Cheap flights from London to Seattle from £229
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from London to Seattle departing on 20/9. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Icelandair flights from London to Seattle
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How to get the cheapest flight ticket from London to Seattle
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the cheapest month to fly to Seattle?
The cheapest month to fly to Seattle from London is in January. Flight prices, which tend to average around £463, are often lower during this time because this is during the off-season. The month of March is another great option to travel to Seattle, with average flight prices from London averaging around £481.
What is the cheapest day to depart on your flight to Seattle?
According to our data, Tuesday is the cheapest day to fly to Seattle from London. The lowest ticket price found for a Tuesday departure recently was £587. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. 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 Seattle on Sunday is £711.
What is the cheapest time of day to depart on your flight to Seattle?
According to our data, the cheapest time of day to fly to Seattle is in the evening. momondo users have found flights departing from London to Seattle in the evening for as low as £517. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the morning are often more expensive, with an average ticket price of £632.
What is the cheapest London to Seattle/Tacoma Intl flight route?
Fly from London Heathrow to Seattle/Tacoma Intl for the best London - Seattle/Tacoma Intl flight prices
How far in advance should I book a flight to Seattle?
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 £570 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from London for as low as £512 on momondo.
What cabin class options are available on London to Seattle/Tacoma Intl flights?
There are 4 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.
Can stopping save me money on London to Seattle flights?
No. A direct flight is the cheapest option for a flight between London to Seattle.
How have London to Seattle flight prices changed over time?
As of July 2025, prices for London to Seattle flights are approximately 3% cheaper when compared to flights at the same time last year.
How many flights depart from London to Seattle on average per day?
The number of flights available between London and Seattle is 18 per day as of July 2025. The most frequent departure time is 16:00, with 70% of daily flights leaving in the afternoon.
How many flights depart from London to Seattle on average per week?
The number of flights available between London and Seattle is 132 per week as of July 2025. The most frequent departure day is Mon, with 17% of weekly flights leaving on this day.
When to book flights from London to Seattle
Cheap London to Seattle (LON to SEA) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from London to Seattle
How far is London to Seattle/Tacoma Intl by plane?
A flight from London to Seattle/Tacoma Intl will travel around 4781.3 mi. By plane, this route typically takes 12h 30m.
When did momondo last update prices for flights from London to Seattle/Tacoma Intl Airport?
Prices for flights from London to Seattle/Tacoma Intl Airport are updated daily.
How many operators does momondo search for flights from London to Seattle/Tacoma Intl Airport?
As of July 2025, there are 13 operators available to choose from for flights from London to Seattle/Tacoma Intl Airport.
How old do you have to be to fly from London to Seattle/Tacoma Intl Airport?
The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from London to Seattle/Tacoma Intl Airport.
What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?
The travel and health documents you'll need for your trip to Seattle/Tacoma Intl Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Seattle/Tacoma Intl Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from London to Seattle?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from London to Seattle is Airbus A330-900neo (25.70% of total bookings). The next most popular plane models are Boeing 787-10 Dreamliner (24.14%), Boeing 777-300ER (15.69%), and Boeing 787-9 Dreamliner (9.90%).
What is the most popular airline from London to Seattle?
Based on momondo bookings for this flight route, the most popular airline on flight routes from London to Seattle is Virgin Atlantic (35% of total bookings). The next most popular airlines are British Airways (19%), Icelandair (15%), and KLM (10%).
Best airlines flying from London to Seattle
Compare and see reviews for airlines that fly from London to Seattle with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom £7 | Free Cancellation | Rating 7.1 1,144 reviews | |||
| PriceFrom £320 | Free Cancellation | Rating 7.0 514 reviews | |||
| PriceFrom £379 | Free Cancellation | Rating 7.5 1,473 reviews | |||
| PriceFrom £385 | Free Cancellation | Rating 6.8 7,187 reviews | |||
| PriceFrom £386 | Free Cancellation | Rating 7.4 8,845 reviews | |||
| PriceFrom £397 | Free Cancellation | Rating 7.6 1,304 reviews | |||
| PriceFrom £400 | Free Cancellation | Rating 7.8 1,363 reviews | |||
| PriceFrom £414 | Free Cancellation | Rating 7.1 9,659 reviews | |||
| PriceFrom £418 | Free Cancellation | Rating 6.6 7,093 reviews | |||
| PriceFrom £435 | Free Cancellation | Rating 7.4 654 reviews |
Delta Flights From London to Seattle
Delta flight deals from London to Seattle start from £597 round-trip. Over the 12 Delta flights for this route in a normal week, average airfare is usually £822 round-trip - but some users have found much cheaper deals with momondo.
KLM Flights From London to Seattle
KLM (7.8/10 from 1,367 reviews) operates around 12 flights from London to Seattle in any given week. The average KLM airfare for this route is around £770, with deals from around £545 rare but found on momondo. Referenced prices are for round-trip London to Seattle flight searches in the last 72 hours.
Travelling to a place near Seattle?
Book flights to Seattle if you plan to visit one of these locationsWhy use momondo?
Why should I use momondo to find a flight deal from London to Seattle?
momondo collates all your flight options in one place and lets you filter them to find the perfect flight from London to Seattle. momondo saves you time and could save you money on your trip.
Can I find flights from London to Seattle with flexible booking policies on momondo?
Yes. momondo allows you to filter the results for London to Seattle flights to just show those with flexible booking policies.
How can momondo help me find flights from London to Seattle?
Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Seattle from London.
I’m not ready to book a flight from London to Seattle right now. Can momondo alert me if prices change?
Yes. momondo can track prices for London to Seattle flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.