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Cheap flights from Seattle to London from $173

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to London departing on 10/13. 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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0 bags

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Scandinavian Airlines Logo
4:20 pm - 9:40 pmSEA-LHR
21h 20m1 stop
Scandinavian Airlines Logo
3:35 pm - 2:00 pmLHR-SEA
30h 25m2 stops
$420Scandinavian Airlines
Find Deal
dom., oct. 5 - sáb., oct. 18
Scandinavian Airlines Logo
4:20 pm - 9:40 pmSEA-LHR
21h 20m1 stop
Scandinavian Airlines Logo
6:40 am - 2:00 pmLHR-SEA
39h 20m2 stops
$422Scandinavian Airlines
Find Deal
dom., oct. 5 - sáb., oct. 11
Scandinavian Airlines Logo
4:20 pm - 9:20 amSEA-LHR
33h 00m1 stop
Scandinavian Airlines Logo
6:40 am - 2:00 pmLHR-SEA
15h 20m1 stop
$423Scandinavian Airlines
Find Deal
vie., oct. 3 - vie., oct. 10
Icelandair Logo
2:35 pm - 10:50 amSEA-LHR
12h 15m1 stop
Icelandair Logo
12:15 pm - 5:00 pmLHR-SEA
12h 45m1 stop
$482Icelandair
Find Deal
dom., nov. 9 - mié., nov. 19
Icelandair Logo
3:45 pm - 8:20 pmSEA-LHR
20h 35m1 stop
Icelandair Logo
12:15 pm - 5:00 pmLHR-SEA
12h 45m1 stop
$485Icelandair
Find Deal
mié., oct. 1 - dom., nov. 16
Virgin Atlantic Logo
8:25 pm - 2:15 pmSEA-LHR
9h 50mnonstop
Virgin Atlantic Logo
5:25 pm - 7:45 pmLHR-SEA
10h 20mnonstop
$495Virgin Atlantic
Find Deal
lun., ago. 4 - mié., ago. 20
Virgin Atlantic Logo
8:25 pm - 2:15 pmSEA-LHR
9h 50mnonstop
Virgin Atlantic Logo
12:45 pm - 8:24 pmLHR-SEA
15h 39m1 stop
$500Virgin Atlantic
Find Deal
lun., ago. 4 - mié., ago. 20
British Airways Logo
1:30 pm - 6:50 amSEA-LHR
9h 20mnonstop
British Airways Logo
4:30 pm - 6:20 pmLHR-SEA
9h 50mnonstop
$508British Airways
Find Deal
mié., ago. 13 - mar., ago. 26
Delta Logo
5:35 pm - 11:20 amSEA-LHR
9h 45mnonstop
Delta Logo
6:15 am - 11:15 amLHR-SEA
13h 00m1 stop
$512Delta
Find Deal
lun., ago. 11 - jue., ago. 21
Delta Logo
5:35 pm - 11:20 amSEA-LHR
9h 45mnonstop
Delta Logo
6:30 am - 11:35 amLHR-SEA
13h 05m1 stop
$513Delta
Find Deal
lun., ago. 11 - mié., ago. 20

Scandinavian Airlines flights from Seattle to London Heathrow Airport

Our best Scandinavian Airlines deals on Seattle to London Heathrow Airport flight tickets
Scandinavian Airlines
Oct 5
SEA4:20 pmSeattle/Tacoma Intl
21h 20m
1 stop
LHR9:40 pmLondon Heathrow
Oct 18
LHR3:35 pmLondon Heathrow
30h 25m
2 stops
SEA2:00 pmSeattle/Tacoma Intl
Scandinavian Airlines
Oct 5
SEA4:20 pmSeattle/Tacoma Intl
21h 20m
1 stop
LHR9:40 pmLondon Heathrow
Oct 11
LHR6:40 amLondon Heathrow
39h 20m
2 stops
SEA2:00 pmSeattle/Tacoma Intl
Scandinavian Airlines
Oct 3
SEA4:20 pmSeattle/Tacoma Intl
33h 00m
1 stop
LHR9:20 amLondon Heathrow
Oct 10
LHR6:40 amLondon Heathrow
15h 20m
1 stop
SEA2:00 pmSeattle/Tacoma Intl

Air Canada flights from Seattle to London Heathrow Airport

Our best Air Canada deals on Seattle to London Heathrow Airport flight tickets
Air Canada
Aug 12
SEA7:20 amSeattle/Tacoma Intl
15h 10m
1 stop
LHR6:30 amLondon Heathrow
Aug 27
LHR6:50 amLondon Heathrow
21h 51m
2 stops
SEA8:41 pmSeattle/Tacoma Intl
Air Canada
Jul 13
SEA7:20 amSeattle/Tacoma Intl
15h 10m
1 stop
LHR6:30 amLondon Heathrow
Sep 15
LHR5:10 pmLondon Heathrow
33h 26m
2 stops
SEA6:36 pmSeattle/Tacoma Intl
Air Canada
Jul 12
SEA2:55 pmSeattle/Tacoma Intl
36h 55m
2 stops
LHR11:50 amLondon Heathrow
Sep 15
LHR5:10 pmLondon Heathrow
33h 26m
2 stops
SEA6:36 pmSeattle/Tacoma Intl

See travel insights to London from

How to get the cheapest flight ticket from Seattle to London Heathrow Airport

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 London Heathrow Airport?

The month of March is, on average, the cheapest month to fly to London Heathrow Airport from Seattle, with most prices found around $684. If you’re not able to fly to London Heathrow Airport in March, then April is your next best option. Flight prices from Seattle to London Heathrow Airport during April average around $696.

What is the cheapest day to depart on your flight to London Heathrow Airport?

Our data shows that Tuesday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $819. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $950.

What is the cheapest time of day to depart on your flight to London Heathrow Airport?

According to our data, the cheapest time of day to fly to London Heathrow Airport is in the evening. momondo users have found flights departing from Seattle to London Heathrow Airport in the evening for as low as $862. 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 $987.

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

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

How far in advance should I book a flight to London Heathrow Airport?

You are more likely to see cheaper flights to London Heathrow Airport from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around $812 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from Seattle for as low as $742 on momondo.

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

There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to London Heathrow flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have Seattle to London Heathrow Airport flight prices changed over time?

As of July 2025, prices for Seattle to London Heathrow Airport flights are approximately 36% cheaper when compared to flights at the same time last year.

When to book flights from Seattle to London Heathrow Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Seattle to London Heathrow Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Seattle to London Heathrow Airport (SEA to LHR) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to London Heathrow Airport

Best Price Found

$173

Fastest flight time

9h 20m

Direct flights

Every day
The best one-way flight to London Heathrow Airport from Seattle in the past 72 hours is $173. The best round-trip flight deal from Seattle to London Heathrow Airport found on momondo in the last 72 hours is $420.
The fastest flight from Seattle to London Heathrow Airport takes 9h 20m
Direct flights go from Seattle to London Heathrow Airport every day.

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

    The straight-line distance from Seattle/Tacoma Intl to London Heathrow is 4774.1 mi. 9h 20m is a normal flight duration for this route.

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

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

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

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to London Heathrow 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 Seattle/Tacoma Intl Airport to London Heathrow Airport.

  • What documentation or ID do you need to fly to London Heathrow Airport?

    The travel and health documents you'll need for your trip to London Heathrow 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 London Heathrow 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 Seattle to London Heathrow Airport?

  • What is the most popular airline from Seattle to London Heathrow Airport?


Best airlines flying from Seattle to London Heathrow Airport

Compare and see reviews for airlines that fly from Seattle to London Heathrow Airport with momondo
Airline
Rating
Free Cancellation
Price
LufthansaPriceFrom $378Free CancellationRating
6.8
7,207 reviews
Search Lufthansa flights
United AirlinesPriceFrom $498Free CancellationRating
7.4
8,861 reviews
Search United Airlines flights
IcelandairPriceFrom $506Free CancellationRating
7.0
514 reviews
Search Icelandair flights
Scandinavian AirlinesPriceFrom $532Free CancellationRating
7.3
1,416 reviews
Search Scandinavian Airlines flights
FinnairPriceFrom $556Free CancellationRating
7.6
1,306 reviews
Search Finnair flights
IberiaPriceFrom $579Free CancellationRating
7.0
2,820 reviews
Search Iberia flights
Aer LingusPriceFrom $583Free CancellationRating
7.1
1,144 reviews
Search Aer Lingus flights
Air FrancePriceFrom $597Free CancellationRating
7.5
1,465 reviews
Search Air France flights
KLMPriceFrom $597Free CancellationRating
7.8
1,367 reviews
Search KLM flights
British AirwaysPriceFrom $605Free CancellationRating
6.6
7,093 reviews
Search British Airways flights
  • Delta Flights From Seattle to London Heathrow Airport

    Delta is one of the most popular airlines flying from Seattle to London Heathrow Airport, operating 14 flights/week on average for this route. A good Delta flight deal for Seattle to London Heathrow Airport starts from $614 round-trip, up to an average price of $863. Our users have rated Delta at 8.0/10.

  • Alaska Airlines Flights From Seattle to London Heathrow Airport

    Another popular option for Seattle to London Heathrow Airport flights is Alaska Airlines (8.0/10, 10,000 ratings). Alaska Airlines flies from Seattle to London Heathrow Airport around 13 times per week, with deals starting from $800 round-trip and rising to an average price of around $999.


Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Gatwick
Hounslow
Croydon
Luton
Slough
Dover
Dartford
Guildford
Stansted
Hayes
Milton Keynes
Salisbury
Swindon
Ilford
Colchester
Stratford-upon-Avon
Chelmsford
Canterbury
Watford
Richmond

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to London?

Finding the right flight to London from Seattle is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to London quick and easy, saving you time and money.

Can I find flights from Seattle to London with flexible booking policies on momondo?

Flights from Seattle to London with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from Seattle to London?

Once you have performed a search for Seattle to London flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from Seattle to London right now. Can momondo alert me if prices change?

Price alerts on flights to London from Seattle are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.


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1 adult
mar. 7/8
mar. 7/15

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