Cheap flights from Washington, D.C. to London from $345

The month of January is, on average, the cheapest month to fly to London Heathrow Airport from Washington, D.C., with most prices found around $281. If you’re not able to fly to London Heathrow Airport in January, then February is your next best option. Flight prices from Washington, D.C. to London Heathrow Airport during February average around $478.

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 $782. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $915.

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 $822. 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 $875.

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 $807 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 $718 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 28% on your flight if you consider stops on a Washington, D.C. to London Heathrow Airport flight.

As of May 2026, prices for Washington, D.C. to London Heathrow Airport flights are approximately 1% cheaper when compared to flights at the same time last year.

Icelandair, TAP AIR PORTUGAL, and KLM 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 55% 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 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 169 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.

33 flights are operational daily from Washington, D.C. to London Heathrow Airport as of May 2026. The most popular departure time for this route is 10:00PM, with 84% of flights per day taking off in the evening.

As of May 2026, there are 231 flights per week flying from Washington, D.C. to London Heathrow Airport. The most common day of the week flights depart is Mon, with 14% of flights taking off on this day.