Cheap flights from Washington to London from £249

In general, January is the cheapest month to fly from State of Washington to London Heathrow Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around £519. The month of February is another great option to travel to London Heathrow Airport, with average flight prices from State of Washington averaging around £529.

On average, the least expensive day to fly to London Heathrow Airport from State of Washington is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as £646. However, this price may fluctuate depending on the airline, the season, and holidays. Be sure to avoid booking your departure on a Sunday as prices are generally higher than usual. According to our data, the average ticket price to London Heathrow Airport on Sunday is £742.

According to our data, the cheapest time of day to fly to London Heathrow Airport is at midday. momondo users have found flights departing from State of Washington to London Heathrow Airport at midday for as low as £646. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. If you have a flexible travel schedule, then try to avoid flying in the evening when prices are £726 on average. Flights to London Heathrow Airport from State of Washington in the evening are generally more expensive because this time of day is more convenient for travellers’ schedules.

Fly from Seattle/Tacoma Intl to London Heathrow for the best Washington - London Heathrow flight prices

You are more likely to see cheaper flights to London Heathrow Airport from State of Washington when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around £664 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from State of Washington for as low as £620 on momondo.

There are 3 cabin classes available to choose from on State of Washington 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.

United Airlines, Alaska Airlines, and British Airways are the most popular carriers operating from Washington to London Heathrow

Virgin Atlantic, British Airways and Alaska Airlines are the top three most popular airlines that fly to London Heathrow Airport from State of Washington according to our data. Virgin Atlantic is the first choice among our users, with 51% of people opting to fly with this airline when travelling to London Heathrow Airport. Keep in mind that there are 3 different airlines that fly to London Heathrow Airport on a routine basis, so you have a few additional options to choose from.

The number of flights available between State of Washington and London Heathrow Airport is 24 per day as of September 2026. The most frequent departure time is 21:00, with 55% of daily flights leaving in the evening.

As of September 2026, 172 flights take off from State of Washington and land in London Heathrow Airport each week. The most common flight departure day for this route is Tue, with 15% of weekly flights taking off on this day.