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Cheap flights from Seattle to London Heathrow Airport from £335

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 30/5. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
15 Jun — 22 Jun1
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 83 days in advance, depart on a Tuesday or Thursday and return on a Thursday

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 16 May 2026.

Sun 5/715:55
SEA
-
LHR
2 stops17h 05m
Scandinavian Airlines
Tue 21/706:40
LHR
-
SEA
2 stops15h 05m
Scandinavian Airlines
Deal found 13/5£663
Fri 7/823:25
SEA
-
LHR
1 stop28h 30m
Icelandair
Wed 12/821:25
LHR
-
SEA
1 stop22h 20m
Icelandair
Deal found 12/5£663
Sun 9/815:55
SEA
-
LHR
1 stop16h 05m
Scandinavian Airlines
Sat 15/806:40
LHR
-
SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 12/5£664
Sat 5/915:55
SEA
-
LHR
2 stops33h 40m
Scandinavian Airlines
Tue 15/906:40
LHR
-
SEA
2 stops23h 25m
Scandinavian Airlines
Deal found 12/5£665
Sun 24/515:55
SEA
-
LHR
1 stop16h 05m
Scandinavian Airlines
Tue 2/606:40
LHR
-
SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 12/5£666
Tue 26/515:55
SEA
-
LHR
2 stops16h 30m
Scandinavian Airlines
Fri 29/521:05
LHR
-
SEA
2 stops24h 40m
Scandinavian Airlines
Deal found 12/5£666
Wed 19/807:00
SEA
-
LHR
2 stops16h 55m
Multiple Airlines
Wed 2/909:30
LHR
-
SEA
2 stops17h 02m
Multiple Airlines
Deal found 12/5£667
Tue 26/515:55
SEA
-
LHR
2 stops16h 30m
Scandinavian Airlines
Sat 30/510:35
LHR
-
SEA
2 stops35h 10m
Scandinavian Airlines
Deal found 12/5£668
Wed 3/615:40
SEA
-
LHR
1 stop12h 15m
Multiple Airlines
Wed 17/614:10
LHR
-
SEA
1 stop27h 30m
Multiple Airlines
Deal found 12/5£669
Tue 26/515:55
SEA
-
LHR
1 stop16h 05m
Scandinavian Airlines
Mon 8/619:30
LHR
-
SEA
1 stop26h 15m
Scandinavian Airlines
Deal found 12/5£669
Tue 18/815:55
SEA
-
LHR
2 stops16h 30m
Scandinavian Airlines
Fri 28/807:05
LHR
-
SEA
2 stops14h 40m
Scandinavian Airlines
Deal found 12/5£670
Sun 23/815:40
SEA
-
LHR
2 stops21h 55m
Multiple Airlines
Sat 29/818:45
LHR
-
SEA
3 stops46h 55m
Multiple Airlines
Deal found 12/5£671

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 16 May 2026.

Round-trip from

£663

One-way from

£335

Popular in

June

Cheapest in

January

Average price

£732

Good round-trip deal

£695 or less

Good one-way deal

£450 or less
Scandinavian Airlines
  • Scandinavian Airlines
  • 5/7-21/7
  • 4 total stops
  • 32h 10m total
  • Seattle to London
Search Deals
30/5
  • 30/5
  • 3 total stops
  • 18h 35m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 21% potential increase in price (£128 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (£20 potential savings vs. average return price).
Search Deals
Average for round-trip flights in May 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 16 May 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

Tue 13/10

21:50-15:35

Nonstop9h 45m

London Heathrow

Fri 23/10

06:30-11:52

1 stop13h 22m

£678

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 2/6

15:55-16:00

1 stop16h 05m

London Heathrow

Tue 16/6

06:40-13:45

1 stop15h 05m

£691

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 1/9

18:20-12:10

Nonstop9h 50m

London Heathrow

Tue 8/9

17:45-20:13

Nonstop10h 28m

£700

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 12/9

21:50-15:35

Nonstop9h 45m

London Heathrow

Fri 18/9

11:45-16:35

1 stop12h 50m

£715

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 3/9

20:10-14:00

Nonstop9h 50m

London Heathrow

Thu 10/9

08:40-16:35

1 stop15h 55m

£716
Fastest return journey

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 11/10

13:30-06:45

Nonstop9h 15m

London Heathrow

Mon 19/10

09:50-11:35

Nonstop9h 45m

£737

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 12/10

21:50-15:35

Nonstop9h 45m

London Heathrow

Sun 18/10

11:40-14:00

Nonstop10h 20m

£737

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 3/8

21:45-15:05

Nonstop9h 20m

London Heathrow

Tue 11/8

17:00-18:45

Nonstop9h 45m

£751

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 2/8

05:20-07:10

1 stop17h 50m

London Heathrow

Sun 16/8

11:40-14:00

Nonstop10h 20m

£765

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 8/10

20:20-13:45

Nonstop9h 25m

London Heathrow

Sun 18/10

09:50-11:35

Nonstop9h 45m

£774

Flights are sorted by cheapest return flights first.

Deals found on 16/5

Showing 1-10 of 23 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?

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 82 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 £482). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £904). 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 16 May 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 16 May 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
7.4
Good
688 reviews
Check prices

Boarding

7.7

Food

6.9

Entertainment

7.5

Overall

7.4

Comfort

7.3

Crew

8.1

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
7.4
Good
688 reviews
Virgin Atlantic
7.4
Good
688 reviews
Check prices

Boarding

7.7

Food

6.9

Entertainment

7.5

Overall

7.4

Comfort

7.3

Crew

8.1

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
7,981 reviews
Virgin Atlantic
7.4
Good
688 reviews
Check prices

Boarding

7.7

Food

6.9

Entertainment

7.5

Overall

7.4

Comfort

7.3

Crew

8.1

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 21 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 £678, Delta can have you in London Heathrow Airport from Seattle in 9h 45m. 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 £356. Another airline that can offer you cheap pricing is Virgin Atlantic. You may be able to fly from Seattle to London Heathrow Airport for 42% 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 Virgin Atlantic from £299 and British Airways from £300 one-way.

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

    Consider KLM (95%), Delta (95%) or Virgin Atlantic (95%) 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 £955, our data shows the cheapest flight currently is £241. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £477 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 £482). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £904). 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
Hounslow
Croydon
Wembley
Northampton
Luton
Gatwick
Slough
Ilford
Hayes
Brentford
Colchester
Romford
Watford
Kingston upon Thames
Eastbourne
Swindon
Ipswich
Southend-on-Sea
Guildford

Browse thousands of different options on Cheapflights for your next trip

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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 16 May 2026.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest£356Average£523FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£371Average£588FlexibilityNo 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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