Cheap flights from Washington, D.C. to London from £187

The cheapest month to fly to London from Washington, D.C. is in October. Flight prices, which tend to average around £452, are often lower during this time because this is during the off-season. The month of August is another great option to travel to London, with average flight prices from Washington, D.C. averaging around £472.

Our data shows that Tuesday is the least expensive day to fly to London. Tickets to fly out on this day can be as low as £543. When flying out on a Friday, the most expensive travel day of the week, you can expect to see flight prices from Washington, D.C. to London for around £598.

The cheapest time of day to fly to London is in the afternoon when flights can be purchased for as low as £524. Flights in the evening are often more expensive, with an average ticket price of £595.

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 £588 when searching weeks before you fly. 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 £524 on momondo.

You could potentially save up to 49% on your flight if you consider stops on a Washington, D.C. to London flight.

As of May 2026, prices for Washington, D.C. to London flights are approximately 37% more expensive when compared to flights at the same time last year.

Icelandair, JetBlue, and SWISS are the most popular carriers operating from Washington, D.C. to London

British Airways, Virgin Atlantic and United 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 52% of people opting to fly with this airline when travelling to London. Keep in mind that there are 6 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 170 minutes.

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

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

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

Dublin (DUB) was the most common stop: 29% of momondo users choosing one-stop flights on this route connected there.

Flights via Reykjavik (KEF) offer the lowest average return price of £332.

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

New York (JFK) has the shortest average stopover time for this route: 1h 22m.

32 flights are operational daily from Washington, D.C. to London as of May 2026. The most popular departure time for this route is 21:00, with 83% of flights per day taking off in the evening.

230 flights are operational weekly from Washington, D.C. to London as of May 2026. The most popular departure day for this route is Fri, with 15% of flights per week taking off on this day.