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

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

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Flight deals from Seattle to London Heathrow

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

London.£388 per passenger.Departing Mon, 9 Mar, returning Wed, 18 Mar.Return flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Mon, 9 Mar, arriving in London Heathrow.Inbound indirect flight with Icelandair, departs from London Heathrow on Wed, 18 Mar, arriving in Seattle / Tacoma International.Price includes taxes and charges.From £388, select.

London.£395 per passenger.Departing Thu, 24 Sep, returning Fri, 9 Oct.Return flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Thu, 24 Sep, arriving in London Heathrow.Inbound indirect flight with Icelandair, departs from London Heathrow on Fri, 9 Oct, arriving in Seattle / Tacoma International.Price includes taxes and charges.From £395, select.

London.£395 per passenger.Departing Tue, 14 Apr, returning Tue, 21 Apr.Return flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Tue, 14 Apr, arriving in London Heathrow.Inbound indirect flight with Icelandair, departs from London Heathrow on Tue, 21 Apr, arriving in Seattle / Tacoma International.Price includes taxes and charges.From £395, select.

London.£401 per passenger.Departing Tue, 28 Apr, returning Mon, 4 May.Return flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Tue, 28 Apr, arriving in London Heathrow.Inbound indirect flight with Icelandair, departs from London Heathrow on Mon, 4 May, arriving in Seattle / Tacoma International.Price includes taxes and charges.From £401, select.

London.£405 per passenger.Departing Wed, 6 May, returning Tue, 27 Oct.Return flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Wed, 6 May, arriving in London Heathrow.Inbound indirect flight with Icelandair, departs from London Heathrow on Tue, 27 Oct, arriving in Seattle / Tacoma International.Price includes taxes and charges.From £405, select.

London.£406 per passenger.Departing Thu, 7 May, returning Thu, 14 May.Return flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Thu, 7 May, arriving in London Heathrow.Inbound indirect flight with Icelandair, departs from London Heathrow on Thu, 14 May, arriving in Seattle / Tacoma International.Price includes taxes and charges.From £406, select.

London.£421 per passenger.Departing Thu, 22 Oct, returning Wed, 4 Nov.Return flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Thu, 22 Oct, arriving in London Heathrow.Inbound indirect flight with Icelandair, departs from London Heathrow on Wed, 4 Nov, arriving in Seattle / Tacoma International.Price includes taxes and charges.From £421, select.

London.£422 per passenger.Departing Tue, 10 Mar, returning Thu, 30 Apr.Return flight with Icelandair.Outbound indirect flight with Icelandair, departs from Seattle / Tacoma International on Tue, 10 Mar, arriving in London Heathrow.Inbound indirect flight with Icelandair, departs from London Heathrow on Thu, 30 Apr, arriving in Seattle / Tacoma International.Price includes taxes and charges.From £422, 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 March.

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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	£388
Cheapest month to fly	March
Average flight time	9 hrs, 35 mins
Most popular airline	KLM
Average flights per week	208

Check out these London Heathrow hotels

Ready to plan your stay? Other travellers rate these London Heathrow hotels for cleanliness, service and location.

Crowne Plaza London Heathrow T4 by IHG

0.94 miles from London Heathrow

£74

Per night

Holiday Inn Express London Heathrow T4 by IHG

0.96 miles from London Heathrow

£66

Per night

Renaissance London Heathrow Hotel

0.67 miles from London Heathrow

£89

Per night

Crowne Plaza London Heathrow T4 by IHG

0.94 miles from London Heathrow

£74

Per night

Holiday Inn Express London Heathrow T4 by IHG

0.96 miles from London Heathrow

£66

Per night

Renaissance London Heathrow Hotel

0.67 miles from London Heathrow

£89

Per night

Explore top-rated hotels

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 £388. 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 35 minutes is the average flight time from Seattle to London Heathrow.

Which airlines fly direct from Seattle to London Heathrow?

KLM, Virgin Atlantic and Delta fly direct from Seattle to London Heathrow.

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

As of February 2026, there are 208 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 March.

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, 9 March 2026.

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

Yes – the average flight time is 9 hours and 35 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 has a couple of airports that set the stage for your next getaway. Check out your options for booking a flight from Seattle to London Heathrow Airport (LHR) heading out from Seattle-Tacoma International Airport (SEA) or Lake Union Sea Plane Base Airport (LKE).
Jump on a direct Seattle to London Heathrow Airport flight and you'll be in the air for around 9 hours 35 minutes.
The timezone in London is UTC+0, which is seven hours ahead of Seattle. London Heathrow Airport is located in London.
The busiest route is from Seattle-Tacoma International Airport (SEA) to London Heathrow Airport (LHR), with 26 direct services every week. If you'd rather get moving right away, the earliest flight from SEA to LHR is the 1:30pm British Airways service. If a later flight fits your day better, the final departure is at 8:25pm with Delta Air Lines.
Leave enough time to make your flight from Seattle to LHR. As a general rule, arrive at least two hours before international departures and an hour ahead for domestic flights.
With more travellers during high season, plan to be at your terminal even earlier. Two hours for domestic flights and up to four for international journeys will allow for additional wait times.

Airports in Seattle

Seattle-Tacoma International Airport (SEA)

You can take a direct flight from Seattle to London Heathrow Airport (LHR) out of Seattle-Tacoma International Airport (SEA).
At SEA, you can choose from various carriers offering direct flights from Seattle to London Heathrow Airport, such as:
Most travellers prefer to fly with British Airways between SEA and LHR.
The carrier with the most consistent on-time arrivals rate on this route is Delta Air Lines.
Stopovers are the perfect opportunity to break up your journey and maybe even tour another city. When browsing cheap flights from Seattle to LHR departing from Seattle-Tacoma International Airport (SEA), uncheck the 'Direct flights only' box to find out where you can visit along the way. Top options include:
- 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 20 minutes by car, depending on traffic. The journey by public transport takes roughly 55 minutes.
Looking for a comfortable hotel close to Seattle-Tacoma International Airport? If you've booked an early flight from Seattle to London Heathrow Airport, these stays will have you sleeping moments from your departure gate:
81.27% of flights leaving Seattle-Tacoma International Airport land at their destination according to schedule. Given its strong performance rating, you're unlikely to face delays when jetting out of SEA.

Lake Union Sea Plane Base Airport (LKE)

You can arrive at LKE from central Seattle in about 10 minutes by car, depending on traffic conditions. The journey by public transport will take roughly 25 minutes to travel the 3 kms (2 miles) or so.
Want to enjoy an extra night away before boarding your Seattle to LHR flight? Check in to a hotel near Lake Union Sea Plane Base Airport before your trip officially starts. These stays have your key waiting:

About London Heathrow Airport (LHR)

The last thing you want is a lengthy journey to your hotel if you're arriving on a late flight from Seattle to London Heathrow Airport. Get comfy at one of these accommodation options near LHR instead:
Travel at your own speed with a London Heathrow Airport rental car. Pick up a set of wheels from Surprice, U-Save or Green Motion and venture far and wide through London and beyond.
Get the best deal by booking your vehicle around one week ahead of your Seattle to London Heathrow Airport flight.

Getting from London Heathrow Airport (LHR) to central London

London Heathrow Airport is about 16 miles from central London. How long it takes to get to the centre by car hire or cab will depend on the time of day. Do a little research before your trip.
If you're taking public transport, expect a journey time of about 1 hour.

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

£178 is the lowest price for a one-way ticket from Seattle to London Heathrow Airport. Return flights start at £388. These prices can change based on availability.
Score cheap flights from Seattle to LHR by booking six months ahead. According to our research, that's the ideal time frame for picking up a bargain.
Schedule your trip for November. That's the best month for landing the biggest deals on Seattle to London Heathrow Airport tickets. If you're flexible with your dates, use the 'Whole month' tool to find the cheapest price across every month.
You don't need to check every day to find out if fares have dropped when you set up a Price Alert. We'll let you know when a better deal comes up on plane tickets from Seattle to LHR.
Find the best deal on a flight from Seattle to London Heathrow Airport with the help of the filters. Choose your ideal arrival and departure times, number of stops and airlines. You can also sort your results by 'Cheapest,' 'Best' or 'Fastest.'

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

July is the busiest month for flights from Seattle to London Heathrow Airport (LHR). Visit London in February for a more laid-back experience.
Before locking in your Seattle to LHR plane ticket, consider what kind of weather works for you. July is the warmest month in London, with temperatures ranging from 11ºC (52ºF) to 26ºC (79ºF).
January sees temperatures of between 0ºC (32ºF) and 9ºC (48ºF). Search for cheap tickets from Seattle to London Heathrow Airport around that time if you like cooler conditions.

More about London

Start your London trip right by choosing the perfect place to stay. As soon as you've booked your flight from Seattle to London Heathrow Airport, explore our selection of hotels including:
All great holidays should include some sightseeing. The British Museum, Westminster Abbey and Big Ben are attractions you won't want to skip in London.

Explore more of the United Kingdom

Birmingham is just one of the many places in the United Kingdom waiting to be discovered once you've seen the sights of London. Around 153 kms (95 miles) away to the north-west, popular attractions include The Windsor Castle, Birmingham Museum & Art Gallery and Birmingham Hippodrome Theatre.
If you're ready to explore another corner of the United Kingdom, consider Bristol, about 145 kms (90 miles) west of London. Banksey, Banksy's You Don't Need Planning Permission to Build Castles in the Sky and Clifton Suspension Bridge are highlights.