Cheap flights from Seattle to the United Kingdom from £199

The cheapest month to fly to United Kingdom from Seattle is in January. Flight prices, which tend to average around £238, are often lower during this time because this is during the off-season. If you are unable to visit United Kingdom during the month of January, then departing from Seattle during the month August is also very affordable. Most momondo users find prices during this month for around £465.

The cheapest day to depart from Seattle to United Kingdom is on a Thursday. Travellers who choose to depart for United Kingdom on a Thursday will often find tickets for as low as £523. When flying out on a Monday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to United Kingdom for around £652.

The cheapest time of day to fly to United Kingdom is in the evening when flights can be purchased for as low as £543. Try not to purchase tickets in the afternoon because they tend to be around £611. Of course, these prices can vary depending on the time of year and what airport you fly to.

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

You are more likely to see cheaper flights to United Kingdom from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to United Kingdom for around £615 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to United Kingdom from Seattle for as low as £538 on momondo.

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

Icelandair, KLM, and Virgin Atlantic are the most popular carriers operating from Seattle/Tacoma Intl to United Kingdom

Virgin Atlantic, Icelandair and British Airways are the top three most popular airlines that fly to United Kingdom from Seattle according to our data. Virgin Atlantic is the first choice among our users, with 41% of people opting to fly with this airline when travelling to United Kingdom. Keep in mind that there are 4 different airlines that fly to United Kingdom on a routine basis, so you have a few additional options to choose from.

Historically, on average around 14% of flights between Seattle and United Kingdom have experienced a delay on any given week. The average delay length over the past 12 months has been 127 minutes.

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

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

According to our data, Virgin Atlantic have had the fewest delays on this route over the last 12 months, with about 6% of their flights experiencing any sort of delay.

20 flights are operational daily from Seattle to United Kingdom as of May 2026. The most popular departure time for this route is 20:00, with 83% of flights per day taking off in the evening.

As of May 2026, there are 146 flights per week flying from Seattle to United Kingdom. The most common day of the week flights depart is Tue, with 16% of flights taking off on this day.