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Cheap flights from Seattle to London Heathrow Airport from £221

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 14/7. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
29 Jul — 5 Aug1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London Heathrow are usually found in January or February, booked 65 days in advance, depart on a Thursday or Wednesday and return on a Wednesday

Cheap flight deals from Seattle to Heathrow

Enter your travel dates to find the best prices.

Cheapest flights from Seattle to Heathrow
Explore the most affordable flight options available from Seattle to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 29 June 2026.

Tue 20/1019:00
SEA
-
LHR
1 stop32h 55m
Icelandair
Tue 27/1020:35
LHR
-
SEA
1 stop28h 25m
Icelandair
Deal found 28/6£538
Wed 18/1114:35
SEA
-
LHR
1 stop12h 15m
Icelandair
Sun 18/421:25
LHR
-
SEA
1 stop28h 30m
Icelandair
Deal found 27/6£539
Tue 25/815:40
SEA
-
LHR
1 stop20h 40m
Icelandair
Tue 8/921:25
LHR
-
SEA
1 stop22h 20m
Icelandair
Deal found 26/6£540
Tue 25/815:40
SEA
-
LHR
1 stop20h 40m
Icelandair
Sun 6/921:25
LHR
-
SEA
1 stop22h 20m
Icelandair
Deal found 28/6£541
Wed 30/919:00
SEA
-
LHR
1 stop17h 20m
Icelandair
Fri 30/1012:15
LHR
-
SEA
1 stop12h 45m
Icelandair
Deal found 27/6£542
Sat 26/915:40
SEA
-
LHR
1 stop12h 15m
Icelandair
Sat 3/1021:25
LHR
-
SEA
1 stop28h 30m
Icelandair
Deal found 28/6£542
Wed 9/919:00
SEA
-
LHR
1 stop17h 20m
Icelandair
Wed 23/921:25
LHR
-
SEA
1 stop31h 15m
Icelandair
Deal found 26/6£543
Tue 18/823:25
SEA
-
LHR
1 stop28h 30m
Icelandair
Wed 30/921:25
LHR
-
SEA
1 stop28h 30m
Icelandair
Deal found 27/6£544
Thu 20/819:00
SEA
-
LHR
2 stops18h 40m
Multiple Airlines
Wed 26/810:20
LHR
-
SEA
2 stops18h 20m
Multiple Airlines
Deal found 27/6£545
Sat 22/823:25
SEA
-
LHR
1 stop28h 30m
Icelandair
Mon 31/821:25
LHR
-
SEA
1 stop22h 20m
Icelandair
Deal found 27/6£546
Sun 13/915:40
SEA
-
LHR
1 stop12h 15m
Icelandair
Sun 4/1013:05
LHR
-
SEA
1 stop12h 50m
Icelandair
Deal found 28/6£547
Sun 6/915:40
SEA
-
LHR
1 stop20h 40m
Icelandair
Mon 21/921:25
LHR
-
SEA
1 stop28h 30m
Icelandair
Deal found 28/6£548

Find flight deals from Seattle to Heathrow

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Heathrow (LHR). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 29 June 2026.

Round-trip from

£538

One-way from

£221

Popular in

June

Cheapest in

January

Average price

£935

Good round-trip deal

£775 or less

Good one-way deal

£328 or less
Icelandair
  • Icelandair
  • 20/10-27/10
  • 2 total stops
  • 61h 20m total
  • Seattle to London
Search Deals
14/7
  • 14/7
  • 2 total stops
  • 33h 25m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 22% potential increase in price (£135 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (£22 potential savings vs. average return price).
Search Deals
Average for round-trip flights in June 2026
Search Deals
Price to beat on a round-trip flight from Seattle/Tacoma Intl to London Heathrow.
Search Deals
Price to beat on a one-way flight from Seattle/Tacoma Intl to London Heathrow.
Search Deals

Cheapflights Fare Finder

 
Customise your flight search to find flights from Seattle to Heathrow 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, Cheapflights users made 858,174 searches. Data last updated 29 June 2026.
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

Cheapest return flight

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 20/11

14:35-10:50

1 stop12h 15m

London Heathrow

Mon 19/4

21:25-17:55

1 stop28h 30m

£560

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 27/8

09:10-16:00

2 stops22h 50m

London Heathrow

Sat 5/9

15:35-13:45

2 stops30h 10m

£652

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 28/8

07:00-11:35

1 stop20h 35m

London Heathrow

Sun 30/8

11:05-18:41

2 stops39h 36m

£697

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 11/8

21:45-15:35

Nonstop9h 50m

London Heathrow

Tue 18/8

06:30-11:37

1 stop13h 07m

£698

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 13/8

21:45-15:35

Nonstop9h 50m

London Heathrow

Wed 19/8

09:55-16:27

1 stop14h 32m

£717

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 28/7

18:20-12:10

Nonstop9h 50m

London Heathrow

Wed 12/8

17:45-20:03

Nonstop10h 18m

£720

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 5/8

21:45-15:35

Nonstop9h 50m

London Heathrow

Wed 12/8

17:45-20:03

Nonstop10h 18m

£720

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 26/7

18:20-12:10

Nonstop9h 50m

London Heathrow

Wed 12/8

17:45-20:03

Nonstop10h 18m

£720

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 30/7

21:50-15:35

Nonstop9h 45m

London Heathrow

Wed 5/8

17:45-20:03

Nonstop10h 18m

£792

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 3/8

23:25-20:20

1 stop12h 55m

London Heathrow

Wed 19/8

13:05-20:35

2 stops15h 30m

£885

Flights are sorted by cheapest return flights first.

Deals found on 24/6

Showing 1-10 of 24 resultsSorted by cheapest first
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2
3

Best time to book a flight from Seattle to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Seattle with our price prediction graph.
Estimated return price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Seattle to London Heathrow Airport

How far ahead should I book a flight from Seattle to London Heathrow Airport?

The price you pay for your flight from Seattle to London Heathrow Airport may vary depending on when you book. For the best chance of a lower fare, look to book 64 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Seattle to London Heathrow Airport?

Currently, January is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £486). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £935). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to LHR?

Find hourly flight availability from Seattle to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 29 June 2026.

When flying from Seattle to London Heathrow Airport, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

How much does it cost for a return flight from Seattle to London Heathrow Airport?

Reviews of airlines servicing Heathrow

Get insights into the airlines that provide service to Heathrow. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Heathrow. Reviews last updated 29 June 2026.
Read through reviews of airlines operating flights from Seattle to London Heathrow Airport, such as Virgin Atlantic and British Airways. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Virgin Atlantic
7.5
Good
690 reviews
Check prices

Comfort

7.3

Crew

8.1

Overall

7.5

Boarding

7.7

Entertainment

7.5

Food

6.9

Reviews

1 / 20
6.0
Good

Pratap,Aug 2025

JFK - LHR

The flight is clean, food good and the staff are excellent! Very professional, polite and accommodating. The seat itself is really mediocre. Can’t believe there is not inch of storage space. Believe it or not it there is not place even to put away your phone or pen!! Very very surprising and terribly inconvenient. No coat hanger hook either. Had to give it away. ALL IN ALL VERY INCONVENIENT business class seat compared to their peers. What is even more surprising is that this on their relatively new fleet of Airbus A350-1000. I was having com platelets different expectations of Virgin and this has disappointed me. Everything else is just as good and as you would expect from Virgin!
Virgin Atlantic
7.5
Good
690 reviews
Virgin Atlantic
7.5
Good
690 reviews
Check prices

Comfort

7.3

Crew

8.1

Overall

7.5

Boarding

7.7

Entertainment

7.5

Food

6.9

Reviews

1 / 20
6.0
Good

Pratap,Aug 2025

JFK - LHR

The flight is clean, food good and the staff are excellent! Very professional, polite and accommodating. The seat itself is really mediocre. Can’t believe there is not inch of storage space. Believe it or not it there is not place even to put away your phone or pen!! Very very surprising and terribly inconvenient. No coat hanger hook either. Had to give it away. ALL IN ALL VERY INCONVENIENT business class seat compared to their peers. What is even more surprising is that this on their relatively new fleet of Airbus A350-1000. I was having com platelets different expectations of Virgin and this has disappointed me. Everything else is just as good and as you would expect from Virgin!
British Airways
6.7
Okay
8,082 reviews
Virgin Atlantic
7.5
Good
690 reviews
Check prices

Comfort

7.3

Crew

8.1

Overall

7.5

Boarding

7.7

Entertainment

7.5

Food

6.9

Reviews

1 / 20
6.0
Good

Pratap,Aug 2025

JFK - LHR

The flight is clean, food good and the staff are excellent! Very professional, polite and accommodating. The seat itself is really mediocre. Can’t believe there is not inch of storage space. Believe it or not it there is not place even to put away your phone or pen!! Very very surprising and terribly inconvenient. No coat hanger hook either. Had to give it away. ALL IN ALL VERY INCONVENIENT business class seat compared to their peers. What is even more surprising is that this on their relatively new fleet of Airbus A350-1000. I was having com platelets different expectations of Virgin and this has disappointed me. Everything else is just as good and as you would expect from Virgin!

Related info for your journey

Find useful and relevant information for your journey from Seattle to Heathrow. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Seattle to London Heathrow?

    If you book a flight to London Heathrow from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 20 flights from Seattle/Tacoma Intl to London Heathrow per day from 2 different airlines.

  • How long is the flight from Seattle to London Heathrow Airport?

    For as low as £560, Icelandair can have you in London Heathrow Airport from Seattle in 12h 15m. The distance from Seattle to London Heathrow Airport is about 4783 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines flying from Seattle to London Heathrow Airport round-trip?

    Cheapflights users have booked flights from Seattle to London Heathrow Airport round-trip from £359. Another airline that can offer you cheap pricing is Virgin Atlantic. You may be able to fly from Seattle to London Heathrow Airport for 43% less than the average price by searching for these airlines.

  • What are the cheapest airlines to fly from Seattle to London Heathrow Airport one-way?

    One-way options have recently been found by users for as low as £204 on Icelandair. Other airlines that offer cheap prices include Virgin Atlantic from £278 and British Airways from £311 one-way.

  • What are the most reliable airlines from Seattle to London Heathrow Airport?

    Consider KLM (89%), Air France (89%) or Delta (89%) when booking your flight. These represent the most reliable airlines when flying from Seattle to London Heathrow Airport.

  • What are the cheapest flights from Seattle to London Heathrow Airport?

    While on average a flight from Seattle to London Heathrow Airport is generally £704, our data shows the cheapest flight currently is £278. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £194 for that flight.

  • Can I find deals for flights from Seattle to Heathrow that include hotel bookings?

    Yes. In addition to deals on Seattle to Heathrow flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Heathrow?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Heathrow.

  • Can I find deals for business class flights from Seattle to Heathrow?

    Yes. Cheapflights offers flight deals from Seattle to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Seattle to London Heathrow Airport?

    Currently, January is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £486). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £935). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Travelling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Hounslow
Milton Keynes
Luton
Wembley
Gatwick
Croydon
Slough
Ilford
Hayes
Brentford
Colchester
Northampton
Watford
Kingston upon Thames
Swindon
Eastbourne
Poole
Southall
Aylesbury
Romford

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top 2 airlines flying from Seattle to Heathrow

Discover the top 2 airlines that operate flights from Seattle to Heathrow. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 858,174 searches. Data last updated 29 June 2026.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest£359Average£626FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£373Average£597FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Seattle to Heathrow?

Cheapflights helps you search for flights from Seattle to Heathrow via 900+ travel sites so you don’t have to. After performing a flight search, users can also filter their flight selection by filtering for price, number of stops, airlines, and so on.

Why should you use Cheapflights to find cheap flight tickets from Seattle to Heathrow?

Cheapflights helps you find that perfect flight to Heathrow from Seattle by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Seattle to Heathrow with no change fees?

Yes! Cheapflights helps users easily find flights from Seattle to Heathrow with no change fees.

Can Cheapflights notify me if prices for flights from Seattle to Heathrow become cheaper?

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

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