Cheap flights from Washington, D.C. Dulles Intl Airport to London Heathrow Airport from C$ 491
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 8/12. Fares are subject to change and may not be available on all flights or dates of travel.
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 Saturday and return on a Tuesday
Cheap 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 27 October 2025.
Round-trip from | C$ 791 |
|---|---|
One-way from | C$ 491 |
Popular in | June |
Cheapest in | August |
Average price | C$ 960 |
Good round-trip deal | C$ 1,324 or less |
Find flight deals from Dulles Intl to Heathrow
Cheapest flights from Dulles Intl to HeathrowExplore 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 27 October 2025.
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 27 October 2025.
Cheapflights Fare Finder
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
Fly to
Route
Depart
Return
Price
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Sun 15/2
12:30 p.m.-5:40 p.m.
2 stops24h 10m
London Heathrow
Sat 21/2
6:40 a.m.-6:50 p.m.
2 stops17h 10m
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Tue 2/12
10:20 p.m.-10:50 a.m.
Nonstop7h 30m
London Heathrow
Wed 10/12
9:00 a.m.-4:35 p.m.
1 stop12h 35m
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Wed 12/11
10:20 p.m.-10:50 a.m.
Nonstop7h 30m
London Heathrow
Wed 19/11
9:00 a.m.-4:35 p.m.
1 stop12h 35m
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Sun 16/11
10:20 p.m.-10:50 a.m.
Nonstop7h 30m
London Heathrow
Thu 11/12
10:00 a.m.-4:05 p.m.
1 stop11h 05m
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Mon 17/11
10:20 p.m.-10:50 a.m.
Nonstop7h 30m
London Heathrow
Thu 11/12
10:00 a.m.-4:05 p.m.
1 stop11h 05m
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Tue 18/11
10:20 p.m.-10:50 a.m.
Nonstop7h 30m
London Heathrow
Fri 12/12
4:50 p.m.-8:30 p.m.
Nonstop8h 40m
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Fri 23/1
12:30 p.m.-9:20 a.m.
2 stops15h 50m
London Heathrow
Fri 15/5
6:40 a.m.-4:50 p.m.
2 stops15h 10m
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Mon 29/12
10:20 p.m.-10:50 a.m.
Nonstop7h 30m
London Heathrow
Fri 9/1
8:55 a.m.-6:42 p.m.
1 stop14h 47m
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Wed 26/11
6:03 a.m.-7:05 a.m.
1 stop20h 02m
London Heathrow
Tue 2/12
5:35 p.m.-4:35 p.m.
1 stop28h 00m
Washington, D.C.London
IAD - LHR
IADLHR
Washington, D.C. Dulles Intl
Sun 15/3
7:20 p.m.-6:40 a.m.
Nonstop7h 20m
London Heathrow
Mon 30/3
7:10 p.m.-7:25 p.m.
1 stop29h 15m
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.
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?
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$ 606). Flying from Washington, D.C. Dulles Intl Airport to London Heathrow Airport in June is currently the most expensive (average of C$ 1,047). 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?
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.
How often are flights from Washington, D.C. to London delayed?
About 24% of weekly flights between Washington, D.C. and London have experienced delays in the past year, with the average delay time being 159 minutes.
What is the most punctual flight time for Washington, D.C. to London flights?
Historically, flights departing in the early afternoon are less likely to be delayed, whereas flights leaving in the morning tend to experience delays more often.
What day of the week experiences the fewest flight delays on this route?
Monday tends to have the lowest number of delays on this route, whereas Thursday has historically faced a higher average of delays compared to other days of the week.
Which airline has the best punctuality record on Washington, D.C. to London flights?
Over the past year, Aeromexico has had the lowest number of delays on this route, with no flights being classified as delayed.
Related info for your journey
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