Cheap flights from London Heathrow Airport to Washington, D.C. from $348

The month of September is, on average, the cheapest month to fly to Washington, D.C. from London Heathrow Airport, with most prices found around $652. If you’re not able to fly to Washington, D.C. in September, then February is your next best option. Flight prices from London Heathrow Airport to Washington, D.C. during February average around $654.

On average, the least expensive day to fly to Washington, D.C. from London Heathrow Airport is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as $751. However, this price may fluctuate depending on the airline, the season, and holidays. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from London Heathrow Airport to Washington, D.C. for around $842.

In the afternoon is the cheapest time of day to fly from London Heathrow Airport to Washington, D.C. when you can find flight prices for as low as $770. Flying to Washington, D.C. in the afternoon is an ideal time because this is during off-peak travel hours. Try not to purchase tickets at noon because they tend to be around $810. Of course, these prices can vary depending on the time of year and what airport you fly to.

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

You are more likely to see cheaper flights to Washington, D.C. from London Heathrow Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Washington, D.C. for around $729 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Washington, D.C. from London Heathrow Airport for as low as $646 on momondo.

There are 3 cabin classes available to choose from on London Heathrow Airport to Washington, D.C. 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 2% on your flight if you consider stops on a London Heathrow Airport to Washington, D.C. flight.

As of October 2026, prices for London Heathrow Airport to Washington, D.C. flights are approximately 9% cheaper when compared to flights at the same time last year.

Icelandair, TAP AIR PORTUGAL, and Aer Lingus are the most popular carriers operating from London Heathrow to Washington, D.C.

British Airways, Lufthansa and United Airlines are the top three most popular airlines that fly to Washington, D.C. from London Heathrow Airport according to our data. British Airways is the first choice among our users, with 43% of people opting to fly with this airline when traveling to Washington, D.C.. Keep in mind that there are 10 different airlines that fly to Washington, D.C. on a routine basis, so you have a few additional options to choose from.

Historically, on average around 16% of flights between London and Washington, D.C. have experienced a delay on any given week. The average delay length over the past 12 months has been 140 minutes.

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

Saturday is statistically the day of the week which experiences the fewest number of delays on this flight route. Thursday has historically seen more delays on average compared to the rest of the week.

According to our data, United Airlines have had the least number of delays on this route over the last 12 months; with about 10% of their flights experiencing any sort of delay.

Dublin (DUB) was the most common stop: 43% of momondo users choosing 1-stop flights on this route connected there.

Flights via Amsterdam (AMS) offer the lowest average round-trip price of $598.

Flights connecting via Amsterdam (AMS) have the shortest average one-way travel time: 10h 40m.

Amsterdam (AMS) has the shortest average layover time for this route: 1h 10m.

36 flights are operational daily from London Heathrow Airport to Washington, D.C. as of October 2026. The most popular departure time for this route is 12:00PM, with 100% of flights per day taking off in the afternoon.

257 flights are operational weekly from London Heathrow Airport to Washington, D.C. as of October 2026. The most popular departure day for this route is Sat, with 16% of flights per week taking off on this day.