Find flights
Deals
When to book
Airlines
FAQs

Cheap flights from Seattle to London Heathrow Airport from £279

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 13/12. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
3 Dec — 10 Dec1
1 adult
1 adult, Economy, 0 bags

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London Heathrow are usually found in March or February, booked 89 days in advance, depart on a Tuesday or Thursday and return on a Wednesday

Cheap 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 3 November 2025.

Round-trip from

£394

One-way from

£279

Popular in

June

Cheapest in

March

Average price

£553

Good round-trip deal

£495 or less

Good one-way deal

£467 or less
Icelandair
  • Icelandair
  • 22/2-11/3
  • 2 total stops
  • 25h 00m total
  • Seattle to London
Search Deals
13/12
  • 13/12
  • 3 total stops
  • 40h 00m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 17% potential increase in price (£96 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£16 potential savings vs. average return price).
Search Deals
Average for round-trip flights in November 2025
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

Find 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 3 November 2025.

Tue 11/1114:35SEA - LHR
1 stop12h 15mIcelandair
Thu 20/1112:15LHR - SEA
1 stop12h 45mIcelandair
Deal found 2/11£394
Mon 10/1114:35SEA - LHR
1 stop12h 15mIcelandair
Wed 19/1112:15LHR - SEA
1 stop12h 45mIcelandair
Deal found 2/11£395
Mon 10/1114:35SEA - LHR
1 stop20h 55mIcelandair
Mon 17/1120:35LHR - SEA
1 stop28h 25mIcelandair
Deal found 2/11£396
Mon 10/1114:35SEA - LHR
1 stop12h 15mIcelandair
Thu 20/1112:15LHR - SEA
1 stop12h 45mIcelandair
Deal found 2/11£412
Mon 1/1205:45SEA - LHR
2 stops17h 25mAir Canada
Wed 10/1214:30LHR - SEA
1 stop16h 16mAir Canada
Deal found 1/11£415
Wed 5/1115:55SEA - LHR
1 stop15h 40mAer Lingus
Wed 19/1112:10LHR - SEA
1 stop14h 10mAer Lingus
Deal found 1/11£420
Wed 5/1115:55SEA - LHR
1 stop15h 40mAer Lingus
Wed 12/1108:50LHR - SEA
1 stop17h 30mAer Lingus
Deal found 1/11£420
Sun 9/1120:05SEA - LHR
1 stop15h 45mAer Lingus
Fri 14/1109:50LHR - SEA
1 stop16h 30mAer Lingus
Deal found 2/11£421
Mon 8/1214:35SEA - LHR
1 stop12h 15mIcelandair
Mon 15/1220:35LHR - SEA
1 stop28h 25mIcelandair
Deal found 2/11£423
Tue 9/1214:35SEA - LHR
1 stop20h 55mIcelandair
Mon 15/1220:35LHR - SEA
1 stop28h 25mIcelandair
Deal found 1/11£424
Mon 3/1119:20SEA - LHR
Nonstop9h 30mVirgin Atlantic
Tue 18/1114:45LHR - SEA
Nonstop10h 05mVirgin Atlantic
Deal found 2/11£426
Sat 6/1214:35SEA - LHR
1 stop20h 55mIcelandair
Fri 12/1212:15LHR - SEA
1 stop12h 45mIcelandair
Deal found 1/11£429

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 3 November 2025.
Use the filters below to find and compare flights from Seattle to London Heathrow Airport that are best for you.

Fly from

Seattle

Fly to

Heathrow

Route

Depart

Return

Price

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 4/4

19:00-11:55

1 stop32h 55m

London Heathrow

Sat 11/4

21:25-17:50

1 stop28h 25m

£424

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 10/12

16:48-10:30

Nonstop9h 42m

London Heathrow

Thu 25/12

06:30-11:50

1 stop13h 20m

£438

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 18/2

16:55-10:30

Nonstop9h 35m

London Heathrow

Fri 27/2

06:20-13:20

1 stop15h 00m

£443

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 26/11

07:30-06:50

1 stop15h 20m

London Heathrow

Wed 3/12

12:20-14:58

Nonstop10h 38m

£446

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 5/12

09:25-07:05

1 stop13h 40m

London Heathrow

Fri 12/12

12:20-14:58

Nonstop10h 38m

£465

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 27/2

16:55-10:30

Nonstop9h 35m

London Heathrow

Fri 13/3

06:30-12:35

1 stop13h 05m

£465

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 8/12

07:10-10:40

1 stop19h 30m

London Heathrow

Mon 15/12

12:20-14:58

Nonstop10h 38m

£465

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 2/3

18:50-12:20

Nonstop9h 30m

London Heathrow

Tue 24/3

09:25-12:30

Nonstop10h 05m

£468

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 7/2

16:55-10:30

Nonstop9h 35m

London Heathrow

Sat 14/2

06:20-11:25

1 stop13h 05m

£470

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 2/3

08:00-07:05

1 stop15h 05m

London Heathrow

Tue 24/3

14:45-17:50

Nonstop10h 05m

£471

Flights are sorted by cheapest return flights first.

Deals found on 2/11

Showing 1-10 of 20 results
1
2

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 31 October 2025.

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 89 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, November is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £370). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £602). 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 3 November 2025.

Unlike in the morning, when flights are generally more expensive, you can save up to 42% on flights from Seattle to London Heathrow Airport by exploring options for tickets at midday.

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 3 November 2025.
Read through reviews of airlines operating flights from Seattle to London Heathrow Airport, such as Virgin Atlantic, Aer Lingus, andBritish Airways. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Virgin Atlantic
7.5
Good
671 reviews
Check prices

Crew

8.1

Food

6.9

Comfort

7.3

Boarding

7.7

Entertainment

7.5

Overall

7.5

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
671 reviews
Virgin Atlantic
7.5
Good
671 reviews
Check prices

Crew

8.1

Food

6.9

Comfort

7.3

Boarding

7.7

Entertainment

7.5

Overall

7.5

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!
Aer Lingus
7.2
Good
1,365 reviews
Virgin Atlantic
7.5
Good
671 reviews
Check prices

Crew

8.1

Food

6.9

Comfort

7.3

Boarding

7.7

Entertainment

7.5

Overall

7.5

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
7,494 reviews
Virgin Atlantic
7.5
Good
671 reviews
Check prices

Crew

8.1

Food

6.9

Comfort

7.3

Boarding

7.7

Entertainment

7.5

Overall

7.5

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 9 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 £438, Icelandair can have you in London Heathrow Airport from Seattle in 9h 42m. 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 £360. Another airline that can offer you cheap pricing is Virgin Atlantic. You may be able to fly from Seattle to London Heathrow Airport for 40% 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 £292 on WestJet. Other airlines that offer cheap prices include United Airlines from £300 and Air Canada from £300 one-way.

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

    Consider KLM (89%), Air France (84%) or Delta (84%) 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 £529, our data shows the cheapest flight currently is £398. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £354 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, November is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £370). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £602). 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
Croydon
Slough
Gatwick
Hounslow
Northampton
Luton
Ilford
Wembley
Deal
Hayes
Colchester
Watford
Winchester
Chichester
Swindon
Crawley
Romford
Brentford
Ipswich

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 3 November 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest£360Average£606FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapest£376Average£626FlexibilityNo 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!

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.