Cheap flights from Washington to London from £248

The cheapest month to fly to London from State of Washington is in January. Flight prices, which tend to average around £509, 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 State of Washington averaging around £540.

Our data shows that Wednesday is the least expensive day to fly to London. Tickets to fly out on this day can be as low as £644. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from State of Washington to London for around £739.

The cheapest time of day to fly to London is at midday when flights can be purchased for as low as £644. Flights in the evening are often more expensive, with an average ticket price of £723.

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

You are more likely to see cheaper flights to London from State of Washington when booking weeks ahead of your departure date. In general, you can expect to find flights to London for around £661 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 State of Washington for as low as £617 on momondo.

There are 3 cabin classes available to choose from on State of Washington to London 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 SWISS are the most popular carriers operating from Washington to London

Virgin Atlantic, British Airways and Alaska Airlines are the top three most popular airlines that fly to London 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. Keep in mind that there are 3 different airlines that fly to London 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 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.

The number of flights available between State of Washington and London is 172 per week as of September 2026. The most frequent departure day is Tue, with 15% of weekly flights leaving on this day.