Find flights
Deals
When to book
Airlines
FAQs

Cheap flights from Seattle to London from C$ 396

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 17/2. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LON
26 Jan — 2 Feb1
1 adult

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

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 21 January 2025.

Round-trip from

C$ 848

One-way from

C$ 396

Popular in

June

Cheapest in

October

Average price

C$ 970

Good round-trip deal

C$ 1,279 or less

Good one-way deal

C$ 595 or less
Icelandair
  • Icelandair
  • 18/3-25/3
  • 2 total stops
  • 49h 15m total
  • Seattle to London
Search Deals
Icelandair
  • Icelandair
  • 17/2
  • 1 total stop
  • 20h 55m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 21% potential increase in price (C$ 461 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (C$ 73 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2025
Search Deals
Price to beat on a round-trip flight from Seattle/Tacoma Intl to London (LON).
Search Deals
Price to beat on a one-way flight from Seattle/Tacoma Intl to London (LON).
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 21 January 2025.

Tue 18/33:35 p.m.SEA - LHR
1 stop20h 55mIcelandair
Tue 25/38:40 p.m.LHR - SEA
1 stop28h 20mIcelandair
Deal found 21/1C$ 848
Wed 7/53:45 p.m.SEA - LGW
1 stop12h 00mIcelandair
Thu 22/53:40 p.m.LGW - SEA
1 stop13h 00mIcelandair
Deal found 19/1C$ 862
Sun 16/37:50 p.m.SEA - LHR
Nonstop9h 25mIberia
Wed 26/31:50 p.m.LHR - SEA
1 stop16h 17mIberia
Deal found 20/1C$ 864
Wed 8/104:20 p.m.SEA - LHR
1 stop15h 40mScandinavian Airlines
Wed 22/107:05 a.m.LHR - SEA
2 stops14h 55mScandinavian Airlines
Deal found 21/1C$ 867
Sun 16/311:15 a.m.SEA - LHR
1 stop12h 35mKLM
Wed 26/36:30 a.m.LHR - SEA
1 stop13h 10mKLM
Deal found 20/1C$ 875
Wed 12/25:45 p.m.SEA - LHR
Nonstop9h 25mDelta
Wed 19/26:30 a.m.LHR - SEA
1 stop13h 16mDelta
Deal found 21/1C$ 883
Mon 3/26:50 p.m.SEA - LHR
Nonstop9h 25mFinnair
Tue 18/29:25 a.m.LHR - SEA
Nonstop9h 55mFinnair
Deal found 20/1C$ 885
Wed 12/25:45 p.m.SEA - LHR
Nonstop9h 25mVirgin Atlantic
Tue 25/21:15 p.m.LHR - SEA
Nonstop10h 00mVirgin Atlantic
Deal found 20/1C$ 901
Tue 15/410:35 a.m.SEA - LHR
1 stop18h 45mLufthansa
Tue 6/56:30 a.m.LHR - SEA
2 stops23h 43mLufthansa
Deal found 21/1C$ 910
Wed 7/56:00 a.m.SEA - LGW
1 stop20h 55mMultiple Airlines
Wed 21/510:45 a.m.LGW - SEA
1 stop17h 57mMultiple Airlines
Deal found 19/1C$ 914
Wed 5/310:35 a.m.SEA - LHR
1 stop15h 35mUnited Airlines
Wed 12/33:00 p.m.LHR - SEA
2 stops38h 53mUnited Airlines
Deal found 21/1C$ 926
Sun 2/27:00 a.m.SEA - LHR
2 stops40h 30mMultiple Airlines
Wed 12/21:00 p.m.LHR - SEA
1 stop28h 57mMultiple Airlines
Deal found 20/1C$ 942

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 21 January 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 18/3

3:35 p.m.-7:30 p.m.

1 stop20h 55m

London Heathrow

Tue 25/3

8:40 p.m.-6:00 p.m.

1 stop28h 20m

C$ 848

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Wed 7/5

3:45 p.m.-11:45 a.m.

1 stop12h 00m

London Gatwick

Thu 22/5

3:40 p.m.-8:40 p.m.

1 stop13h 00m

C$ 862

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 16/3

7:50 p.m.-12:15 p.m.

Nonstop9h 25m

London Heathrow

Wed 26/3

1:50 p.m.-11:07 p.m.

1 stop16h 17m

C$ 864

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 16/3

11:15 a.m.-6:50 a.m.

1 stop12h 35m

London Heathrow

Wed 26/3

6:30 a.m.-12:40 p.m.

1 stop13h 10m

C$ 875

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 12/2

5:45 p.m.-11:10 a.m.

Nonstop9h 25m

London Heathrow

Wed 19/2

6:30 a.m.-11:46 a.m.

1 stop13h 16m

C$ 883

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 3/2

6:50 p.m.-12:15 p.m.

Nonstop9h 25m

London Heathrow

Tue 18/2

9:25 a.m.-11:20 a.m.

Nonstop9h 55m

C$ 885

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 12/2

5:45 p.m.-11:10 a.m.

Nonstop9h 25m

London Heathrow

Tue 25/2

1:15 p.m.-3:15 p.m.

Nonstop10h 00m

C$ 901

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 15/4

10:35 a.m.-1:20 p.m.

1 stop18h 45m

London Heathrow

Tue 6/5

6:30 a.m.-10:13 p.m.

2 stops23h 43m

C$ 910

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Wed 7/5

6:00 a.m.-10:55 a.m.

1 stop20h 55m

London Gatwick

Wed 21/5

10:45 a.m.-8:42 p.m.

1 stop17h 57m

C$ 914

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 5/3

10:35 a.m.-10:10 a.m.

1 stop15h 35m

London Heathrow

Wed 12/3

3:00 p.m.-10:53 p.m.

2 stops38h 53m

C$ 926

Flights are sorted by cheapest round-trip flights first.

Deals found on 20/1

Showing 1-10 of 44 results
1
2
3
...
5

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.

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 17 January 2025.

The price you pay for your flight from Seattle to London may vary depending on when you book. For the best chance of a lower fare, look to book 46 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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

Currently, January is the cheapest month in which you can book a flight from Seattle to London (average of C$ 560). Flying from Seattle to London in July is currently the most expensive (average of C$ 874). 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 21 January 2025.

It’s optimal to fly from Seattle to London in the morning. By choosing this option you can save up to 15% on the cost of your flight, compared to a flight at noon.

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 21 January 2025.

The most flights from SEA to LON are scheduled on a Friday (22 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (6 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 40.0 - 70.0 mm per month. January is typically the wettest month, when rainfall can reach 70.0 mm. July is typically the driest time to visit London when rainfall is around 40.0 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, 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 17.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 4.0 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 21 January 2025.
To help decide which airline to fly from Seattle to London, see what other customers have to say about Delta, British Airways and WestJet. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
8,521 reviews
Check prices

Food

7.3

Entertainment

7.9

Crew

8.6

Boarding

8.2

Comfort

8.0

Overall

8.0

Reviews

1 / 10

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

Delta
8.0
Very good
8,521 reviews
Delta
8.0
Very good
8,521 reviews
Check prices

Food

7.3

Entertainment

7.9

Crew

8.6

Boarding

8.2

Comfort

8.0

Overall

8.0

Reviews

1 / 10

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

KLM
7.8
Good
1,341 reviews
Delta
8.0
Very good
8,521 reviews
Check prices

Food

7.3

Entertainment

7.9

Crew

8.6

Boarding

8.2

Comfort

8.0

Overall

8.0

Reviews

1 / 10

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

Finnair
7.6
Good
1,286 reviews
Delta
8.0
Very good
8,521 reviews
Check prices

Food

7.3

Entertainment

7.9

Crew

8.6

Boarding

8.2

Comfort

8.0

Overall

8.0

Reviews

1 / 10

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

SWISS
7.5
Good
1,600 reviews
Delta
8.0
Very good
8,521 reviews
Check prices

Food

7.3

Entertainment

7.9

Crew

8.6

Boarding

8.2

Comfort

8.0

Overall

8.0

Reviews

1 / 10

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

Virgin Atlantic
7.5
Good
665 reviews
Delta
8.0
Very good
8,521 reviews
Check prices

Food

7.3

Entertainment

7.9

Crew

8.6

Boarding

8.2

Comfort

8.0

Overall

8.0

Reviews

1 / 10

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?

    Most people fly from Seattle/Tacoma Intl (SEA) if they book a flight from Seattle to London. On average, Seattle/Tacoma Intl has 13 outbound flights to London per day from 7 airlines. Seattle/Tacoma Intl is conveniently located just 18.4 km from Seattle’s city centre.

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

    According to our current data, Icelandair (C$ 848), Iberia (C$ 864), and KLM (C$ 875) offers the cheapest pricing from Seattle to London. These flights start at 27% lower than the current average price 3 months from now.

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

    C$ 396 is the cheapest one-way deal found within the past few days, from Icelandair. You may also be able to find cheap deals on WestJet and JetBlue, with prices starting from C$ 410 and C$ 521, respectively.

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

    The top 3 most reliable airlines when flying from Seattle to London are Singapore Airlines (85%), Aeromexico (85%) and KLM (80%).

  • What are the cheapest flights from Seattle to London?

    Looking at all options, your cheapest flight can be booked for C$ 589. While the most popular route (Seattle/Tacoma Intl - London Heathrow) can be booked for C$ 861 on average our data indicates C$ 1,804 when flying from Seattle to London.

  • 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, January is the cheapest month in which you can book a flight from Seattle to London (average of C$ 560). Flying from Seattle to London in July is currently the most expensive (average of C$ 874). 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

Travelling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Brentford
Hounslow
Slough
Luton
Milton Keynes
Romford
Watford
Bedford
Bromley
Southall

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Seattle to London

See prices for flight routes from nearby airports that may be better suited for you.
Seattle to Heathrow flights
Seattle to Gatwick flights
Seattle to Manchester flights

Top 7 airlines flying from Seattle to London

Discover the top 7 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 629,999 searches. Data last updated 21 January 2025.
AirlineCheapestAverageFlexibilityOn-time
IberiaCheapestC$ 634AverageC$ 941FlexibilityNo cancel feeOn-time77%
Search Iberia flights
IcelandairCheapestC$ 635AverageC$ 871FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Air FranceCheapestC$ 740AverageC$ 1,132FlexibilityNo cancel feeOn-time77%
Search Air France flights
KLMCheapestC$ 740AverageC$ 936FlexibilityNo cancel feeOn-time75%
Search KLM flights
Virgin AtlanticCheapestC$ 844AverageC$ 1,090FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
DeltaCheapestC$ 880AverageC$ 1,110FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
British AirwaysCheapestC$ 889AverageC$ 1,237FlexibilityNo cancel feeOn-time70%
Search British Airways flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Seattle to London?

Cheapflights helps you search for flights from Seattle to London via 900+ travel sites so you don’t have to. After performing a flight search, users can also filter their flight selection by filtering for price, number of stops, airlines, and so on.

Why should you use Cheapflights to find cheap flight tickets from Seattle to London?

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Seattle to London for you. Better yet — we are completely free to use.

Can Cheapflights find flights from Seattle to London with no change fees?

Users can book flights with no change fees policies with our dedicated filters. Book flights from Seattle to London flexibly with Cheapflights today.

Can Cheapflights notify me if prices for flights from Seattle to London become cheaper?

Yes! Start tracking prices for Seattle to London flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

100% Free
Cheapflights is completely free to use, so you can start saving the moment you arrive.
Book with Flexibility
Our users can plan ahead with confidence and find flights with no change fees
Travel Smart
Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.