Cheap Flights from Seattle to London

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Flight deals from Seattle to London

Looking for a cheap last-minute deal or the best return flight from Seattle to London? Find the lowest prices on one-way and return tickets right here.

London.R 4,140 per passenger.Departing Wed, 15 Oct.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Wed, 15 Oct, arriving in London Gatwick.Price includes taxes and charges.From R 4,140, select.

London.R 4,477 per passenger.Departing Wed, 30 Jul.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Wed, 30 Jul, arriving in London Gatwick.Price includes taxes and charges.From R 4,477, select.

London.R 4,503 per passenger.Departing Mon, 19 May.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Mon, 19 May, arriving in London Heathrow.Price includes taxes and charges.From R 4,503, select.

London.R 4,503 per passenger.Departing Sun, 3 Aug.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Sun, 3 Aug, arriving in London Gatwick.Price includes taxes and charges.From R 4,503, select.

London.R 4,571 per passenger.Departing Sun, 7 Sep.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Sun, 7 Sep, arriving in London Gatwick.Price includes taxes and charges.From R 4,571, select.

London.R 4,808 per passenger.Departing Wed, 11 Jun.One-way flight with WestJet.Outbound indirect flight with WestJet, departs from Seattle / Tacoma International on Wed, 11 Jun, arriving in London Stansted.Price includes taxes and charges.From R 4,808, select.

London.R 5,521 per passenger.Departing Sat, 26 Apr.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Sat, 26 Apr, arriving in London Stansted.Price includes taxes and charges.From R 5,521, select.

London.R 6,650 per passenger.Departing Sun, 16 Nov.One-way flight with Alaska Airlines.Outbound indirect flight with Alaska Airlines, departs from Seattle / Tacoma International on Sun, 16 Nov, arriving in London Gatwick.Price includes taxes and charges.From R 6,650, select.

Find the cheapest month to fly from Seattle to London

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Seattle to London flights are currently cheapest in October.

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Direct flights from Seattle to London

Alternative Seattle to London routes

Looking for the cheapest, fastest or easiest route from Seattle to London? You could fly into the following airports instead.

Seattle to London: Flight information

The things to know before you go.

Cheapest flight found	R 4,140
Cheapest month to fly	October
Average flight time	9 hrs, 35 mins
Most popular airline	KLM
Average flights per week	169

Finding cheap flights from Seattle to London: Frequently asked questions

How many airports are there in London?

There are 6 airports in London: London City, London Heathrow, London Gatwick, London Luton, London Stansted, and London Southend.

How much are return flights from Seattle to London?

The best price we found for a return flight from Seattle to London is R 10,742. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.

How long does it take to fly from Seattle to London?

9 hours and 35 minutes is the average flight time from Seattle to London.

Which airlines fly direct from Seattle to London?

KLM, Aer Lingus and Alaska Airlines fly direct from Seattle to London.

How many flights are there a week from Seattle to London?

As of April 2025, there are 169 flights per week flying from Seattle to London.

When is the cheapest time to fly from Seattle to London?

The cheapest month to fly from Seattle to London is usually April 2025.

Which is the cheapest airport to fly into in London?

If you're flying from Seattle, the cheapest airport near London is London Gatwick – which is 40.3 km away from the centre of London. We've found flights into this airport from R 10,742.

Which upcoming date is cheapest to fly from Seattle to London on?

After crunching the numbers on our flight calendar, we found that it is currently cheapest to fly from Seattle to London on Monday, 13 October 2025.

Can I get a direct flight from Seattle to London?

Yes – the average flight time is 9 hours and 35 minutes.

How can I get the best flight deal from Seattle to London?

We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to London but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.

When is the best time to book flights to London?

We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to London is around 40 days in advance, so don’t leave your flight to the last minute.

What’s the weather like in London?

In April, the average temperature is usually around 9°C. August is typically the warmest month in London, when it usually averages around 22°C. You can expect the least rain in March. The coldest month is January, with temperatures averaging 1°C. The rainiest month is October.

Which is the cheapest airline to fly from Seattle to London with?

The cheapest airline that flies to London is Icelandair. And the cheapest airline that flies to London Heathrow Airport is Iberia.

Flying from Seattle to London: what you need to know

There are two main airports you can take off from in Seattle. Check out your options departing from Seattle-Tacoma International Airport (SEA) or Lake Union Sea Plane Base (LKE) when reserving your flight from Seattle to London.
London has a range of airports you can jet into. Make your landing at London Heathrow Airport (LHR), London Gatwick Airport (LGW) or Stansted Airport (STN). Alternatively, arrive at London Luton Airport (LTN) or London City Airport (LCY).
9 hours 26 minutes is the average time for a direct flight from Seattle to London. Operating on the UTC+0 timezone, London is 7 hours ahead of Seattle.
With 37 flights a week between the two airports, Seattle-Tacoma International Airport (SEA) to London Heathrow Airport (LHR) is the most popular route. Hop on the first flight from Seattle to London with British Airways at 13:30. If you prefer to make the most of your day before jetting off, the last departure from SEA to LHR is with Delta Air Lines at 21:20.
For stress-free travel, arrive at the airport two hours ahead of international flights and an hour before domestic departures. This will give you plenty of time to board your flight from Seattle to London.
Travelling during a popular month such as July? Major public holidays and other popular periods can lead to longer lines and delays at security. Play it safe and arrive up to four hours before international flights and two hours before domestic departures.
If you have a passport from United States and plan to travel to United Kingdom for tourism purposes, you won't need a visa. However, entry and visa requirements may differ based on the reason for your trip and are subject to change. For the latest rules, contact your destination's nearest embassy or consulate before reserving a cheap flight from Seattle to London.

Flying from Seattle

Seattle-Tacoma International Airport (SEA)

Depart from Seattle-Tacoma International Airport (SEA) on a nonstop flight from Seattle to London. From SEA, you can fly directly into London Heathrow Airport (LHR).
At SEA, you'll find a good selection of airlines offering direct flights from Seattle to London, including:
We make it a breeze to plan a flight from Seattle to London with a stopover. To see all your options departing from Seattle-Tacoma International Airport, uncheck 'Direct flights only.' Then, pick a flight offering a stop long enough to see the sights of the city of your choice. Some popular stopovers include:
- Vancouver International Airport (YVR)
- Keflavik International Airport (KEF)
- Charles de Gaulle Airport (CDG)
Located around 23 kilometres from the centre of Seattle, SEA can be reached in approximately 18 minutes by car, depending on traffic. The same journey by public transport will take roughly 54 minutes.
Catching an early flight from Seattle to London? Avoid the hassle of rushing to the airport (and get some extra shut-eye) by choosing one of these stays close to Seattle-Tacoma International Airport:

Lake Union Sea Plane Base Airport (LKE)

Visit family or friends or just take a moment to stretch your legs with a stopover. If you'd like to split up your flight from Seattle to London, browse these options when taking off from Seattle-Tacoma International Airport:
- Vancouver International Airport (YVR)
- Keflavik International Airport (KEF)
- Charles de Gaulle Airport (CDG)
You can reach LKE from central Seattle in approximately 11 minutes by car, depending on traffic. The ride by public transport takes roughly 23 minutes to travel the 3 kilometres or so.
Start your holiday sooner with an extra night away from home. Before catching your flight from Seattle to London, take things easy in one of these hotels close to Lake Union Sea Plane Base Airport:

Arriving in London

London Heathrow Airport (LHR)

London Heathrow Airport (LHR) to central London is approximately 31 kilometres. It takes about 57 minutes to get to the centre driving.
It takes around 1 hour and 1 minute if you're travelling by public transport.
Book a hotel near LHR if you're taking a late flight from Seattle to London. Select one of these accommodation options and skip the long transfer:

London Gatwick Airport (LGW)

Once your flight from Seattle to London has touched down, you can make your way to the city centre in around 1 hour and 19 minutes by car. Central London is roughly 80 kilometres from London Gatwick Airport (LGW).
You can also travel using public transport, which will take approximately 1 hour and 26 minutes.
After your flight from Seattle to London, tuck yourself in at a hotel close to LGW. These are some great accommodation options that'll help you slip into relaxation mode:

How to find the cheapest flights from Seattle to London

Right now, R 4,140 is the best price we've seen for a one-way ticket from Seattle to London. The cheapest price for a return flight is R 10,742. Remember fares can change due to availability at the time of booking.
Book 3 months before flying. After crunching the numbers on our calendar, this is how far you should book ahead to find cheap tickets from Seattle to London.
Schedule your trip for November. That's the cheapest month for tickets from Seattle to London. If your travel dates are flexible, use the 'Whole month' tool to find the cheapest price across each month.
Create a Price Alert for cheap tickets from Seattle to London. There's no need to check back in every day to see whether prices have dropped. We'll let you know when there's a change in price.
Tailor your flights using filters. Pick your preferred arrival and departure times, airlines and total journey duration. You can also sort the results by 'Cheapest,' 'Best' or 'Fastest' flights from Seattle to London.

Best time to go to London

February is the quietest month for flights from Seattle to London, while July is the most popular. Find the best time to go to London based on whether you prefer a laid-back vibe or a lively atmosphere.
Schedule your flight from Seattle to London for July if you want to explore the city during its warmest month. Expect temperatures in London to range from 11ºC to 26ºC.
Search for cheap tickets from Seattle to London in January if you like travelling in cooler conditions. Temperatures are at their lowest around then, ranging between 0ºC and 9ºC on average.

More about London

Once you've booked your flight from Seattle to London, think about where to rest your head in this city. Make one of these accommodation options your base for exploring London:
There are so many things to do and see in this city it can be hard to know where to start. Big Ben, The British Museum and Buckingham Palace are top sights which should feature on any well-planned London itinerary.

Complete your London trip with a car rental

Discover our lineup of car rentals once you've found your hotel and cheap flight from Seattle to London. Whether you're looking for an SUV, a compact ride or even something that'll turn heads, you can compare companies in one go to find the best deal.