$231 Cheap Flights from Washington (IAD) to London (LHR)

View $231 flight on Sun, Sep 21, 2025Opens in a new window

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

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Cheap Flights from Washington to London (IAD-LHR)

Prices were available within the past 7 days and start at $231 for one-way flights and $450 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

TAP Portugal
Tue, Oct 14 - Wed, Oct 22
IAD
Washington
LHR
London
$450 Roundtrip, just found
$450
Roundtrip
just found
Select TAP Portugal flight, departing Tue, Oct 14 from Washington to London, returning Wed, Oct 22, priced at $450 just found
Icelandair
Mon, Feb 16 - Sun, Feb 22
IAD
Washington
LHR
London
$474 Roundtrip, found 9 hours ago
$474
Roundtrip
found 9 hours ago
Select Icelandair flight, departing Mon, Feb 16 from Washington to London, returning Sun, Feb 22, priced at $474 found 9 hours ago
Aer Lingus
Wed, Aug 6 - Tue, Nov 4
IAD
Washington
LHR
London
$481 Roundtrip, found 20 hours ago
$481
Roundtrip
found 20 hours ago
Select Aer Lingus flight, departing Wed, Aug 6 from Washington to London, returning Tue, Nov 4, priced at $481 found 20 hours ago
Scandinavian Airlines
Mon, Feb 16 - Sun, Feb 22
IAD
Washington
LHR
London
$484 Roundtrip, found 9 hours ago
$484
Roundtrip
found 9 hours ago
Select Scandinavian Airlines flight, departing Mon, Feb 16 from Washington to London, returning Sun, Feb 22, priced at $484 found 9 hours ago
Swiss International Air Lines
Tue, Sep 9 - Mon, Sep 22
IAD
Washington
LHR
London
$519 Roundtrip, found 12 hours ago
$519
Roundtrip
found 12 hours ago
Select Swiss International Air Lines flight, departing Tue, Sep 9 from Washington to London, returning Mon, Sep 22, priced at $519 found 12 hours ago
Air Canada
Wed, Nov 12 - Tue, Nov 25
IAD
Washington
LHR
London
$524 Roundtrip, found 12 hours ago
$524
Roundtrip
found 12 hours ago
Select Air Canada flight, departing Wed, Nov 12 from Washington to London, returning Tue, Nov 25, priced at $524 found 12 hours ago
Lufthansa
Wed, Nov 12 - Tue, Nov 25
IAD
Washington
LHR
London
$548 Roundtrip, found 12 hours ago
$548
Roundtrip
found 12 hours ago
Select Lufthansa flight, departing Wed, Nov 12 from Washington to London, returning Tue, Nov 25, priced at $548 found 12 hours ago
Iberia
Mon, Feb 16 - Sun, Feb 22
IAD
Washington
LHR
London
$565 Roundtrip, found 9 hours ago
$565
Roundtrip
found 9 hours ago
Select Iberia flight, departing Mon, Feb 16 from Washington to London, returning Sun, Feb 22, priced at $565 found 9 hours ago
United
Sun, Dec 28 - Tue, Dec 30
IAD
Washington
LHR
London
$592 Roundtrip, just found
$592
Roundtrip
just found
Select United flight, departing Sun, Dec 28 from Washington to London, returning Tue, Dec 30, priced at $592 just found
British Airways
Mon, Oct 20 - Tue, Nov 4
IAD
Washington
LHR
London
$615 Roundtrip, just found
$615
Roundtrip
just found
Select British Airways flight, departing Mon, Oct 20 from Washington to London, returning Tue, Nov 4, priced at $615 just found

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

October is typically the cheapest month to fly

From $450 - $805 per traveler.

Graph displaying average flight prices per month

Alternative airports near London

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Gatwick LGW. Average driving time to city center is 52 minutes. Flights from $617
LGW
Gatwick
Average driving time to city center52 min
Flights from $617
Select flight to London City LCY. Closest option available. Average driving time to city center is 21 minutes. Flights from $669
LCY
London City
Closest
Average driving time to city center21 min
Flights from $669
Flights from Washington (IAD) to London (LHR)
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
Roundtrip price
$450
Distance
3666 mi
Average flight time
12 hours 23 mins

Washington to London Flights

The cheapest times to fly from Washington to London

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Washington to London are during the month of October. You can find some of the cheapest flights from Washington to London with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Washington to London

Sunday is one of the best days to book for cheap flights from Washington to London: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Washington to London

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Washington to London in 2025. You can also book with separate airlines for your outbound and return journeys, from $231 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Washington to London flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Washington to London airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR) cost?
Snag cheap return fares starting from $515 from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR). This information is based on the cheapest price found on Expedia for this return journey departing within the next three months. This airfare is for a Delta flight leaving IAD on August 19 2025 and touching down at LHR. The price was last updated on July 23 2025 and has not changed since.
What is the cheapest month to fly from IAD to LHR?
The cheapest flights from IAD to LHR are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
Which airlines fly direct from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR)?
Skip the layovers and fly direct to Heathrow Airport (LHR) from Washington Dulles Intl. Airport (IAD) with 3 carriers, including:

  • British Airways
  • United Airlines
  • Virgin Atlantic

What is the cheapest airline that flies from IAD to LHR?
With prices starting from $384 for a one-way flight from IAD to LHR, United is currently the cheapest airline flying this route. This fare is based on the lowest price found on Expedia departing within the next three months. The flight takes off from IAD on October 15 2025. Prices were last updated on July 23 2025 and have not changed since.
How many flights per day from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR)?
When flying out of Washington Dulles Intl. Airport (IAD), you can take your pick from an average of 4 daily direct flights to Heathrow Airport (LHR).
What are the most popular departure times for flights from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR)?
The 6 PM departures from IAD to LHR are the most sought after. Prices can be higher for these popular slots. If you want to save on your trip, book during off-peak hours.
What day of the week has the most flights from IAD to LHR?
Depart on a Friday if you're looking for the best selection of flights from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR).
What is the earliest flight from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR)?
The earliest flight taking off from Washington Dulles Intl. Airport (IAD) is at around 6:00PM UTC-5. Board this plane and you'll touch down at Heathrow Airport (LHR) at approximately 6:15AM UTC+0. The entire trip takes 7h 15m.
How long does it take to fly from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR)?
The average flight duration from IAD to LHR is 7 hours and 17 minutes, covering a distance of 3,700 mi.
What airline has the least delays from IAD to LHR?
With 80% of journeys typically arriving as scheduled, American Airlines has the best on-time performance for nonstop flights from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR). To check your flight status and receive notifications if anything changes, use the Expedia App.
What is the best time to fly from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR)?
To avoid possible delays on the Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR) route, aim to fly before 3 PM. Departures after this time are 22% more likely to be canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for London from Washington Dulles Intl. Airport (IAD)?
Heathrow Airport (LHR) is the only airport in London with direct flights from Washington Dulles Intl. Airport (IAD). Compare your options and discover affordable fares on Expedia.
Is it cheaper to buy a plane ticket from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR) last-minute?
Booking your ticket from IAD to LHR just before your trip is typically more expensive. However, if there's some wiggle room with your itinerary, you could grab a cheap last-minute fare.
Is it cheaper to book an IAD to LHR flight and hotel package?
You can save money by booking an IAD to LHR flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it's simple to manage everything in one place. After selecting your preferred accommodations and flights, consider adding extras like tours, car rentals and activities.
Can I cancel or change the date of my flight from Washington Dulles Intl. Airport (IAD) to Heathrow Airport (LHR)?
You can usually cancel or reschedule your IAD to LHR flight. However, for bookings made more than 24 hours ago, additional fees may apply. Refer to your airline's policies in your itinerary to see what changes are possible and whether any costs are involved. You'll also find more information on our Customer Service portal.

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