Cheap flights from Washington, D.C. Dulles Intl Airport to London from $331

The month of August is, on average, the cheapest month to fly to London Heathrow Airport from Washington, D.C. Dulles Intl Airport, with most prices found around $666. If you’re not able to fly to London Heathrow Airport in August, then October is your next best option. Flight prices from Washington, D.C. Dulles Intl Airport to London Heathrow Airport during October average around $683.

Our data shows that Wednesday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $757. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $884.

According to our data, the cheapest time of day to fly to London Heathrow Airport is in the afternoon. momondo users have found flights departing from Washington, D.C. Dulles Intl Airport to London Heathrow Airport in the afternoon for as low as $807. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the evening are often more expensive with an average ticket price of $814.

Fly from Washington, D.C. Dulles Intl to London Heathrow for the best Washington, D.C. Dulles Intl - London Heathrow flight prices

You are more likely to see cheaper flights to London Heathrow Airport from Washington, D.C. Dulles Intl Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around $759 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from Washington, D.C. Dulles Intl Airport for as low as $711 on momondo.

There are 4 cabin classes available to choose from on Washington, D.C. Dulles Intl to London Heathrow flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

No. A direct flight is the cheapest option for a flight between Washington, D.C. Dulles Intl Airport to London Heathrow Airport.

As of February 2026, prices for Washington, D.C. Dulles Intl Airport to London Heathrow Airport flights are approximately 63% more expensive when compared to flights at the same time last year.

TAP AIR PORTUGAL is the most popular carrier operating from Washington, D.C. Dulles Intl to London Heathrow

British Airways, United Airlines and Iberia are the top three most popular airlines that fly to London Heathrow Airport from Washington, D.C. Dulles Intl Airport according to our data. British Airways is the first choice among our users, with 50% of people opting to fly with this airline when traveling to London Heathrow Airport. Keep in mind that there are 17 different airlines that fly to London Heathrow Airport on a routine basis, so you have a few additional options to choose from.

Historically, on average around 20% of flights between Washington, D.C. and London have experienced a delay on any given week. The average delay length over the past 12 months has been 163 minutes.

Generally, flights departing at night tend to experience fewer delays. Flights in the morning have, in the past, seen delays more frequently in comparison.

Monday is statistically the day of the week which experiences the fewest number of delays on this flight route. Saturday has historically seen more delays on average compared to the rest of the week.

According to our data, Virgin Atlantic have had the least number of delays on this route over the last 12 months; with about 15% of their flights experiencing any sort of delay.

Reykjavik (KEF) was the most common stop: 47% of momondo users choosing 1-stop flights on this route connected there.

Flights via Lisbon (LIS) offer the lowest average round-trip price of $449.

Flights connecting via Dublin (DUB) have the shortest average one-way travel time: 9h 40m.

Zurich (ZRH) has the shortest average layover time for this route: 1h 23m.

23 flights are operational daily from Washington, D.C. Dulles Intl Airport to London Heathrow Airport as of February 2026. The most popular departure time for this route is 6:00PM, with 100% of flights per day taking off in the evening.

As of February 2026, 164 flights take off from Washington, D.C. Dulles Intl Airport and land in London Heathrow Airport each week. The most common flight departure day for this route is Wed, with 16% of weekly flights taking off on this day.