Cheap flights from Washington, D.C. to London from $330

The month of August is, on average, the cheapest month to fly to London Heathrow Airport from Washington, D.C., with most prices found around $658. If you’re not able to fly to London Heathrow Airport in August, then February is your next best option. Flight prices from Washington, D.C. to London Heathrow Airport during February average around $671.

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 $765. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $891.

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. to London Heathrow Airport in the afternoon for as low as $814. 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 $841.

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

You are more likely to see cheaper flights to London Heathrow Airport from Washington, D.C. when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around $784 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. for as low as $731 on momondo.

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

You could potentially save up to 20% on your flight if you consider stops on a Washington, D.C. to London Heathrow Airport flight.

As of April 2026, prices for Washington, D.C. to London Heathrow Airport flights are approximately 24% more expensive when compared to flights at the same time last year.

TAP AIR PORTUGAL, KLM, and Delta are the most popular carriers operating from Washington, D.C. to London Heathrow

British Airways, United Airlines and American Airlines are the top three most popular airlines that fly to London Heathrow Airport from Washington, D.C. according to our data. British Airways is the first choice among our users, with 56% of people opting to fly with this airline when traveling to London Heathrow Airport. Keep in mind that there are 18 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 168 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. Friday has historically seen more delays on average compared to the rest of the week.

According to our data, British Airways 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: 33% of momondo users choosing 1-stop flights on this route connected there.

Flights via Lisbon (LIS) offer the lowest average round-trip price of $520.

Flights connecting via Dublin (DUB) have the shortest average one-way travel time: 9h 39m.

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

32 flights are operational daily from Washington, D.C. to London Heathrow Airport as of April 2026. The most popular departure time for this route is 10:00PM, with 85% of flights per day taking off in the evening.

As of April 2026, there are 224 flights per week flying from Washington, D.C. to London Heathrow Airport. The most common day of the week flights depart is Mon, with 15% of flights taking off on this day.