Cheap flights from Washington, D.C. to London from $218

The cheapest month to fly to London from Washington, D.C. is in August. Flight prices, which tend to average around $678, are often lower during this time because this is during the off-season. The month of September is another great option to travel to London, with average flight prices from Washington, D.C. averaging around $687.

The cheapest day to depart from Washington, D.C. to London is on a Wednesday. Travelers who choose to depart for London on a Wednesday will often find tickets for as low as $789. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $922. These prices are subject to change though, so be sure to set up a Price Alert for flights to London.

Flying to London from Washington, D.C. in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $825 when looking at flights departing in the afternoon. Flights to London are more costly in the evening, with an average ticket price of $888. Departure times in the evening fall within the peak daily travel times, which is why tickets can be more expensive.

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

You are more likely to see cheaper flights to London from Washington, D.C. when booking weeks ahead of your departure date. In general, you can expect to find flights to London for around $821 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London 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 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 34% on your flight if you consider stops on a Washington, D.C. to London flight.

As of June 2026, prices for Washington, D.C. to London flights are approximately 43% more expensive when compared to flights at the same time last year.

Delta, Virgin Atlantic, and Icelandair are the most popular carriers operating from Washington, D.C. to London

British Airways, United Airlines and American Airlines are the top three most popular airlines that fly to London from Washington, D.C. according to our data. British Airways is the first choice among our users, with 54% of people opting to fly with this airline when traveling to London. Keep in mind that there are 18 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.

Historically, on average around 19% 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 171 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: 44% of momondo users choosing 1-stop flights on this route connected there.

Flights via Lisbon (LIS) offer the lowest average round-trip price of $445.

Flights connecting via New York (JFK) have the shortest average one-way travel time: 9h 34m.

New York (JFK) has the shortest average layover time for this route: 1h 18m.

32 flights are operational daily from Washington, D.C. to London as of June 2026. The most popular departure time for this route is 10:00PM, with 92% of flights per day taking off in the evening.

As of June 2026, there are 225 flights per week flying from Washington, D.C. to London. The most common day of the week flights depart is Mon, with 15% of flights taking off on this day.