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Cheap flights from Seattle to London Heathrow Airport from C$ 414

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 20/9. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
23 Aug — 30 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 35 days in advance, depart on a Saturday or Wednesday and return on a Tuesday

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 24 July 2026.

Fri 18/97:15 a.m.
SEA
-
LHR
2 stops22h 20m
Scandinavian Airlines
Sun 20/96:40 a.m.
LHR
-
SEA
2 stops15h 05m
Scandinavian Airlines
Deal found 23/7C$ 942
Sat 17/107:00 p.m.
SEA
-
LHR
1 stop32h 55m
Icelandair
Tue 27/108:35 p.m.
LHR
-
SEA
1 stop28h 25m
Icelandair
Deal found 21/7C$ 959
Sun 13/93:55 p.m.
SEA
-
LHR
1 stop18h 35m
Scandinavian Airlines
Sat 19/96:40 a.m.
LHR
-
SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 23/7C$ 966
Thu 1/107:00 p.m.
SEA
-
LHR
1 stop17h 20m
Icelandair
Sun 11/109:25 p.m.
LHR
-
SEA
1 stop28h 30m
Icelandair
Deal found 23/7C$ 981
Sat 19/93:55 p.m.
SEA
-
LHR
2 stops18h 55m
Scandinavian Airlines
Sat 26/96:40 a.m.
LHR
-
SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 19/7C$ 988
Sat 26/93:55 p.m.
SEA
-
LHR
1 stop17h 45m
Scandinavian Airlines
Sun 4/106:40 a.m.
LHR
-
SEA
2 stops15h 05m
Scandinavian Airlines
Deal found 22/7C$ 994
Wed 9/97:00 p.m.
SEA
-
LHR
1 stop17h 20m
Icelandair
Thu 24/91:05 p.m.
LHR
-
SEA
1 stop12h 50m
Icelandair
Deal found 23/7C$ 1,002
Sat 31/103:35 p.m.
SEA
-
LHR
1 stop12h 15m
Icelandair
Wed 3/312:15 p.m.
LHR
-
SEA
1 stop12h 45m
Icelandair
Deal found 21/7C$ 1,008

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 24 July 2026.

Round-trip from

C$ 942

One-way from

C$ 414

Popular in

June

Cheapest in

January

Average price

C$ 1,442

Good round-trip deal

C$ 838 or less

Good one-way deal

C$ 527 or less
Scandinavian Airlines
  • Scandinavian Airlines
  • 18/9-20/9
  • 4 total stops
  • 37h 25m total
  • Seattle to London
Search Deals
Icelandair
  • Icelandair
  • 20/9
  • 1 total stop
  • 12h 15m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 21% potential increase in price (C$ 462 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (C$ 74 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 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

 
Customize 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 629,999 searches. Data last updated 24 July 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 round-trip

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 13/9

3:55 p.m.-7:55 p.m.

2 stops20h 00m

London Heathrow

Sun 27/9

6:40 a.m.-1:45 p.m.

2 stops15h 05m

C$ 1,067

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

7:00 a.m.-11:35 a.m.

2 stops20h 35m

London Heathrow

Wed 2/9

10:50 a.m.-4:59 p.m.

1 stop14h 09m

C$ 1,211
Quickest round-trip

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 1/11

6:55 p.m.-12:20 p.m.

Nonstop9h 25m

London Heathrow

Tue 2/3

2:45 p.m.-4:50 p.m.

Nonstop10h 05m

C$ 1,215

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 19/10

10:47 a.m.-4:00 p.m.

2 stops21h 13m

London Heathrow

Mon 2/11

7:30 p.m.-10:05 p.m.

2 stops34h 35m

C$ 1,218

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 9/11

2:30 p.m.-6:30 p.m.

2 stops20h 00m

London Heathrow

Mon 23/11

6:40 a.m.-10:04 p.m.

2 stops23h 24m

C$ 1,218

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

6:20 p.m.-12:10 p.m.

Nonstop9h 50m

London Heathrow

Wed 2/9

11:45 a.m.-4:35 p.m.

1 stop12h 50m

C$ 1,264

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

6:20 p.m.-12:10 p.m.

Nonstop9h 50m

London Heathrow

Wed 2/9

8:40 a.m.-4:35 p.m.

1 stop15h 55m

C$ 1,270

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

12:36 p.m.-6:30 p.m.

2 stops21h 54m

London Heathrow

Wed 2/9

6:40 a.m.-8:35 p.m.

2 stops21h 55m

C$ 1,274

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 3/9

8:40 a.m.-9:25 p.m.

2 stops28h 45m

London Heathrow

Tue 8/9

6:55 a.m.-4:59 p.m.

1 stop18h 04m

C$ 1,292
Cheapest one-way

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 4/11

8:40 a.m.-11:50 a.m.

1 stop19h 10m

C$ 458

Flights are sorted by cheapest round-trip flights first.

Deals found on 24/7

Showing 1-10 of 20 resultsSorted by cheapest first
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 round-trip 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 best time to book flights from Seattle to London Heathrow Airport is 34 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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 C$ 904). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,755). 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 24 July 2026.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Seattle to London Heathrow Airport as you normally would.

How much does it cost to fly round-trip from Seattle to London Heathrow Airport?

Airfare is below average for this route at the moment.

Seattle to London Heathrow Airport flights typically cost between C$ 1,067 and C$ 1,501 in September.
The cheapest round-trip price found within the last 5 days was C$ 942 on Scandinavian Airlines (18 Sep-20 Sep).

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 24 July 2026.
Read through reviews of airlines operating flights from Seattle to London Heathrow Airport, such as Virgin Atlantic and Icelandair. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Virgin Atlantic
7.5
Good
694 reviews
Check prices

Boarding

7.7

Overall

7.5

Entertainment

7.5

Comfort

7.3

Crew

8.1

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
694 reviews
Virgin Atlantic
7.5
Good
694 reviews
Check prices

Boarding

7.7

Overall

7.5

Entertainment

7.5

Comfort

7.3

Crew

8.1

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!
Icelandair
7.0
Good
717 reviews
Virgin Atlantic
7.5
Good
694 reviews
Check prices

Boarding

7.7

Overall

7.5

Entertainment

7.5

Comfort

7.3

Crew

8.1

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?

    Seattle/Tacoma Intl (SEA) is the airport you will fly out of if you book a flight from Seattle to London Heathrow. You should not have trouble finding flights to London Heathrow from Seattle/Tacoma Intl; the airport handles an average of 23 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 2 airlines have flights from the Seattle airport to London Heathrow. It is only a 18.4 km journey to Seattle/Tacoma Intl (SEA) from Seattle’s city centre.

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

    There are many flights that can get you from Seattle to London Heathrow Airport in 22h 20m. Fly via Scandinavian Airlines or Icelandair to get the fastest option. Airlines will cover a distance of 7697 km. Both multi-stop and direct flights can be found to your destination and back.

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

    Flying on Virgin Atlantic is currently your cheapest option to London Heathrow Airport, with prices starting at C$ 642. Another option worth looking into is Icelandair, starting at C$ 665 round trip. Users have found that Virgin Atlantic is 46% cheaper than the other options available to this destination.

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

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to London Heathrow Airport on time: KLM (82%), Air France (82%), Delta (82%).

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

    While on average a flight from Seattle to London Heathrow Airport is generally C$ 999, our data shows the cheapest flight currently is C$ 340. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay C$ 1,007 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 vacation 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 C$ 904). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,755). 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
Gatwick
Romford
Twickenham
Ilford
Bromley
Sutton
Luton
Slough
Marlow
Cobham
Hounslow
Leamington Spa
Northampton
Watford
High Wycombe
Stratford-upon-Avon
Moreton-in-Marsh

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Seattle to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.
Seattle to Gatwick flights

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 629,999 searches. Data last updated 24 July 2026.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapestC$ 642AverageC$ 1,000FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
IcelandairCheapestC$ 665AverageC$ 922FlexibilityNo cancel feeOn-time76%
Search Icelandair flights

Fly with Cheapflights

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

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

Millions of users choose and trust Cheapflights to book the best flight deals from Seattle to Heathrow for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.

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

Users can book flights with no change fees policies with our dedicated filters. Book flights from Seattle to Heathrow flexibly with Cheapflights today.

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

Yes, Cheapflights offers price alerts on Seattle to Heathrow flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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