Cheap Flights from Seattle / Tacoma International to London

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Compare Seattle / Tacoma International to London flight deals

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Flight deals from Seattle / Tacoma International to London

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

Find the cheapest month to fly from Seattle / Tacoma International to London

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

Direct flights from Seattle / Tacoma International to London

Alternative Seattle / Tacoma International to London routes

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

Seattle to London: Flight information

The things to know before you go.
Cheapest flight foundR 4,698
Cheapest month to flyOctober
Average flight time9 hrs, 32 mins
Most popular airlineKLM
Average flights per week144

Finding cheap flights from Seattle / Tacoma International to London: Frequently asked questions

There are 6 airports in London: London City, London Heathrow, London Gatwick, London Luton, London Stansted, and London Southend.
The best price we found for a return flight from Seattle / Tacoma International to London is R 9,339. 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.
9 hours and 32 minutes is the average flight time from Seattle / Tacoma International to London.
KLM, Virgin Atlantic and Delta fly direct from Seattle / Tacoma International to London.
As of April 2025, there are 144 flights per week flying from Seattle / Tacoma International to London.
The cheapest month to fly from Seattle / Tacoma International to London is usually April 2025.
If you're flying from Seattle / Tacoma International Airport, the cheapest airport near London is London Heathrow – which is 22.9 km away from the centre of London. We've found flights into this airport from R 9,339.
After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from Seattle / Tacoma International Airport to London on Monday, 25 August 2025.
Yes – the average flight time is 9 hours and 32 minutes.
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.
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.
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.
Currently, Scandinavian Airlines and Delta offer the cheapest flight tickets to London.

Flying from Seattle-Tacoma International Airport (SEA) to London: what you need to know

  • Around 10 hours 3 minutes is how long you can expect to be travelling on a direct flight from Seattle-Tacoma International Airport to London.

  • London is 7 hours ahead of Seattle, where Seattle-Tacoma International Airport is located. London operates on the UTC+0 timezone.

  • The busiest route is from Seattle-Tacoma International Airport (SEA) to London Heathrow Airport (LHR). You can choose from 37 weekly services between these two airports. If you want to get on your way as soon as you can, the earliest flight from SEA to LHR is the 13:30 British Airways option. If you'd rather fly out later on, the last departure is at 21:20 with Delta.

  • For stress-free travel, arrive at the airport two hours ahead of international flights and one hour before domestic departures. This way, you can comfortably catch your flight from SEA to London.

  • If you're going away during a popular month like July, get to the airport even earlier. It's smart to arrive up to four hours before an international flight and two hours ahead of a domestic departure. Check-in and security lines will be longer during holiday periods like spring break and summer.

  • You can catch a direct flight from Seattle-Tacoma International Airport to London that touches down at London Heathrow Airport (LHR).

  • There's a variety of airlines offering direct flights from Seattle-Tacoma International Airport to London, such as:

  • A stopover is the perfect opportunity to take a travel break — and maybe even explore a different city. When browsing flights from SEA to London, deselect the 'Direct flights only' box to see where you can visit along the way. Popular options include:

    • Vancouver International Airport (YVR)

    • Keflavik International Airport (KEF)

    • Charles de Gaulle Airport (CDG)

  • You won't need a visa for United Kingdom if you have a passport from United States and are visiting for tourism purposes. Visa and travel documentation requirements are subject to changes. So before reserving your cheap tickets from Seattle-Tacoma International Airport to London, check with your airline and your destination country's local embassy or consulate for the latest information.

  • SEA is around 23 kilometres from central Seattle. If you're driving, catching a cab or ride-sharing from the centre, it'll take you 18 minutes or so to get there, depending on traffic conditions. If you're taking public transport, expect the journey time to be around 54 minutes.

  • Want a hassle-free start to your break? Stay near SEA. Whether you're catching an early flight from Seattle-Tacoma International Airport to London or want to avoid feeling rushed, these hotels are perfect:

How to find the cheapest flights from Seattle-Tacoma International Airport (SEA) to London

  • The lowest price we've seen for a one-way ticket from Seattle-Tacoma International Airport to London is R 4,698. The cheapest price for a return flight is R 9,339. Remember fares may change due to availability at the time of booking.

  • To pick up cheap tickets from SEA to London, reserve your trip 3 months ahead of your planned departure.

  • Schedule your trip for November. That's the cheapest month for tickets from Seattle-Tacoma International Airport to London. If you have flexibility with your dates, use the 'Whole month' tool to find the lowest price across each month.

  • Snapping up a cheap ticket from SEA to London is a breeze with Price Alerts. All you need to do is create one of these automatic alerts and we'll notify you when the price has fallen.

  • Tailor your flights with filters. Choose your preferred departure and arrival times, total journey duration and airlines. You can also sort results by 'Fastest,' 'Cheapest' or 'Best' flights from Seattle-Tacoma International Airport to London.

Airports in London

London Heathrow Airport (LHR)

  • London Heathrow Airport (LHR) to central London is approximately 31 kilometres. It'll take you about 57 minutes to get to the centre driving.

  • When travelling by public transport, expect a journey of roughly 1 hour and 1 minute.

  • Reserve a hotel near LHR if you have a late flight from Seattle-Tacoma International Airport to London. Pick one of these accommodation options and skip the long transfer:

London Gatwick Airport (LGW)

  • The centre of London is approximately 80 kilometres from London Gatwick Airport (LGW). After your flight from Seattle-Tacoma International Airport to London has touched down and you've made your way through the terminal, expect a drive of about 1 hour and 19 minutes.

  • Public transport will get you there in about 1 hour and 26 minutes.

  • Hang the 'Do not disturb' sign on your door and relax at a hotel near LGW. Here are a few options where you can kick back after your flight from SEA to London:

Best time to go to London

  • It's time to work out your trip dates for your flight from Seattle-Tacoma International Airport to London. July is the most popular month to travel to London. If you prefer a more relaxed atmosphere, go in February.

  • Book your flight from Seattle-Tacoma International Airport to London for July to experience the city during its warmest month. You can expect temperatures to range from 11ºC to 26ºC.

  • Look for cheap flights from SEA to London in January if you like cooler conditions. Temperatures are at their lowest then, ranging between 0ºC and 9ºC on average.

More about London

  • Start your London trip off on the right foot by choosing the perfect place to stay. Once you've booked your flight from Seattle-Tacoma International Airport to London, browse our range of accommodation options including:

  • All great adventures should include a little sightseeing. Big Ben, The British Museum and Buckingham Palace are must-visits when exploring London.

Complete your London trip with a car rental

  • Select one of our car rentals in London and explore the city at your leisure. Easily compare options in one go to find your ideal ride once you've booked your hotel and cheap flights from Seattle-Tacoma International Airport to London.

Prices shown on this page are estimated lowest prices only. Found in the last 45 days.