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Cheap flights from London to Seattle from £391

LON — SEA
3 Nov — 10 Nov1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from London to Seattle/Tacoma Intl are usually found in February or January, booked 73 days in advance, depart on a Thursday or Friday and return on a Wednesday

Cheap flight deals from London to Seattle

Enter your travel dates to find the best prices.

Cheapest flights from London to Seattle

Wed 7/1010:50 -
2 stops19h 57m
Wed 14/1007:55 -
2 stops18h 05m
Deal found 30/9£414
Thu 8/1013:05 -
1 stop15h 35m
Wed 21/1019:00 -
1 stop32h 55m
Deal found 30/9£415
Thu 8/1006:15 -
1 stop13h 00m
Thu 15/1017:30 -
Nonstop9h 50m
Deal found 30/9£416
Fri 9/1009:55 -
1 stop14h 40m
Sun 11/1023:59 -
1 stop23h 16m
Deal found 30/9£417
Tue 8/1206:30 -
1 stop13h 20m
Mon 18/116:55 -
Nonstop9h 45m
Deal found 30/9£418
Thu 8/1006:00 -
2 stops20h 32m
Wed 21/1015:00 -
1 stop14h 20m
Deal found 29/9£418
Tue 13/1015:40 -
1 stop13h 00m
Sun 18/1015:40 -
1 stop15h 00m
Deal found 30/9£419
Sun 8/1113:25 -
2 stops16h 32m
Mon 23/1110:10 -
2 stops15h 10m
Deal found 28/9£419
Wed 4/1111:55 -
1 stop13h 05m
Sat 14/1114:35 -
1 stop12h 20m
Deal found 2/10£421
Fri 9/1011:45 -
1 stop12h 50m
Tue 20/1006:00 -
1 stop17h 10m
Deal found 30/9£421
Wed 4/1111:55 -
1 stop13h 05m
Tue 17/1114:35 -
1 stop12h 20m
Deal found 2/10£421
Sun 13/1206:30 -
2 stops22h 12m
Sat 16/121:55 -
1 stop14h 15m
Deal found 30/9£421

Find flight deals from London to Seattle

Round-trip from

£414

One-way from

£391

Popular in

August

Cheapest in

February

Average price

£546

Good round-trip deal

£431 or less

Good one-way deal

£399 or less
Icelandair
  • Icelandair
  • 3/11-15/11
  • 2 total stops
  • 49h 20m total
  • London to Seattle
Search Deals
6/12-31/12
  • 6/12-31/12
  • 3 total stops
  • 38h 14m total
  • London to Seattle
Search Deals
Highest demand for flights based on searches. 6% potential increase in price (£31 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (£6 potential savings vs. average return price).
Search Deals
Average for round-trip flights in October 2026
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Price to beat on a round-trip flight from London (LON) to Seattle/Tacoma Intl.
Search Deals
Price to beat on a one-way flight from London (LON) to Seattle/Tacoma Intl.
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Cheapflights Fare Finder

 
Use the filters below to find and compare flights from London to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight
Fastest return journey

LondonSeattle

LHR London Heathrow - SEA Seattle/Tacoma Intl

LHRSEA

London Heathrow

Fri 4/12

14:55-16:50

Nonstop9h 55m

Seattle/Tacoma Intl

Wed 31/12

00:00-09:00

Nonstop0h 00m

£403

LondonSeattle

LHR London Heathrow - SEA Seattle/Tacoma Intl

LHRSEA

London Heathrow

Tue 17/11

16:20-19:17

3 stops34h 57m

Seattle/Tacoma Intl

Wed 31/12

00:00-09:00

Nonstop0h 00m

£408

LondonSeattle

LHR London Heathrow - SEA Seattle/Tacoma Intl

LHRSEA

London Heathrow

Thu 31/12

16:00-10:23

1 stop26h 23m

Seattle/Tacoma Intl

Wed 31/12

00:00-09:00

Nonstop0h 00m

£428

LondonSeattle

LHR London Heathrow - SEA Seattle/Tacoma Intl

LHRSEA

London Heathrow

Tue 3/11

14:45-17:00

Nonstop10h 15m

Seattle/Tacoma Intl

Sat 14/11

18:45-12:20

Nonstop9h 35m

£430

LondonSeattle

LHR London Heathrow - SEA Seattle/Tacoma Intl

LHRSEA

London Heathrow

Fri 9/10

17:00-19:00

Nonstop10h 00m

Seattle/Tacoma Intl

Thu 22/10

21:40-15:05

Nonstop9h 25m

£431

LondonSeattle

LHR London Heathrow - SEA Seattle/Tacoma Intl

LHRSEA

London Heathrow

Thu 22/10

08:40-22:42

1 stop22h 02m

Seattle/Tacoma Intl

Wed 31/12

00:00-09:00

Nonstop0h 00m

£432

LondonSeattle

LGW London Gatwick - SEA Seattle/Tacoma Intl

LGWSEA

London Gatwick

Sat 21/11

10:00-22:05

2 stops20h 05m

Seattle/Tacoma Intl

Wed 2/12

15:25-15:45

1 stop16h 20m

£438

LondonSeattle

LHR London Heathrow - SEA Seattle/Tacoma Intl

LHRSEA

London Heathrow

Sun 15/11

20:05-23:07

2 stops35h 02m

Seattle/Tacoma Intl

Wed 31/12

00:00-09:00

Nonstop0h 00m

£446

LondonSeattle

LHR London Heathrow - SEA Seattle/Tacoma Intl

LHRSEA

London Heathrow

Sat 28/11

09:25-11:25

Nonstop10h 00m

Seattle/Tacoma Intl

Sat 5/12

14:07-12:15

1 stop14h 08m

£448

LondonSeattle

STN London Stansted - SEA Seattle/Tacoma Intl

STNSEA

London Stansted

Fri 30/10

13:30-18:00

3 stops35h 30m

Seattle/Tacoma Intl

Wed 31/12

00:00-09:00

Nonstop0h 00m

£454

Flights are sorted by cheapest return flights first.

Deals found on 2/10

Showing 1-10 of 60 resultsSorted by cheapest first
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Best time to book a flight from London to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from London with our price prediction graph.
Estimated return price

Cheapflights Insights

Everything you need to know about your flight from London to Seattle

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

Currently, February is the cheapest month in which you can book a flight from London to Seattle (average of £488). Flying from London to Seattle in July is currently the most expensive (average of £648). 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 LON to SEA?

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from London to Seattle as you normally would.

Weekly flight availability from London to Seattle

The most flights from LON to SEA are scheduled on a Tuesday (24 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (17 on average).

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

Airfare is below average for this route at the moment.
London to Seattle flights typically cost between £447 and £609 in November.
The cheapest return price found within the last 5 days was £414 on Icelandair (3 Nov–15 Nov).

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

Reykjavik (KEF) – chosen by Cheapflights users on 72% of one-stop itineraries from London to Seattle on Cheapflights.

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

Zurich (ZRH) is the most affordable one-stop option, with an average return flight price of £459.

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

Flights via Vancouver (YVR) have the shortest average one-way travel time for one-stop routes: 12h 46m.

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

Flights via Denver (DEN) offer the fastest connection on this route, with an average stopover time of 1h 18m.

How often are flights from London to Seattle delayed?

About 12% of weekly flights between London and Seattle have experienced delays in the past year, with the average delay time being 134 minutes.

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

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

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

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

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

Over the past year, Delta have had the lowest number of delays on this route, with just 5% of flights being delayed.

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

Booking 83 days in advance of your planned departure date is, on average, the best time to get cheap flights from London to Seattle. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

Reviews of airlines servicing Seattle

Read reviews from past customers who have flown with Alaska Airlines,KLM, andVirgin Atlantic from London to Seattle. 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.
Alaska Airlines
7.9
Good
13,009 reviews
Check prices

Overall

7.9

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
Alaska Airlines
7.9
Good
13,009 reviews
Alaska Airlines
7.9
Good
13,009 reviews
Check prices

Overall

7.9

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
KLM
7.8
Good
1,576 reviews
Alaska Airlines
7.9
Good
13,009 reviews
Check prices

Overall

7.9

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
Virgin Atlantic
7.4
Good
694 reviews
Alaska Airlines
7.9
Good
13,009 reviews
Check prices

Overall

7.9

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
Icelandair
6.9
Okay
756 reviews
Alaska Airlines
7.9
Good
13,009 reviews
Check prices

Overall

7.9

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.
British Airways
6.7
Okay
8,246 reviews
Alaska Airlines
7.9
Good
13,009 reviews
Check prices

Overall

7.9

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jun 2026

LHR - SEA

It's my first time flying with Alaska Airlines. All in all it was very good. Excellent crew and the meal was really good .. best mashed potato!! Black point: not waking me up for breakfast. Having departed late from London and arriving in Seattle late at night, it would have been nice to have found a meal on the table when i woke up. Although the crew was very lovely, kind and helpful, I did find it a little regimented in their approach. Also the constant interruptions announcing what we were eating next and unnecessary announcements.

Related info for your journey

  • What airport do you fly into for flights to Seattle from London?

    Located just 11.4 mi from the city center, Seattle/Tacoma Intl is the airport most travelers will use when flying to Seattle from London. Booking flights from London to Seattle/Tacoma Intl (SEA) should be relatively easy as there are 22 daily inbound flights from London from 12 different airlines.

  • How long is the flight from London to Seattle?

    A quick flight from London to Seattle can take about 10h. Alaska Airlines provides one of the quickest options available for as low as £448. There are 4783 mi between London and Seattle. This flight may include one or multiple stops.

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

    Icelandair, at £338, was found to be the cheapest airline from London to Seattle.Alternate airlines flying return to your destination include Lufthansa and United Airlines. Icelandair is priced at 40% lower than the current average price of a flight leaving 3 months from now.

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

    £340 is the cheapest one-way deal found within the past few days, from British Airways. You may also be able to find cheap deals on Icelandair and KLM, with prices starting from £344 and £351, respectively.

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

    When deciding which route to take from London to Seattle consider London Heathrow - Seattle/Tacoma Intl, London Gatwick - Seattle/Tacoma Intl or London City - Seattle/Tacoma Intl as they are the most popular.

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

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

  • What are the cheapest flights from London to Seattle?

    On average you can expect to pay £1,844 for a flight from London to Seattle. The cheapest flight overall is £361 while the most popular route, (London Heathrow - Seattle/Tacoma Intl) is currently priced at £333.

  • Can I find deals for flights from London to Seattle that include hotel bookings?

    Yes. In addition to deals on London to Seattle flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from London to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from London to Seattle.

  • Can I find deals for business class flights from London to Seattle?

    Yes. Cheapflights offers flight deals from London to Seattle 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 London to Seattle?

    Currently, February is the cheapest month in which you can book a flight from London to Seattle (average of £488). Flying from London to Seattle in July is currently the most expensive (average of £648). 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
Federal Way
SeaTac

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Fly from London to Seattle on these airlines

Virgin Atlantic flights from London to Seattle/Tacoma Intl
British Airways flights from London to Seattle/Tacoma Intl
Finnair flights from London to Seattle/Tacoma Intl

Top 10 airlines flying from London to Seattle

AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£338Average£520FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
LufthansaCheapest£339Average£528FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
United AirlinesCheapest£375Average£496FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Aer LingusCheapest£396Average£651FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
DeltaCheapest£404Average£658FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air FranceCheapest£415Average£617FlexibilityNo cancel feeOn-time77%
Search Air France flights
Virgin AtlanticCheapest£418Average£607FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
KLMCheapest£437Average£626FlexibilityNo cancel feeOn-time75%
Search KLM flights
Alaska AirlinesCheapest£438Average£588FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
British AirwaysCheapest£447Average£644FlexibilityNo cancel feeOn-time70%
Search British Airways flights

Fly with Cheapflights

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

Cheapflights makes it easy to find London to Seattle flights by helping our users search from 900+ travel sites for deals. We also provide you with filters for cabin, price, airline, airports, number of stops, and many more to narrow down that perfect flight.

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

Millions of users choose and trust Cheapflights to book the best flight deals from London to Seattle for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.

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

Certainly. Search results for flights to Seattle from London shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

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

Yes, Cheapflights offers price alerts on London to Seattle flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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