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/3

Showing 1-10 of 60 results
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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*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*2 stars
oojoPrice Accuracy3 starsTrust Score*2 stars
MytripPrice Accuracy3 starsTrust Score*3 stars
GotogatePrice Accuracy3 starsTrust Score*3 stars
OvagoPrice Accuracy3 starsTrust Score*3 stars
CheapTicketsDealPrice 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 flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-London flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-London flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-London 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 flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

The best insider tips for Seattle to London flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to London trip
Airports
SEA

Use SEA Spot Saver to book security screening appointments in advance, reducing wait times for non-expedited passengers.

Read more about SEAby Brandon Schultz
LHR

Take the Heathrow Express for the fastest route to central London, reaching Paddington Station quickly.

Read more about LHRby Ramsey Qubein
Our travel experts
Ramsey Qubein

Ramsey Qubein

Expert on LHR

Ramsey Qubein

Ramsey Qubein

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz

Brandon Schultz

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

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

How far ahead should I book a flight from Seattle to London?

Use this chart to determine the optimal time to book a round-trip flight from Seattle to London. Price data was last updated on March 28, 2025.

Booking 46 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to London. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, November is the cheapest month in which you can book a flight from Seattle to London (average of $661). Flying from Seattle to London in June is currently the most expensive (average of $1,110). 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 SEA to LON?

Find hourly flight availability from Seattle to London. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 4, 2025.

One of the essential ways to save on airfare from Seattle to London is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight in the afternoon could potentially save you up to 9% on airfare.

What is the cheapest day to fly from Seattle to London?

Use this chart to determine the cheapest time to fly round-trip from Seattle to London. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Seattle to London flight should consider departing on Tuesday at noon when fares are most often at their lowest. Friday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Seattle to London

Explore weekly flight availability from Seattle to London. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated April 4, 2025.

The most flights from SEA to LON are scheduled on a Friday (22 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (10 on average).

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 ranges from 1.6 - 2.8 inches per month. January is typically the wettest month, when rainfall can reach 2.8 in. July is typically the driest time to visit London when rainfall is around 1.6 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, 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 62.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 39.2 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 4, 2025.
See what other customers who have flown with Delta, KLM and SWISS from Seattle to London have to say. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
8.0
Very good

Entertainment

7.9

Overall

8.0

Comfort

8.0

Crew

8.5

Boarding

8.2

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.
8.0
Very good
8.0
Very good

Entertainment

7.9

Overall

8.0

Comfort

8.0

Crew

8.5

Boarding

8.2

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.
8.0
Very good

Entertainment

7.9

Overall

8.0

Comfort

8.0

Crew

8.5

Boarding

8.2

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.
8.0
Very good

Entertainment

7.9

Overall

8.0

Comfort

8.0

Crew

8.5

Boarding

8.2

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.
8.0
Very good

Entertainment

7.9

Overall

8.0

Comfort

8.0

Crew

8.5

Boarding

8.2

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.
8.0
Very good

Entertainment

7.9

Overall

8.0

Comfort

8.0

Crew

8.5

Boarding

8.2

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 airport do you fly from for flights from Seattle to London?

    If you book a flight to London from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 17 flights from Seattle/Tacoma Intl to London per day from 15 different airlines.

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

    Cheapflights users have booked flights from Seattle to London round-trip from $596. Other airlines that can offer you cheap pricing are Icelandair, from $597, and Virgin Atlantic, from $597. Users have found that Air Canada is 26% cheaper than the other options available to this destination.

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

    One-way options have recently been found by users for as low as $268 on Icelandair. Other airlines that offer cheap prices include JetBlue from $369 and Iberia from $376 one-way.

  • What are the most popular routes from Seattle to London?

  • What are the most reliable airlines from Seattle to London?

    Consider KLM (83%), Singapore Airlines (81%) or Aeromexico (81%) when booking your flight. These represent the most reliable airlines when flying from Seattle to London.

  • What are the cheapest flights from Seattle to London?

    Looking at all options, your cheapest flight can be booked for $412. While the most popular route (Seattle/Tacoma Intl - London Heathrow) can be booked for $550 on average our data indicates $2,798 when flying from Seattle to London.

  • Where are the most common layover locations when flying from Seattle to London?

  • What are some popular things to do or see while on a layover in Reykjavik?

    Reykjavik travelers tend to visit Hallgrímskirkja, Harpa, and Laugardalslaug Geothermal Pool more than anywhere else. Hallgrímskirkja, Harpa, and Laugardalslaug Geothermal Pool are located about 23.2 mi, 23.3 mi, and 24.6 mi, respectively from Reykjavik Keflavik Intl. Travelers in need of a car in Reykjavik can rent one for about $52 per day.

  • Where are the least popular layover locations for Seattle to London flights?

  • 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?

    Currently, November is the cheapest month in which you can book a flight from Seattle to London (average of $661). Flying from Seattle to London in June is currently the most expensive (average of $1,110). 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 Seattle?

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Top 10 airlines flying from Seattle to London

Discover the top 10 airlines 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 4, 2025.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest$378Average$768FlexibilityNo cancel feeOn-time76%
United AirlinesCheapest$498Average$891FlexibilityNo cancel feeOn-time69%
IcelandairCheapest$508Average$680FlexibilityNo cancel feeOn-time76%
IberiaCheapest$582Average$731FlexibilityNo cancel feeOn-time77%
Aer LingusCheapest$583Average$793FlexibilityNo cancel feeOn-timeN/A
FinnairCheapest$597Average$785FlexibilityNo cancel feeOn-time76%
KLMCheapest$597Average$839FlexibilityNo cancel feeOn-time75%
Air FranceCheapest$615Average$931FlexibilityNo cancel feeOn-time77%
DeltaCheapest$615Average$872FlexibilityNo cancel feeOn-timeN/A
British AirwaysCheapest$621Average$879FlexibilityNo cancel feeOn-time70%

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