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Cheap flights from Seattle to London Heathrow Airport from £312

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 30/4. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
2 May — 9 May1
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 October, booked 65 days in advance, depart on a Tuesday or Thursday 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 2 April 2026.

Tue 18/815:55
SEA
-
LHR
2 stops57h 00m
Scandinavian Airlines
Sat 22/806:40
LHR
-
SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 1/4£490
Tue 21/419:00
SEA
-
LHR
1 stop17h 20m
Icelandair
Wed 29/421:25
LHR
-
SEA
1 stop28h 30m
Icelandair
Deal found 28/3£491
Sat 10/1015:40
SEA
-
LHR
1 stop12h 15m
Icelandair
Tue 20/1021:25
LHR
-
SEA
1 stop31h 15m
Icelandair
Deal found 28/3£493
Tue 8/915:55
SEA
-
LHR
2 stops33h 40m
Scandinavian Airlines
Fri 11/906:40
LHR
-
SEA
2 stops39h 05m
Scandinavian Airlines
Deal found 28/3£494
Fri 18/915:55
SEA
-
LHR
1 stop33h 25m
Scandinavian Airlines
Mon 21/906:40
LHR
-
SEA
2 stops39h 05m
Scandinavian Airlines
Deal found 29/3£494
Thu 16/419:00
SEA
-
LHR
2 stops18h 20m
Multiple Airlines
Thu 23/409:55
LHR
-
SEA
2 stops18h 45m
Multiple Airlines
Deal found 27/3£500
Fri 11/915:55
SEA
-
LHR
2 stops33h 00m
Scandinavian Airlines
Mon 14/906:40
LHR
-
SEA
2 stops23h 25m
Scandinavian Airlines
Deal found 30/3£501
Thu 16/419:00
SEA
-
LHR
2 stops18h 20m
Multiple Airlines
Thu 30/408:45
LHR
-
SEA
3 stops19h 55m
Multiple Airlines
Deal found 28/3£507

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 2 April 2026.

Round-trip from

£490

One-way from

£312

Popular in

June

Cheapest in

January

Average price

£565

Good round-trip deal

£631 or less

Good one-way deal

£402 or less
Scandinavian Airlines
  • Scandinavian Airlines
  • 18/8-22/8
  • 3 total stops
  • 72h 05m total
  • Seattle to London
Search Deals
30/4
  • 30/4
  • 3 total stops
  • 18h 40m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 16% potential increase in price (£84 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£14 potential savings vs. average return price).
Search Deals
Average for round-trip flights in April 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 2 April 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

Wed 29/4

08:42-09:40

2 stops16h 58m

London Heathrow

Tue 5/5

17:50-22:47

2 stops36h 57m

£660

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 8/9

18:20-12:10

Nonstop9h 50m

London Heathrow

Tue 15/9

06:30-11:47

1 stop13h 17m

£676

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 29/4

18:20-12:10

Nonstop9h 50m

London Heathrow

Wed 6/5

11:45-16:30

1 stop12h 45m

£676

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 17/7

23:20-06:55

1 stop23h 35m

London Heathrow

Wed 26/8

10:50-16:59

1 stop14h 09m

£680

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 11/5

05:50-13:20

1 stop23h 30m

London Heathrow

Sun 17/5

11:05-19:00

2 stops39h 55m

£693

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 5/8

08:58-09:20

2 stops16h 22m

London Heathrow

Tue 11/8

16:25-16:59

1 stop32h 34m

£699

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 8/9

13:30-11:00

1 stop13h 30m

London Heathrow

Tue 22/9

11:40-14:00

Nonstop10h 20m

£702

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 2/8

18:20-12:10

Nonstop9h 50m

London Heathrow

Fri 14/8

08:55-17:34

1 stop16h 39m

£732

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 10/9

21:50-15:35

Nonstop9h 45m

London Heathrow

Sun 20/9

11:45-16:35

1 stop12h 50m

£752

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 22/4

21:45-15:35

Nonstop9h 50m

London Heathrow

Mon 4/5

17:35-11:15

1 stop25h 40m

£768

Flights are sorted by cheapest return flights first.

Deals found on 27/3

Showing 1-10 of 22 resultsSorted by cheapest first
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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?

Use this chart to determine the optimal time to book a return flight from Seattle to Heathrow. Price data was last updated on 13 March 2026.

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 65 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, February is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £380). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £569). 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 2 April 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 2 April 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
685 reviews
Check prices

Crew

8.1

Comfort

7.3

Boarding

7.7

Entertainment

7.5

Overall

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
685 reviews
Virgin Atlantic
7.5
Good
685 reviews
Check prices

Crew

8.1

Comfort

7.3

Boarding

7.7

Entertainment

7.5

Overall

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
7,842 reviews
Virgin Atlantic
7.5
Good
685 reviews
Check prices

Crew

8.1

Comfort

7.3

Boarding

7.7

Entertainment

7.5

Overall

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 17 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 £676, United Airlines can have you in London Heathrow Airport from Seattle in 9h 50m. 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 £357. Another airline that can offer you cheap pricing is Virgin Atlantic. You may be able to fly from Seattle to London Heathrow Airport for 39% 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 £162 on Icelandair. Other airlines that offer cheap prices include British Airways from £296 and Virgin Atlantic from £297 one-way.

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

    Consider American Airlines (85%), Alaska Airlines (85%) or Aer Lingus (85%) 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 £858, our data shows the cheapest flight currently is £377. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £530 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, February is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £380). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £569). 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
Milton Keynes
Wembley
Croydon
Northampton
Hounslow
Gatwick
Slough
Ilford
Luton
Hayes
Brentford
Colchester
Guildford
Watford
Kingston upon Thames
Romford
Eastbourne
Swindon
Bedford
Chelmsford

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 2 April 2026.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest£357Average£524FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£372Average£589FlexibilityNo 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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