Latest deals
Insights
When to book
FAQs
Reviews
Price Alerts

Cheap flights from Seattle to London from £174

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 7/12. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

Discover deals from 900+ travel sites with momondo.

Voted winner of Europe's Best Travel App 2023

Save money when you book flights with momondo

Big names, great deals

Big names, great deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Stopover? Instantly customise your results.

Trusted and free

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

Find the cheapest flights from Seattle to London (SEA-LHR)

Cheap return flights

Virgin Atlantic Logo
20:25 - 14:15SEA-LHR
9h 50mdirect
Virgin Atlantic Logo
11:30 - 17:40LHR-SEA
14h 10m1 stop
£372Virgin Atlantic
Find Deal
So, 7 Sep - Di, 23 Sep
Virgin Atlantic Logo
17:35 - 11:20SEA-LHR
9h 45mdirect
Virgin Atlantic Logo
15:20 - 11:15LHR-SEA
27h 55m1 stop
£373Virgin Atlantic
Find Deal
Mi, 3 Sep - Mi, 10 Sep
Icelandair Logo
23:30 - 11:55SEA-LHR
28h 25m1 stop
Icelandair Logo
21:25 - 20:40LHR-SEA
31h 15m1 stop
£375Icelandair
Find Deal
Di, 9 Sep - Mi, 17 Sep
Delta Logo
11:25 - 10:15SEA-LHR
14h 50m1 stop
Delta Logo
11:30 - 17:40LHR-SEA
14h 10m1 stop
£375Delta
Find Deal
Mi, 3 Sep - Fr, 12 Sep
Delta Logo
17:35 - 11:20SEA-LHR
9h 45mdirect
Delta Logo
06:15 - 17:40LHR-SEA
19h 25m1 stop
£376Delta
Find Deal
So, 14 Sep - Mi, 24 Sep
Icelandair Logo
23:30 - 11:55SEA-LHR
28h 25m1 stop
Icelandair Logo
21:25 - 11:25LHR-SEA
22h 00m1 stop
£378Icelandair
Find Deal
Fr, 5 Sep - Sa, 13 Sep
Iberia Logo
10:11 - 07:20SEA-LHR
13h 09m1 stop
Iberia Logo
09:50 - 11:35LHR-SEA
9h 45mdirect
£385Iberia
Find Deal
Mi, 3 Sep - Fr, 3 Okt
Iberia Logo
13:30 - 06:50SEA-LHR
9h 20mdirect
Iberia Logo
10:05 - 21:48LHR-SEA
18h 43m1 stop
£390Iberia
Find Deal
So, 12 Okt - Mi, 29 Okt
Scandinavian Airlines Logo
16:20 - 16:25SEA-LHR
16h 05m2 stops
Scandinavian Airlines Logo
06:40 - 14:00LHR-SEA
15h 20m1 stop
£392Scandinavian Airlines
Find Deal
Fr, 3 Okt - Fr, 10 Okt
Scandinavian Airlines Logo
16:20 - 17:40SEA-LHR
17h 20m1 stop
Scandinavian Airlines Logo
18:40 - 14:00LHR-SEA
27h 20m1 stop
£397Scandinavian Airlines
Find Deal
So, 5 Okt - Do, 9 Okt

Virgin Atlantic flights from Seattle to London Heathrow Airport

Our best Virgin Atlantic deals on Seattle to London Heathrow Airport flight tickets
Virgin Atlantic
7 Sept
SEA20:25Seattle/Tacoma Intl
9h 50m
LHR14:15London Heathrow
23 Sept
LHR11:30London Heathrow
14h 10m
1 stop
SEA17:40Seattle/Tacoma Intl
£372
Find similar
Virgin Atlantic
3 Sept
SEA17:35Seattle/Tacoma Intl
9h 45m
LHR11:20London Heathrow
10 Sept
LHR15:20London Heathrow
27h 55m
1 stop
SEA11:15Seattle/Tacoma Intl
£373
Find similar
Virgin Atlantic
7 Sept
SEA17:35Seattle/Tacoma Intl
9h 45m
LHR11:20London Heathrow
23 Sept
LHR13:25London Heathrow
10h 05m
SEA15:30Seattle/Tacoma Intl
£374
Find similar

Delta flights from Seattle to London Heathrow Airport

Our best Delta deals on Seattle to London Heathrow Airport flight tickets
Delta
3 Sept
SEA11:25Seattle/Tacoma Intl
14h 50m
1 stop
LHR10:15London Heathrow
12 Sept
LHR11:30London Heathrow
14h 10m
1 stop
SEA17:40Seattle/Tacoma Intl
£375
Find similar
Delta
25 Aug
SEA20:25Seattle/Tacoma Intl
9h 50m
LHR14:15London Heathrow
9 Sept
LHR09:00London Heathrow
16h 40m
1 stop
SEA17:40Seattle/Tacoma Intl
£376
Find similar
Delta
15 Oct
SEA17:35Seattle/Tacoma Intl
9h 45m
LHR11:20London Heathrow
28 Oct
LHR06:20London Heathrow
13h 05m
1 stop
SEA12:25Seattle/Tacoma Intl
£377
Find similar

momondo Fare Finder

 
Customise your flight search to find flights from Seattle to London Heathrow Airport that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 279,928 searches. Data last updated 19 August 2025.
Use the filters below to find and compare flights from Seattle to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

So 7/9

20:25-14:15

Nonstop9h 50m

London Heathrow

Di 23/9

11:30-17:40

1 stop14h 10m

£372

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mi 3/9

17:35-11:20

Nonstop9h 45m

London Heathrow

Mi 10/9

15:20-11:15

1 stop27h 55m

£373

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Di 9/9

23:30-11:55

1 stop28h 25m

London Heathrow

Mi 17/9

21:25-20:40

1 stop31h 15m

£375

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mi 3/9

11:25-10:15

1 stop14h 50m

London Heathrow

Fr 12/9

11:30-17:40

1 stop14h 10m

£375

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

So 14/9

17:35-11:20

Nonstop9h 45m

London Heathrow

Mi 24/9

06:15-17:40

1 stop19h 25m

£376

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fr 5/9

23:30-11:55

1 stop28h 25m

London Heathrow

Sa 13/9

21:25-11:25

1 stop22h 00m

£378

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mi 3/9

10:11-07:20

1 stop13h 09m

London Heathrow

Fr 3/10

09:50-11:35

Nonstop9h 45m

£385

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

So 12/10

13:30-06:50

Nonstop9h 20m

London Heathrow

Mi 29/10

10:05-21:48

1 stop18h 43m

£390

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fr 3/10

16:20-16:25

2 stops16h 05m

London Heathrow

Fr 10/10

06:40-14:00

1 stop15h 20m

£392

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

So 5/10

16:20-17:40

1 stop17h 20m

London Heathrow

Do 9/10

18:40-14:00

1 stop27h 20m

£397

Flights are sorted by cheapest return flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

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?

In general, March is the cheapest month to fly from Seattle to London Heathrow Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around £505. The month of April is another great option to travel to London Heathrow Airport, with average flight prices from Seattle averaging around £516.

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

On average, the least expensive day to fly to London Heathrow Airport from Seattle is on a Tuesday. momondo users have found tickets for Tuesday departures for as low as £508. However, this price may fluctuate depending on the airline, the season, and holidays. Be sure to avoid booking your departure on a Friday as prices are generally higher than usual. According to our data, the average ticket price to London Heathrow Airport on Friday is £724.

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 at midday. momondo users have found flights departing from Seattle to London Heathrow Airport at midday for as low as £591. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. If you have a flexible travel schedule, then try to avoid flying in the evening when prices are £649 on average. Flights to London Heathrow Airport from Seattle in the evening are generally more expensive because this time of day is more convenient for travellers’ schedules.

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 £594 when searching weeks before you fly. 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 £518 on momondo.

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

There are 3 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 August 2025, prices for Seattle to London Heathrow Airport flights are approximately 54% 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 return 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

£174

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 £174. The best return flight deal from Seattle to London Heathrow Airport found on momondo in the last 72 hours is £372.
The fastest flight from Seattle to London Heathrow Airport takes 9h 20m
Direct flights go from Seattle to London Heathrow Airport every day.
Search flight deals

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

    The distance between Seattle/Tacoma Intl and London Heathrow is about 4774.1 mi. By plane, this route typically takes 9h 20m.

  • 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?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify 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
British AirwaysPriceFrom £350Free CancellationRating
6.7
7,283 reviews
Search British Airways flights
IcelandairPriceFrom £358Free CancellationRating
7.0
529 reviews
Search Icelandair flights
Virgin AtlanticPriceFrom £402Free CancellationRating
7.4
657 reviews
Search Virgin Atlantic flights

  • Virgin Atlantic Flights From Seattle to London Heathrow Airport

    Across 14 Virgin Atlantic flights from Seattle to London Heathrow Airport this week, the average price was £843, with the best Virgin Atlantic deals starting from £544 round-trip. 657 users have rated Virgin Atlantic on momondo, with an average score of 7.4/10.

  • British Airways Flights From Seattle to London Heathrow Airport

    Another popular option for Seattle to London Heathrow Airport flights is British Airways (6.7/10, 7,283 ratings). British Airways flies from Seattle to London Heathrow Airport around 12 times per week, with deals starting from £474 round-trip and rising to an average price of around £916.

Travelling to a place near London?

Book flights to London if you plan to visit one of these locations
Eastbourne
Milton Keynes
Luton
Northampton
Maidstone
Slough
Gatwick
Swindon
Canterbury
Stratford-upon-Avon
Southend-on-Sea
Ipswich
Ilford
Guildford
Swanage
Colchester
Worthing
Dartford
Hounslow
Poole

Why use momondo?

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

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to London from Seattle.

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?

momondo helps you find the best flight between Seattle and London by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

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

If you are simply researching potential flights to London, momondo offers a useful price alert feature which will track prices for flights to London from Seattle and alert you when they change.

An easier way to manage your London Heathrow Airport trip

We make it super easy to schedule, organise and travel with friends or family. Trips is free – and available to use no matter where you book.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
So 24/8
So 31/8
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to London