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Cheap flights from Washington, D.C. Dulles Intl Airport to London Heathrow Airport from C$ 512

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 7/2. Fares are subject to change and may not be available on all flights or dates of travel.
IAD — LHR
11 Jan — 18 Jan1
1 adult
1 adult, Economy, 0 bags

Cheapflights Tip: The best prices from Washington, D.C. Dulles Intl to London Heathrow are usually found in August or September, booked 45 days in advance, depart on a Thursday or Tuesday and return on a Tuesday

Cheap flight deals from Dulles Intl to Heathrow

Enter your travel dates to find the best prices.

Cheapest flights from Dulles Intl to Heathrow
Explore the most affordable flight options available from Dulles Intl to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 12 December 2025.

Tue 30/126:20 p.m.IAD - LHR
Nonstop7h 20mUnited Airlines
Tue 13/19:00 a.m.LHR - IAD
1 stop12h 40mUnited Airlines
Deal found 10/12C$ 834
Wed 31/125:06 p.m.IAD - LHR
1 stop11h 14mDelta
Thu 15/18:40 a.m.LHR - IAD
1 stop12h 25mDelta
Deal found 10/12C$ 841
Tue 30/126:05 p.m.IAD - LHR
1 stop11h 40mDelta
Thu 15/18:40 a.m.LHR - IAD
1 stop12h 25mDelta
Deal found 10/12C$ 850
Tue 30/126:20 p.m.IAD - LHR
Nonstop7h 20mUnited Airlines
Fri 9/17:00 a.m.LHR - IAD
1 stop12h 55mUnited Airlines
Deal found 10/12C$ 869
Wed 31/1210:15 p.m.IAD - LHR
Nonstop7h 35mUnited Airlines
Tue 13/112:05 p.m.LHR - IAD
Nonstop8h 30mUnited Airlines
Deal found 10/12C$ 873
Mon 29/1212:35 p.m.IAD - LHR
2 stops27h 00mUnited Airlines
Fri 9/17:00 a.m.LHR - IAD
1 stop12h 55mUnited Airlines
Deal found 11/12C$ 877
Wed 31/126:05 p.m.IAD - LHR
1 stop14h 45mDelta
Mon 12/110:00 a.m.LHR - IAD
1 stop11h 05mDelta
Deal found 10/12C$ 918
Mon 29/1210:33 p.m.IAD - LHR
1 stop26h 22mUnited Airlines
Wed 7/16:00 p.m.LHR - IAD
1 stop31h 26mUnited Airlines
Deal found 11/12C$ 923
Tue 30/1210:33 p.m.IAD - LHR
1 stop26h 22mUnited Airlines
Sat 10/19:00 a.m.LHR - IAD
2 stops35h 46mUnited Airlines
Deal found 10/12C$ 934

Find flight deals from Dulles Intl to Heathrow

Discover tips and strategies to find the most affordable flight options for your journey from Dulles Intl (IAD) to Heathrow (LHR). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 12 December 2025.

Round-trip from

C$ 787

One-way from

C$ 512

Popular in

June

Cheapest in

August

Average price

C$ 1,201
Scandinavian Airlines
  • Scandinavian Airlines
  • 19/3-23/3
  • 3 total stops
  • 27h 56m total
  • Washington, D.C. to London
Search Deals
TAP AIR PORTUGAL
  • TAP AIR PORTUGAL
  • 7/2
  • 1 total stop
  • 12h 55m total
  • Washington, D.C. to London
Search Deals
Highest demand for flights based on searches. 14% potential increase in price (C$ 236 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (C$ 46 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
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Cheapflights Fare Finder

 
Customize your flight search to find flights from Dulles Intl to Heathrow that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 629,999 searches. Data last updated 12 December 2025.
Use the filters below to find and compare flights from Washington, D.C. Dulles Intl Airport to London Heathrow Airport that are best for you.

Fly from

Dulles Intl

Fly to

Heathrow

Route

Depart

Return

Price

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Sat 24/1

12:23 p.m.-9:20 a.m.

2 stops15h 57m

London Heathrow

Sat 31/1

6:40 a.m.-6:50 p.m.

2 stops17h 10m

C$ 792

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Tue 24/3

1:19 p.m.-4:00 p.m.

2 stops22h 41m

London Heathrow

Tue 7/4

7:50 p.m.-4:50 p.m.

2 stops26h 00m

C$ 814

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Fri 6/2

12:23 p.m.-4:00 p.m.

2 stops22h 37m

London Heathrow

Mon 2/3

7:30 p.m.-7:09 p.m.

2 stops28h 39m

C$ 829

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Tue 30/12

6:20 p.m.-6:40 a.m.

Nonstop7h 20m

London Heathrow

Tue 13/1

9:00 a.m.-4:40 p.m.

1 stop12h 40m

C$ 834

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Tue 13/1

12:23 p.m.-4:00 p.m.

2 stops22h 37m

London Heathrow

Tue 20/1

7:50 p.m.-5:15 p.m.

2 stops26h 25m

C$ 841

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Tue 21/4

12:30 p.m.-4:25 p.m.

2 stops22h 55m

London Heathrow

Sat 2/5

10:20 a.m.-4:50 p.m.

1 stop11h 30m

C$ 843

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Fri 23/1

6:05 p.m.-6:40 a.m.

Nonstop7h 35m

London Heathrow

Mon 26/1

6:50 a.m.-2:35 p.m.

1 stop12h 45m

C$ 845

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Fri 9/1

6:20 p.m.-6:40 a.m.

Nonstop7h 20m

London Heathrow

Fri 16/1

1:45 p.m.-4:40 p.m.

1 stop31h 55m

C$ 845

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Mon 16/3

7:20 p.m.-6:40 a.m.

Nonstop7h 20m

London Heathrow

Wed 25/3

11:10 a.m.-9:05 p.m.

1 stop13h 55m

C$ 845

Washington, D.C.London

IAD - LHR

IADLHR

Washington, D.C. Dulles Intl

Tue 10/3

7:20 p.m.-6:40 a.m.

Nonstop7h 20m

London Heathrow

Fri 20/3

1:45 p.m.-5:40 p.m.

1 stop31h 55m

C$ 845

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/12

Showing 1-10 of 22 results
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Best time to book a flight from Dulles Intl to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Dulles Intl with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Washington, D.C. Dulles Intl Airport to London Heathrow Airport

How far ahead should I book a flight from Washington, D.C. Dulles Intl Airport to London Heathrow Airport?

Use this chart to determine the optimal time to book a round-trip flight from Dulles Intl to Heathrow. Price data was last updated on 5 December 2025.

The price you pay for your flight from Washington, D.C. Dulles Intl Airport to London Heathrow Airport may vary depending on when you book. For the best chance of a lower fare, look to book 45 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to London Heathrow Airport?

Currently, August is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to London Heathrow Airport (average of C$ 600). Flying from Washington, D.C. Dulles Intl Airport to London Heathrow Airport in June is currently the most expensive (average of C$ 1,027). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from IAD to LHR?

Find hourly flight availability from Dulles Intl to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 12 December 2025.

When flying from Washington, D.C. Dulles Intl Airport to London Heathrow Airport, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Related info for your journey

Find useful and relevant information for your journey from Dulles Intl to Heathrow. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Washington, D.C. Dulles Intl Airport to London Heathrow Airport?

    There are many flights that can get you from Washington, D.C. Dulles Intl Airport to London Heathrow Airport in 7h 20m. Fly via Scandinavian Airlines or United Airlines to get the fastest option. There are 5897 km between Washington, D.C. Dulles Intl Airport and London Heathrow Airport. This flight may include one or multiple stops.

  • What are the most reliable airlines from Washington, D.C. Dulles Intl Airport to London Heathrow Airport?

    No one likes to see their flight delayed. When booking a flight from Washington, D.C. Dulles Intl Airport to London Heathrow Airport consider choosing Air France (90%), Delta (90%) or Virgin Atlantic (90%) as they are the most reliable in getting you off to your destination on time.

  • Can I find deals for flights from Dulles Intl to Heathrow that include hotel bookings?

    Yes. In addition to deals on Dulles Intl to Heathrow flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Dulles Intl to Heathrow?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Dulles Intl to Heathrow.

  • Can I find deals for business class flights from Dulles Intl to Heathrow?

    Yes. Cheapflights offers flight deals from Dulles Intl to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to London Heathrow Airport?

    Currently, August is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to London Heathrow Airport (average of C$ 600). Flying from Washington, D.C. Dulles Intl Airport to London Heathrow Airport in June is currently the most expensive (average of C$ 1,027). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Travelling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Sutton
Twickenham
Slough
Marlow
Milton Keynes
Leamington Spa
Romford
Watford
Bedford
Luton
Stratford-upon-Avon
Gatwick
Hounslow

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