Cheap flights from Washington, D.C. Dulles Intl Airport to London from £249

The cheapest month to fly to London from Washington, D.C. Dulles Intl Airport is in September. Flight prices, which tend to average around £475, are often lower during this time because this is during the off-season. The month of February is another great option to travel to London, with average flight prices from Washington, D.C. Dulles Intl Airport averaging around £485.

Our data shows that Sunday 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. Dulles Intl Airport to London for around £613.

The cheapest time of day to fly to London is in the afternoon when flights can be purchased for as low as £543. Flights in the evening are often more expensive, with an average ticket price of £592.

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

You are more likely to see cheaper flights to London 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 for around £579 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. Dulles Intl Airport for as low as £546 on momondo.

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

TAP AIR PORTUGAL, Icelandair, and United Airlines are the most popular carriers operating from Washington, D.C. Dulles Intl to London

British Airways, Virgin Atlantic and United Airlines are the top three most popular airlines that fly to London from Washington, D.C. Dulles Intl Airport according to our data. British Airways is the first choice among our users, with 44% 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 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 164 minutes.

Generally, flights departing in the morning tend to experience fewer delays. Flights departing in the early afternoon 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.

Reykjavik (KEF) was the most common stop: 63% of momondo users choosing one-stop flights on this route connected there.

Flights via Dublin (DUB) offer the lowest average return price of £399.

Flights connecting via Dublin (DUB) have the shortest average one-way travel time: 9h 50m.

Reykjavik (KEF) has the shortest average stopover time for this route: 1h 10m.

25 flights are operational daily from Washington, D.C. Dulles Intl Airport to London as of March 2026. The most popular departure time for this route is 19:00, with 100% of flights per day taking off in the evening.

As of March 2026, there are 178 flights per week flying from Washington, D.C. Dulles Intl Airport to London. The most common day of the week flights depart is Tue, with 15% of flights taking off on this day.