Cheap flights from Washington to London from £156

The cheapest month to fly to London from State of Washington is in October. Flight prices, which tend to average around £484, are often lower during this time because this is during the off-season. The month of January is another great option to travel to London, with average flight prices from State of Washington averaging around £485.

Our data shows that Tuesday is the least expensive day to fly to London. Tickets to fly out on this day can be as low as £501. 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 £664.

The cheapest time of day to fly to London is in the evening when flights can be purchased for as low as £553. Flights in the afternoon are often more expensive, with an average ticket price of £622.

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 £587 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 £535 on momondo.

There are 3 cabin classes available to choose from on Washington to London flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

The number of flights available between State of Washington and London is 18 per day as of March 2026. The most frequent departure time is 18:00, with 56% of daily flights leaving in the afternoon.

The number of flights available between State of Washington and London is 130 per week as of March 2026. The most frequent departure day is Fri, with 19% of weekly flights leaving on this day.