Question 1

What is the cheapest London to Seattle/Tacoma Intl flight route?

Accepted Answer

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

Question 2

Which layover airport has the shortest travel time from London to Seattle?

Accepted Answer

Flights connecting via Reykjavik (KEF) have the shortest average one-way travel time: 12h 45m.

Question 3

Which layover airport has the shortest connection time from London to Seattle?

Accepted Answer

Reykjavik (KEF) has the shortest average layover time for this route: 3h 05m.

Question 4

How many flights depart from London to Seattle on average per day?

Accepted Answer

The number of flights available between London and Seattle is 11 per day as of December 2025. The most frequent departure time is 2:00PM, with 80% of daily flights leaving in the afternoon.

Question 5

How many flights depart from London to Seattle on average per week?

Accepted Answer

As of December 2025, 79 flights take off from London and land in Seattle each week. The most common flight departure day for this route is Thu, with 19% of weekly flights taking off on this day.

Question 6

How far in advance should I book a flight to Seattle?

Accepted Answer

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 $762 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 $699 on momondo.

Question 7

What cabin class options are available on London to Seattle/Tacoma Intl flights?

Accepted Answer

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.

Question 8

Which layover airport offers the lowest fares from London to Seattle?

Accepted Answer

Flights via Reykjavik (KEF) offer the lowest average round-trip price of $510.

Question 9

What is the cheapest time of day to depart on your flight to Seattle?

Accepted Answer

Flying to Seattle from London in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $819 when looking at flights departing in the afternoon. Flights to Seattle are more costly in the evening, with an average ticket price of $859. Departure times in the evening fall within the peak daily travel times, which is why tickets can be more expensive.

Question 10

Can stopping save me money on London to Seattle flights?

Accepted Answer

You could potentially save up to 7% on your flight if you consider stops on a London to Seattle flight.

Question 11

Which airline has the best punctuality record on London to Seattle flights?

Accepted Answer

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

Question 12

What is the cheapest month to fly to Seattle?

Accepted Answer

In general, January is the cheapest month to fly from London to Seattle. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $650. If you don’t want to visit Seattle in January, then you should wait until February to fly from London, when ticket prices are also cheap, with an average price of $656.

Question 13

Which airport is the most popular layover for flights between London and Seattle?

Accepted Answer

Reykjavik (KEF) was the most common stop: 93% of momondo users choosing 1-stop flights on this route connected there.

Question 14

How have London to Seattle flight prices changed over time?

Accepted Answer

As of December 2025, prices for London to Seattle flights are approximately 14% more expensive when compared to flights at the same time last year.

Question 15

How often are flights from London to Seattle delayed?

Accepted Answer

Historically, on average around 13% 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 119 minutes.

Question 16

What day of the week experiences the fewest flight delays on this route?

Accepted Answer

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

Question 17

What is the cheapest day to depart on your flight to Seattle?

Accepted Answer

On average, the least expensive day to fly to Seattle from London is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as $777. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Friday is the most expensive day to depart from London because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $942.

Question 18

What is the cheapest airline that flies from London to Seattle/Tacoma Intl?

Accepted Answer

United Airlines, SWISS, and Virgin Atlantic are the most popular carriers operating from London to Seattle/Tacoma Intl

Question 19

What airlines fly to Seattle?

Accepted Answer

British Airways, Delta and Virgin Atlantic are the top three most popular airlines that fly to Seattle from London according to our data. British Airways is the first choice among our users, with 42% of people opting to fly with this airline when traveling to Seattle. Keep in mind that there are 5 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.

Question 20

What is the most punctual flight time for London to Seattle flights?

Accepted Answer

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

Question 21

When did momondo last update prices for flights from London to Seattle/Tacoma Intl Airport?

Accepted Answer

Prices for flights from London to Seattle/Tacoma Intl Airport are refreshed on a daily basis.

Question 22

How many operators does momondo search for flights from London to Seattle/Tacoma Intl Airport?

Accepted Answer

There are 5 operators available for flights from London to Seattle/Tacoma Intl Airport as of December 2025.

Question 23

How old do you have to be to fly from London to Seattle/Tacoma Intl Airport?

Accepted Answer

The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from London to Seattle/Tacoma Intl Airport.

Question 24

What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

Accepted Answer

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.

Best Price Found	$713
Fastest flight time	9h 45m
Direct flights	Every day
Airports in Seattle	1 airport

Airline	Rating	Free Cancellation	Price
Icelandair	PriceFrom $418	Free Cancellation	Rating 7.0 589 reviews	Search Icelandair flights
British Airways	PriceFrom $553	Free Cancellation	Rating 6.7 7,571 reviews	Search British Airways flights
Virgin Atlantic	PriceFrom $574	Free Cancellation	Rating 7.5 675 reviews	Search Virgin Atlantic flights
Delta	PriceFrom $575	Free Cancellation	Rating 7.9 8,007 reviews	Search Delta flights
American Airlines	PriceFrom $589	Free Cancellation	Rating 7.2 11,049 reviews	Search American Airlines flights

Cheap flights from London to Seattle from $530

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 6/3. 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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How to get the cheapest flight ticket from London to Seattle

What is the cheapest month to fly to Seattle?

What is the cheapest day to depart on your flight to Seattle?

What is the cheapest time of day to depart on your flight to Seattle?

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?

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?

You could potentially save up to 7% on your flight if you consider stops on a London to Seattle flight.

How have London to Seattle flight prices changed over time?

As of December 2025, prices for London to Seattle flights are approximately 14% more expensive when compared to flights at the same time last year.

What is the cheapest airline that flies from London to Seattle/Tacoma Intl?

United Airlines, SWISS, and Virgin Atlantic are the most popular carriers operating from London to Seattle/Tacoma Intl

What airlines fly to Seattle?

How often are flights from London to Seattle delayed?

Historically, on average around 13% 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 119 minutes.

What is the most punctual flight time for London to Seattle flights?

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

What day of the week experiences the fewest flight delays on this route?

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

Which airline has the best punctuality record on London to Seattle flights?

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

Which airport is the most popular layover for flights between London and Seattle?

Reykjavik (KEF) was the most common stop: 93% of momondo users choosing 1-stop flights on this route connected there.

Which layover airport offers the lowest fares from London to Seattle?

Flights via Reykjavik (KEF) offer the lowest average round-trip price of $510.

Which layover airport has the shortest travel time from London to Seattle?

Flights connecting via Reykjavik (KEF) have the shortest average one-way travel time: 12h 45m.

Which layover airport has the shortest connection time from London to Seattle?

Reykjavik (KEF) has the shortest average layover time for this route: 3h 05m.

How many flights depart from London to Seattle on average per day?

The number of flights available between London and Seattle is 11 per day as of December 2025. The most frequent departure time is 2:00PM, with 80% of daily flights leaving in the afternoon.

How many flights depart from London to Seattle on average per week?

As of December 2025, 79 flights take off from London and land in Seattle each week. The most common flight departure day for this route is Thu, with 19% of weekly flights taking off on this day.

When to book flights from London to Seattle

Cheap London to Seattle (LON to SEA) flight deals and tips

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How far is London to Seattle/Tacoma Intl by plane?

When did momondo last update prices for flights from London to Seattle/Tacoma Intl Airport?

How many operators does momondo search 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?

What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

What is the most popular plane model from London to Seattle?

What is the most popular airline from London to Seattle?

Best airlines flying from London to Seattle

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