Cheap flights from London to Seattle from C$ 612

If you aren’t able to travel to Seattle during the month of February, then flying in January is also cheap. Prices for this month can be found on momondo for an average of C$ 907.

Our data shows that Monday is the least expensive day to fly to Seattle. Tickets to fly out on this day can be as low as C$ 1,038. If your travel schedule is flexible, try to avoid departing on a Thursday because tickets tend to average around C$ 1,286. These prices are subject to change though, so be sure to set up a Price Alert for flights to Seattle.

Our most recent data shows that the best time of day to fly to Seattle is in the afternoon. Flights from London to Seattle during this time can be as low as C$ 1,031. Flights at noon are often more expensive with an average ticket price of C$ 1,298.

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

You are more likely to see cheaper flights to Seattle from London when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around C$ 1,038 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from London for as low as C$ 975 on momondo.

There are 3 cabin classes available to choose from on London to Seattle/Tacoma Intl 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 7% on your flight if you consider stops on a London to Seattle flight.

As of March 2026, prices for London to Seattle flights are approximately 0% more expensive when compared to flights at the same time last year.

Historically, on average around 11% of flights between London and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 126 minutes.

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

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

According to our data, Delta has had the least delays on this route over the last 12 months, with about 6% of their flights experiencing any sort of delay.

As of March 2026, 12 flights take off from London and land in Seattle each day. The most common flight departure time for this route is 9:00a.m., with 68% of daily flights taking off in the afternoon.

89 flights are operational weekly from London to Seattle as of March 2026. The most popular departure day for this route is Mon, with 17% of flights per week taking off on this day.