Find flights
Deals
When to book
Airlines
FAQs

Cheap flights from Seattle to London from £352

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 13/8. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LON
5 Jun — 12 Jun1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London are usually found in January or October, booked 51 days in advance, depart on a Tuesday or Thursday and return on a Wednesday

Cheap flight deals from Seattle to London

Enter your travel dates to find the best prices.

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 6 May 2026.

Tue 11/823:25
SEA
-
STN
2 stops16h 45m
Multiple Airlines
Tue 25/819:15
STN
-
SEA
2 stops24h 30m
Multiple Airlines
Deal found 3/5£588
Wed 30/919:00
SEA
-
LGW
1 stop11h 40m
Icelandair
Mon 5/1015:40
LGW
-
SEA
1 stop34h 15m
Icelandair
Deal found 4/5£588
Tue 8/915:55
SEA
-
LHR
2 stops33h 40m
Scandinavian Airlines
Sat 19/906:40
LHR
-
SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 1/5£588
Sun 7/608:00
SEA
-
STN
2 stops31h 20m
Multiple Airlines
Tue 23/607:10
STN
-
SEA
3 stops34h 57m
Multiple Airlines
Deal found 1/5£588
Sat 26/915:55
SEA
-
LHR
2 stops21h 40m
Scandinavian Airlines
Mon 5/1017:30
LHR
-
SEA
2 stops28h 15m
Scandinavian Airlines
Deal found 1/5£589
Sun 31/515:55
SEA
-
STN
2 stops20h 00m
Multiple Airlines
Sun 7/605:55
STN
-
SEA
2 stops15h 50m
Multiple Airlines
Deal found 3/5£590
Thu 4/619:00
SEA
-
LGW
2 stops17h 00m
Multiple Airlines
Tue 9/617:50
LGW
-
SEA
2 stops25h 55m
Multiple Airlines
Deal found 3/5£590
Sat 12/915:55
SEA
-
LHR
2 stops16h 30m
Scandinavian Airlines
Sat 26/906:40
LHR
-
SEA
2 stops15h 05m
Scandinavian Airlines
Deal found 3/5£590
Thu 1/1015:40
SEA
-
LGW
1 stop15h 00m
Icelandair
Sat 10/1015:40
LGW
-
SEA
1 stop13h 00m
Icelandair
Deal found 30/4£591
Sat 12/915:55
SEA
-
LHR
2 stops16h 30m
Scandinavian Airlines
Fri 18/907:05
LHR
-
SEA
2 stops14h 40m
Scandinavian Airlines
Deal found 3/5£591
Sat 24/1018:35
SEA
-
LGW
1 stop17h 15m
Condor
Sat 31/1009:55
LGW
-
SEA
1 stop13h 40m
Condor
Deal found 2/5£591
Tue 11/815:40
SEA
-
LGW
2 stops19h 35m
Multiple Airlines
Thu 20/811:00
LGW
-
SEA
2 stops32h 45m
Multiple Airlines
Deal found 2/5£592

Find 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 6 May 2026.

Round-trip from

£588

One-way from

£352

Popular in

June

Cheapest in

January

Average price

£643

Good round-trip deal

£683 or less

Good one-way deal

£405 or less
11/8-25/8
  • 11/8-25/8
  • 4 total stops
  • 41h 15m total
  • Seattle to London
Search Deals
13/8
  • 13/8
  • 1 total stop
  • 13h 35m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 18% potential increase in price (£94 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£15 potential savings vs. average return price).
Search Deals
Average for round-trip flights in May 2026
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

Cheapflights Fare Finder

 
Customise 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 858,174 searches. Data last updated 6 May 2026.
Use the filters below to find and compare flights from Seattle to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 11/8

23:25-20:20

1 stop12h 55m

London Heathrow

Wed 26/8

13:05-20:40

1 stop15h 35m

£632

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 2/9

21:50-15:35

Nonstop9h 45m

London Heathrow

Wed 9/9

06:30-11:47

1 stop13h 17m

£666

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 16/8

21:45-15:35

Nonstop9h 50m

London Heathrow

Tue 25/8

06:30-11:37

1 stop13h 07m

£667

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 24/8

14:26-12:25

1 stop13h 59m

London Heathrow

Fri 28/8

10:50-16:59

1 stop14h 09m

£670

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Thu 1/10

12:02-14:45

2 stops18h 43m

London Gatwick

Sat 24/10

10:20-16:00

1 stop13h 40m

£687

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Wed 27/5

17:40-14:45

1 stop13h 05m

London Gatwick

Wed 10/6

19:40-16:00

1 stop28h 20m

£702

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Tue 16/6

18:05-18:50

1 stop16h 45m

London Gatwick

Sun 21/6

19:35-16:10

1 stop28h 35m

£703

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 24/9

21:50-15:35

Nonstop9h 45m

London Heathrow

Thu 15/10

11:45-16:39

1 stop12h 54m

£703

SeattleLondon

SEA - LCY

SEALCY

Seattle/Tacoma Intl

Tue 18/8

13:50-09:30

1 stop11h 40m

London City

Thu 27/8

09:20-16:27

1 stop15h 07m

£707

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 25/8

21:45-15:35

Nonstop9h 50m

London Heathrow

Sat 12/9

06:15-11:15

1 stop13h 00m

£709

Flights are sorted by cheapest return flights first.

Deals found on 5/5

Showing 1-10 of 60 resultsSorted by cheapest first
1
2
3
...
6

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 return 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?

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 64 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 £236). Flying from Seattle to London in May is currently the most expensive (average of £1,376). 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 6 May 2026.

When flying from Seattle to London, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

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 6 May 2026.

The most flights from SEA to LON are scheduled on a Tuesday (22 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (18 on average).

How much does it cost for a return flight from Seattle to London?

What’s the top stopover airport for flights from Seattle to London?

Share of one-stop return flights from Seattle to London chosen by Cheapflights users in the past 12 months, using the same stopover each way.

Reykjavik (KEF) – chosen by Cheapflights users on 47% of one-stop itineraries from Seattle to London on Cheapflights.

What’s the cheapest stopover airport for flights from Seattle to London?

Average return fare for one-stop flights from Seattle to London, chosen by Cheapflights users in the past 12 months, with the same stopover each way.

Reykjavik (KEF) is the most affordable one-stop option, with an average return flight price of £369.

What’s the fastest stopover option from Seattle to London?

Shortest average travel time for one-stop one-way flights from Seattle to London, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by stopover airport.

Flights via Dublin (DUB) have the shortest average one-way travel time for one-stop routes: 11h 55m.

Which airport typically offers the quickest stopover for flights from Seattle to London?

Average stopover duration for one-stop one-way flights from Seattle to London, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Reykjavik (KEF) offer the fastest connection on this route, with an average stopover time of 1h 25m.

How often are flights from Seattle to London delayed?

About 15% of weekly flights between Seattle and London have experienced delays in the past year, with the average delay time being 128 minutes.

What is the most punctual flight time for Seattle to London flights?

Historically, flights departing in the early afternoon are less likely to be delayed, whereas flights leaving in the evening tend to experience delays more often.

What day of the week experiences the fewest flight delays on this route?

Tuesday tends to have the lowest number of delays on this route, whereas Wednesday has historically faced a higher average of delays compared to other days of the week.

Which airline has the best punctuality record on Seattle to London flights?

Over the past year, Virgin Atlantic have had the lowest number of delays on this route, with just 7% of flights being delayed.

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 6 May 2026.
Get a feel of what it's like to fly with KLM,Virgin Atlantic, andIcelandair from Seattle to London by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
KLM
7.8
Good
1,511 reviews
Check prices

Entertainment

7.2

Food

7.3

Boarding

7.8

Crew

8.4

Overall

7.8

Comfort

7.7

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
KLM
7.8
Good
1,511 reviews
KLM
7.8
Good
1,511 reviews
Check prices

Entertainment

7.2

Food

7.3

Boarding

7.8

Crew

8.4

Overall

7.8

Comfort

7.7

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
Virgin Atlantic
7.4
Good
688 reviews
KLM
7.8
Good
1,511 reviews
Check prices

Entertainment

7.2

Food

7.3

Boarding

7.8

Crew

8.4

Overall

7.8

Comfort

7.7

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
Icelandair
7.0
Good
650 reviews
KLM
7.8
Good
1,511 reviews
Check prices

Entertainment

7.2

Food

7.3

Boarding

7.8

Crew

8.4

Overall

7.8

Comfort

7.7

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
British Airways
6.7
Okay
7,944 reviews
KLM
7.8
Good
1,511 reviews
Check prices

Entertainment

7.2

Food

7.3

Boarding

7.8

Crew

8.4

Overall

7.8

Comfort

7.7

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful

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?

    Seattle/Tacoma Intl (SEA) is the airport you will fly out of if you book a flight from Seattle to London. You should not have trouble finding flights to London from Seattle/Tacoma Intl; the airport handles an average of 21 outbound flights to London per day. You should also have plenty of airline options to choose from since 2 airlines have flights from the Seattle airport to London. It is only a 11.4 mi journey to Seattle/Tacoma Intl (SEA) from Seattle’s city center.

  • How long is the flight from Seattle to London?

    Airlines like Icelandair, KLM, and Delta fly from Seattle to London in about 9h 45m. The time it takes to get you to your destination can typically vary by up to 3h 10m. The distance from Seattle to London is about 4783 mi. Both multi-stop and direct flights can be found to your destination and back.

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

    Cheapflights users have booked flights from Seattle to London round-trip from £350. Another airline that can offer you cheap pricing is Virgin Atlantic. British Airways is currently priced 38% below the average price you’ll pay for this route.

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

    The cheapest airline one-way is Icelandair, with whom users have recently found tickets for as low as £159. However, be on the lookout for offers from Virgin Atlantic and British Airways, as they are both options that can get you from Seattle to London for a low price.

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

    The most popular route from Seattle to London is Seattle/Tacoma Intl - London Heathrow. You may also consider Seattle/Tacoma Intl - London Gatwick or Seattle/Tacoma Intl - London Stansted.

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

    No one likes to see their flight delayed. When booking a flight from Seattle to London consider choosing KLM (95%), Delta (95%) or Virgin Atlantic (95%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Seattle to London?

    The cheapest flight price from Seattle to London is £237. On average you can expect to pay £940. The most popular route, (Seattle/Tacoma Intl - London Heathrow), can usually be booked for £522.

  • 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 holiday 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 £236). Flying from Seattle to London in May is currently the most expensive (average of £1,376). 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 London?

Book flights to London if you plan to visit one of these locations
Milton Keynes
Wembley
Croydon
Hounslow
Luton
Gatwick
Ilford
Slough
Hayes
Brentford
Colchester
Romford
Watford
Kingston upon Thames
Eastbourne
Ipswich
Southend-on-Sea
Guildford
Bishop's Stortford
Chelmsford

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.

Top 2 airlines flying from Seattle to London

Discover the top 2 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 858,174 searches. Data last updated 6 May 2026.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest£350Average£515FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£365Average£578FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers 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?

Deals for Seattle to London flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

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

Cheapflights simply makes it quick and affordable to book flights from Seattle to London by bringing together all flight options from hundreds of airlines and agencies online — and put it in one place for you to choose from. Plus, Cheapflights is 100% free to use for all.

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, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

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.