Cheap Flights from Seattle (SEAA) to London Heathrow (LHR)

Compare Seattle to London Heathrow flight deals

Find the cheapest month or even day of the year to fly to London Heathrow

Book the best London Heathrow fare with no extra fees

Flight deals from Seattle to London Heathrow Airport

Looking for a cheap last-minute deal or the best return flight from Seattle to London Heathrow Airport? If you want to travel next month, return fares start from £508. Find the lowest prices on one-way and return tickets right here.

London.£196 per passenger.Departing Tue, 17 Nov.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Tue, 17 Nov, arriving in London Heathrow.Price includes taxes and charges.From £196, select.

London.£199 per passenger.Departing Mon, 4 May.One-way flight with KLM.Outbound indirect flight with KLM, departs from Seattle / Tacoma International on Mon, 4 May, arriving in London Heathrow.Price includes taxes and charges.From £199, select.

London.£210 per passenger.Departing Sat, 25 Apr.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Sat, 25 Apr, arriving in London Heathrow.Price includes taxes and charges.From £210, select.

London.£228 per passenger.Departing Tue, 13 Oct.One-way flight with Air France.Outbound indirect flight with Air France, departs from Seattle / Tacoma International on Tue, 13 Oct, arriving in London Heathrow.Price includes taxes and charges.From £228, select.

London.£235 per passenger.Departing Wed, 26 Aug.One-way flight with Alaska Airlines.Outbound indirect flight with Alaska Airlines, departs from Seattle / Tacoma International on Wed, 26 Aug, arriving in London Heathrow.Price includes taxes and charges.From £235, select.

London.£241 per passenger.Departing Sun, 27 Sep.One-way flight with Air France.Outbound indirect flight with Air France, departs from Seattle / Tacoma International on Sun, 27 Sep, arriving in London Heathrow.Price includes taxes and charges.From £241, select.

London.£262 per passenger.Departing Mon, 1 Jun.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Mon, 1 Jun, arriving in London Heathrow.Price includes taxes and charges.From £262, select.

London.£265 per passenger.Departing Sat, 28 Mar.One-way flight with Air France.Outbound indirect flight with Air France, departs from Seattle / Tacoma International on Sat, 28 Mar, arriving in London Heathrow.Price includes taxes and charges.From £265, select.

London.£276 per passenger.Departing Mon, 7 Dec.One-way flight with WestJet.Outbound indirect flight with WestJet, departs from Seattle / Tacoma International on Mon, 7 Dec, arriving in London Heathrow.Price includes taxes and charges.From £276, select.

London.£310 per passenger.Departing Thu, 16 Jul.One-way flight with Air France.Outbound indirect flight with Air France, departs from Seattle / Tacoma International on Thu, 16 Jul, arriving in London Heathrow.Price includes taxes and charges.From £310, select.

London.£348 per passenger.Departing Tue, 9 Mar.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Tue, 9 Mar, arriving in London Heathrow.Price includes taxes and charges.From £348, select.

London.£354 per passenger.Departing Mon, 4 Jan.One-way flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Mon, 4 Jan, arriving in London Heathrow.Price includes taxes and charges.From £354, select.

London.£368 per passenger.Departing Tue, 6 Oct.One-way flight with Air France.Outbound direct flight with Air France departs from Seattle / Tacoma International on Tue, 6 Oct, arriving in London Heathrow.Price includes taxes and charges.From £368, select.

London.£372 per passenger.Departing Sun, 6 Sep.One-way flight with Air France.Outbound direct flight with Air France departs from Seattle / Tacoma International on Sun, 6 Sep, arriving in London Heathrow.Price includes taxes and charges.From £372, select.

London.£380 per passenger.Departing Sun, 26 Jul.One-way flight with Air France.Outbound direct flight with Air France departs from Seattle / Tacoma International on Sun, 26 Jul, arriving in London Heathrow.Price includes taxes and charges.From £380, select.

London.£381 per passenger.Departing Mon, 4 May.One-way flight with Virgin Atlantic.Outbound direct flight with Virgin Atlantic departs from Seattle / Tacoma International on Mon, 4 May, arriving in London Heathrow.Price includes taxes and charges.From £381, select.

Find the cheapest month to fly from Seattle to London Heathrow

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

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb

Direct flights from Seattle to London Heathrow

Seattle to London Heathrow: Alternative routes

Compare routes from Seattle to London below. You may find an airport to fly into that's cheaper, faster, or easier than London Heathrow.

Seattle to London: Flight information

The things to know before you go.

Cheapest flight found	£196
Cheapest month to fly	November
Average flight time	9 hrs, 36 mins
Most popular airline	KLM
Average flights per week	195

Finding cheap flights from Seattle to London Heathrow: Frequently asked questions

How much are return flights from Seattle to London Heathrow?

The best price we found for a return flight from Seattle to London Heathrow is £508. 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 Heathrow?

9 hours and 36 minutes is the average flight time from Seattle to London Heathrow.

Which airlines fly direct from Seattle to London Heathrow?

KLM, Alaska Airlines and Delta fly direct from Seattle to London Heathrow.

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

As of March 2026, there are 195 flights per week flying from Seattle to London Heathrow.

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

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

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

After crunching the numbers on our flight calendar, we found that it is currently cheapest to fly from Seattle to London Heathrow Airport on Monday, 20 April 2026.

Can I get a direct flight from Seattle to London Heathrow Airport?

Yes – the average flight time is 9 hours and 36 minutes.

How can I find the best flight deal to London Heathrow?

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 Heathrow 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.

Travelling from Seattle to London Heathrow Airport (LHR): What you need to know

Seattle-Tacoma International Airport (SEA) is Seattle's main airport. Explore your options for booking a flight from Seattle to London Heathrow Airport (LHR) leaving from here.
Around 9 hours 30 minutes is the typical travel time on a direct Seattle to London Heathrow Airport flight.
London Heathrow Airport is located in London. The city operates on the UTC+0 timezone and is eight hours ahead of Seattle.
Seattle-Tacoma International Airport (SEA) to London Heathrow Airport (LHR) is the most popular route. There are 25 direct flights a week to choose from. If you prefer to head out later, take the last flight with Delta Air Lines at 8:25pm. Opt for the first SEA to LHR departure with British Airways at 1:30pm if getting there sooner works for you.
Your flight from Seattle to LHR won't wait if you're late, so get to the airport with time to spare. Arrive up to one hour in advance for domestic flights and two hours ahead for international travel.
July is a peak travel month. If you're heading away then or during a major holiday like Thanksgiving, Memorial Day or Christmas, turn up even earlier. Aim for at least two hours ahead for domestic flights and as much as four hours for international journeys.

Airports in Seattle

Seattle-Tacoma International Airport (SEA)

Reach your destination without the detour from Seattle-Tacoma International Airport (SEA). Direct flights from Seattle to London Heathrow Airport (LHR) are available from here.
At SEA, you can choose from various carriers that offer direct flights from Seattle to London Heathrow Airport, including:
The airline most travellers choose when flying between SEA and LHR is British Airways.
Delta is the most punctual carrier on this route, with 77.55% of its services arriving as planned.
A stopover is the ideal opportunity to take a break from travelling and possibly even visit a new city. When searching for cheap flights from Seattle to LHR leaving from Seattle-Tacoma International Airport (SEA), uncheck the 'Direct flights only' box to find all potential stops. Some popular options include:
- Paris Charles de Gaulle Airport (CDG)
- Vancouver International Airport (YVR)
- Portland International Airport (PDX)
Located around 23 kms (14 miles) from the centre of Seattle, SEA can be reached in about 25 minutes by car (depending on traffic). The journey on public transport takes roughly 35 minutes.
Booked an early flight from Seattle to London Heathrow Airport? Avoid the mad dash to the terminal (and enjoy a few extra z's) by picking one of these stays close to Seattle-Tacoma International Airport:
80% of flights departing from Seattle-Tacoma International Airport land at their destination as planned. With its strong on-time stats, you're unlikely to be delayed when setting off from SEA.

Seattle Paine Field International Airport (PAE)

PAE is about 40 kms (25 miles) from central Seattle. It'll take 40 minutes or so to get to the airport by car from the city centre. Public transport takes approximately 1 hour 30 minutes.
Want to treat yourself to an extra night away before catching your Seattle to LHR flight? Relax in a hotel near Seattle Paine Field International Airport before your break officially begins. These stays have a room with your name on it:
Most flights that depart Seattle Paine Field International Airport make it to their destination as planned. It boasts an on-time performance rate of 80%.

About London Heathrow Airport (LHR)

If you have a late flight from Seattle to London Heathrow Airport, few things top the convenience of staying close to the terminal. Pick up your luggage at baggage claim and then be showered and relaxing soon after at one of these hotels near LHR:
To secure the lowest price, reserve your vehicle around one week ahead of your Seattle to London Heathrow Airport flight.

Getting from London Heathrow Airport (LHR) to central London

From London Heathrow Airport, central London is around 24 kms (15 miles) away. It takes about 45 minutes to get to the city centre by car.
It takes around 25 minutes if you're travelling on public transport.

How to find the cheapest flights from Seattle to London Heathrow Airport (LHR)

Currently, £196 is the lowest price we've found for a one-way ticket from Seattle to London Heathrow Airport. The cheapest price for a return flight is £508. Keep in mind fares can change due to demand at the time of booking.
Snap up cheap flights from Seattle to LHR by booking six months ahead. According to our research, that's the sweet spot for picking up a bargain.
November is when you're most likely to find a bargain on a Seattle to London Heathrow Airport ticket. If you want to travel during a different time of year, the 'Whole month' tool will show you the lowest prices for every month.
Finding a cheap plane ticket from Seattle to LHR is easy with Price Alerts. All you need to do is create one of these automatic alerts and we'll let you know as soon as there's a price drop.
Find a cheap flight from Seattle to London Heathrow Airport by using the search filters. Select your preferred times, number of stops and airlines, then sort the results by 'Cheapest' for the best deals.

The best time to fly from Seattle to London Heathrow Airport (LHR)

Think about the kind of holiday you want when planning the timing of your trip. January is the quietest month to visit London. July is when most people book flights from Seattle to London Heathrow Airport (LHR), which may be perfect if you'd rather travel when it's busy.
When booking your Seattle to LHR plane ticket, consider what kind of weather you prefer. July is the warmest month in London, with temperatures ranging from 11ºC to 26ºC.
Look for cheap tickets from Seattle to London Heathrow Airport in January if you'd rather travel during cooler conditions. Temperatures are at their lowest then, ranging between 0ºC and 9ºC.

More about London

When it comes to searching for somewhere to lay your head, you'll find the most popular stays in London right here. Explore these hotels as soon as you've booked your flight from Seattle to London Heathrow Airport:
The British Museum and Westminster Abbey are just a couple of the major attractions to put on your London must-do list. Keep the adventure rolling by checking out Big Ben.

Explore more of the United Kingdom

Manchester is just one of the many cities in the United Kingdom waiting to be explored once you've seen London. Around 257 kms (160 miles) away to the northwest, its top attractions include Manchester United Museum & Stadium Tour, The Homes of Football and Museum of Science and Industry.
If you're eager to discover another corner of the United Kingdom, consider Birmingham, roughly 153 kms (95 miles) northwest of London. Birmingham Museum & Art Gallery, Birmingham Hippodrome Theatre and Bournville Experience are among its highlights.