£172 Cheap Flights from Washington (IAD) to London (LHR)

View £172 flight on Sat, 4 Oct 2025Opens in a new window

Popular airlines from Washington Dulles International Airport (IAD) to Heathrow Airport (LHR)

  • Plan, book, fly with confidence

  • trending down icon

    Be in the know

    Get alerts if flight prices drop or rise*
  • bex rewards loyalty icon

    Book smarter

    Save up to 25% on select hotels after you book a flight*
  • payments icon

    Earn twice

    Earn your airline miles on top of our rewards
    Sign in

Cheap Flights from Washington (IAD) to London (LHR)

Prices were available within the past 7 days and start at £172 for one-way flights and £333 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

TAP Portugal
Thu, 15 Jan - Wed, 28 Jan
IAD
Washington
LHR
London
£333 Return, found 3 days ago
£333
Return
found 3 days ago
Select TAP Portugal flight, departing Thu, 15 Jan from Washington to London, returning Wed, 28 Jan, priced at £333 found 3 days ago
Aer Lingus
Mon, 4 Aug - Wed, 27 Aug
IAD
Washington
LHR
London
£359 Return, found 21 hours ago
£359
Return
found 21 hours ago
Select Aer Lingus flight, departing Mon, 4 Aug from Washington to London, returning Wed, 27 Aug, priced at £359 found 21 hours ago
United
Sun, 3 Aug - Wed, 20 Aug
IAD
Washington
LHR
London
£374 Return, found 1 day ago
£374
Return
found 1 day ago
Select United flight, departing Sun, 3 Aug from Washington to London, returning Wed, 20 Aug, priced at £374 found 1 day ago
Iberia
Wed, 19 Nov - Wed, 3 Dec
IAD
Washington
LHR
London
£375 Return, found 1 day ago
£375
Return
found 1 day ago
Select Iberia flight, departing Wed, 19 Nov from Washington to London, returning Wed, 3 Dec, priced at £375 found 1 day ago
British Airways
Sun, 14 Sep - Mon, 22 Sep
IAD
Washington
LHR
London
£375 Return, found 17 hours ago
£375
Return
found 17 hours ago
Select British Airways flight, departing Sun, 14 Sep from Washington to London, returning Mon, 22 Sep, priced at £375 found 17 hours ago
Virgin Atlantic
Mon, 1 Dec - Wed, 10 Dec
IAD
Washington
LHR
London
£377 Return, found 14 hours ago
£377
Return
found 14 hours ago
Select Virgin Atlantic flight, departing Mon, 1 Dec from Washington to London, returning Wed, 10 Dec, priced at £377 found 14 hours ago
Virgin Atlantic
Mon, 1 Dec - Wed, 10 Dec
IAD
Washington
LHR
London
£382 Return, found 14 hours ago
£382
Return
found 14 hours ago
Select Virgin Atlantic flight, departing Mon, 1 Dec from Washington to London, returning Wed, 10 Dec, priced at £382 found 14 hours ago
Icelandair
Mon, 1 Dec - Wed, 10 Dec
IAD
Washington
LHR
London
£386 Return, found 14 hours ago
£386
Return
found 14 hours ago
Select Icelandair flight, departing Mon, 1 Dec from Washington to London, returning Wed, 10 Dec, priced at £386 found 14 hours ago
Lufthansa
Fri, 24 Oct - Sun, 26 Oct
IAD
Washington
LHR
London
£396 Return, found 4 days ago
£396
Return
found 4 days ago
Select Lufthansa flight, departing Fri, 24 Oct from Washington to London, returning Sun, 26 Oct, priced at £396 found 4 days ago
Delta
Mon, 15 Sep - Wed, 1 Oct
IAD
Washington
LHR
London
£401 Return, found 1 day ago
£401
Return
found 1 day ago
Select Delta flight, departing Mon, 15 Sep from Washington to London, returning Wed, 1 Oct, priced at £401 found 1 day ago

Find the cheapest month to fly from Washington (IAD) to London (LHR)

October is typically the cheapest month to fly

From £336 - £601 per traveller.

Graph displaying average flight prices per month

Flight from Washington to London route information
Origin airport
Washington Dulles Intl.
Destination airport
Heathrow
Airlines serving
Aer Lingus, Air Canada, Air France, American Airlines, Austrian Airlines, British Airways, Brussels Airlines, Delta, Finnair, Iberia, Icelandair, KLM, Lufthansa, Royal Air Maroc, Scandinavian Airlines, Swiss International Air Lines, TAP Portugal, Turkish Airlines, United, Virgin Atlantic
Return price
£332
Distance
5866 km
Average flight time
12 hours 23 mins

Compare flights from Washington to London easily and book with confidence

For travelling on business or for pleasure, Expedia makes it easy to book your flights from Washington to London. Operating between them flights per day, 20 airlines cover the route. And fly direct, getting you to Heathrow in just hours. If you have a preferred carrier, use our advanced search tool to find the right flight from Washington Dulles Intl. to Heathrow.  

To make things even better, in the advanced search, you can also choose to fly economy, premium economy, business or first class, select your maximum number of stops, and pick your preferred departure and arrival time. You can also opt for refundable and direct flights. 

Grab a great deal on your flight from Washington Dulles Intl. (IAD) to Heathrow (LHR)

The easiest way to view the best deals on flights from Washington to London today is to enter your travel dates and hit search. From here, you can sort your results by price to see the cheapest flights first. Right now, return flights from Washington Dulles Intl. to Heathrow start at just £333 and range up to £401.  

To find an even better deal, try  

  • being flexible on your dates – midweek flights can be cheaper
  • looking for other airports near Washington and London
  • booking your flight during January, the cheapest month on this route
  • varying your flight times – early morning and late at night are sometimes cheaper 

Why you should book your Washington to London flight with Expedia!

We cater for all flight types, cabin classes and airlines. So whether you’re booking flights from Washington Dulles Intl. to Heathrow for a budget break or a business trip with a bit of pleasure thrown in, we make it easy to secure the seat that’s right for you.  

Thanks to our supersized inventory that offers great choice all in one place, you know you’ll get a great deal with Expedia. Especially if you bundle your flight together with your hotel, you will unlock amazing savings. For added peace of mind, you can choose flexible bookings or filter to find refundable options, so you won’t pay a fee to change your flight.  

Frequently asked questions

How much is a flight from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR)?
Start packing your suitcase, because round-trip journeys from IAD to London Heathrow start from £333. That's based on airfares listed within the last 7 days on Expedia for flights departing within the next year. Prices can change quickly, so book today to nab the best deal. Prices and availability are subject to change. Additional terms apply.
Do I need to pay a cancellation fee if I cancel my flight from Dulles Intl. Airport to Heathrow Airport?
We understand that things come up unexpectedly, so we've made it as easy as possible for you to cancel your trip online. Just head to the Customer Service Portal and follow the instructions.
How do I find cheap flights from Dulles Intl. Airport to Heathrow Airport (LHR) that have flexible change policies?
Many airlines offer the option to reschedule your flight without a change fee. All you pay is the difference between the original flight and the new flight. When you're searching for IAD to Heathrow Airport flights, you'll see a "no change fees" filter for you to select.
How far is the flight from Dulles Intl. Airport to LHR?
You'll have 5,900 kilometres to cover on the long-haul Chantilly to Hounslow route. Dress in layers of comfortable clothes and consider taking a sleep mask and earplugs.
Which airlines fly direct from Washington Dulles Intl. Airport (IAD) to Heathrow Airport?
With 60 flights a month from Dulles Intl. Airport to LHR, United Airlines (UA) is an excellent choice. Another carrier operating on this route is British Airways (BA). You'll have 60 flights every month to choose from.
Are IAD to LHR flight tickets cheaper when they're purchased at the last minute?
Booking your trip from IAD to London Heathrow at the last minute could be your ticket to a great deal. However, it could end up costing a great deal more! If you'd prefer to err on the side of caution, book well ahead of your departure date. In fact, Expedia has some of the biggest bargains up to a year in advance. If your preferred carrier hasn't released tickets yet, check back regularly as deals are updated on Expedia all the time.

Explore a world of travel with Expedia

*Available to Expedia members.