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Cheap flights from Seattle to London Heathrow Airport from C$ 553

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 26/4. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
9 Apr — 16 Apr1
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 26 days in advance, depart on a Sunday or Wednesday and return on a Monday

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 10 March 2026.

Thu 20/87:00 p.m.
SEA
-
LHR
1 stop32h 55m
Icelandair
Thu 24/91:05 p.m.
LHR
-
SEA
1 stop15h 35m
Icelandair
Deal found 5/3C$ 797
Wed 30/97:00 p.m.
SEA
-
LHR
1 stop32h 55m
Icelandair
Sat 24/109:25 p.m.
LHR
-
SEA
1 stop31h 20m
Icelandair
Deal found 7/3C$ 816
Sat 13/63:55 p.m.
SEA
-
LHR
2 stops21h 25m
Scandinavian Airlines
Mon 15/65:00 p.m.
LHR
-
SEA
1 stop28h 45m
Scandinavian Airlines
Deal found 5/3C$ 853
Tue 1/97:00 p.m.
SEA
-
LHR
1 stop17h 20m
Icelandair
Wed 9/99:25 p.m.
LHR
-
SEA
1 stop31h 15m
Icelandair
Deal found 10/3C$ 857
Wed 19/83:40 p.m.
SEA
-
LHR
1 stop20h 40m
Icelandair
Wed 2/99:25 p.m.
LHR
-
SEA
1 stop22h 20m
Icelandair
Deal found 6/3C$ 864
Mon 13/47:00 p.m.
SEA
-
LHR
1 stop17h 20m
Icelandair
Tue 21/41:05 p.m.
LHR
-
SEA
1 stop15h 35m
Icelandair
Deal found 9/3C$ 866
Mon 13/43:40 p.m.
SEA
-
LHR
1 stop12h 15m
Icelandair
Fri 24/49:25 p.m.
LHR
-
SEA
1 stop31h 15m
Icelandair
Deal found 9/3C$ 868
Fri 28/83:55 p.m.
SEA
-
LHR
2 stops33h 40m
Scandinavian Airlines
Mon 7/97:30 p.m.
LHR
-
SEA
1 stop26h 15m
Scandinavian Airlines
Deal found 6/3C$ 870
Sat 26/93:55 p.m.
SEA
-
LHR
2 stops17h 05m
Scandinavian Airlines
Mon 5/109:05 p.m.
LHR
-
SEA
2 stops24h 40m
Scandinavian Airlines
Deal found 9/3C$ 872

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 10 March 2026.

Round-trip from

C$ 797

One-way from

C$ 553

Popular in

June

Cheapest in

January

Average price

C$ 1,006

Good round-trip deal

C$ 983 or less

Good one-way deal

C$ 457 or less
Icelandair
  • Icelandair
  • 20/8-24/9
  • 2 total stops
  • 48h 30m total
  • Seattle to London
Search Deals
Icelandair
  • Icelandair
  • 26/4
  • 1 total stop
  • 32h 55m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 16% potential increase in price (C$ 272 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (C$ 43 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 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 10 March 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

Mon 4/5

3:40 p.m.-11:55 a.m.

1 stop12h 15m

London Heathrow

Fri 15/5

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

1 stop31h 15m

C$ 889

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

9:55 p.m.-3:35 p.m.

Nonstop9h 40m

London Heathrow

Wed 2/9

9:55 a.m.-4:35 p.m.

1 stop14h 40m

C$ 950

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 20/8

11:10 a.m.-6:30 p.m.

2 stops23h 20m

London Heathrow

Thu 24/9

7:30 p.m.-1:45 p.m.

1 stop26h 15m

C$ 976

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 5/9

11:00 p.m.-9:35 p.m.

1 stop14h 35m

London Heathrow

Tue 15/9

9:30 a.m.-11:17 a.m.

2 stops33h 47m

C$ 982

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

9:55 p.m.-3:35 p.m.

Nonstop9h 40m

London Heathrow

Wed 2/9

11:40 a.m.-2:00 p.m.

Nonstop10h 20m

C$ 991

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

1:32 p.m.-11:15 a.m.

1 stop13h 43m

London Heathrow

Wed 2/9

9:50 a.m.-11:35 a.m.

Nonstop9h 45m

C$ 997

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 20/8

9:55 p.m.-3:35 p.m.

Nonstop9h 40m

London Heathrow

Thu 24/9

6:15 a.m.-11:15 a.m.

1 stop13h 00m

C$ 1,028

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 3/5

7:00 p.m.-8:20 p.m.

1 stop17h 20m

London Heathrow

Sat 9/5

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

1 stop31h 15m

C$ 1,029
Quickest round-trip

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

9:45 p.m.-3:05 p.m.

Nonstop9h 20m

London Heathrow

Wed 2/9

5:00 p.m.-6:55 p.m.

Nonstop9h 55m

C$ 1,031
Cheapest one-way

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 19/4

10:20 a.m.-1:20 p.m.

1 stop19h 00m

C$ 584

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/3

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?

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Heathrow. Price data was last updated on 6 March 2026.

The best time to book flights from Seattle to London Heathrow Airport is 26 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, October is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of C$ 682). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,026). 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 10 March 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?

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 10 March 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
680 reviews
Check prices

Entertainment

7.6

Food

6.9

Comfort

7.3

Overall

7.5

Crew

8.2

Boarding

7.7

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
680 reviews
Virgin Atlantic
7.5
Good
680 reviews
Check prices

Entertainment

7.6

Food

6.9

Comfort

7.3

Overall

7.5

Crew

8.2

Boarding

7.7

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
7,781 reviews
Virgin Atlantic
7.5
Good
680 reviews
Check prices

Entertainment

7.6

Food

6.9

Comfort

7.3

Overall

7.5

Crew

8.2

Boarding

7.7

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 15 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 9h 40m. Fly via Icelandair, Delta, or Scandinavian Airlines 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$ 620. Another option worth looking into is British Airways, starting at C$ 689 round trip. Users have found that Virgin Atlantic is 41% 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: American Airlines (87%), Alaska Airlines (87%), Aer Lingus (87%).

  • 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$ 1,826, our data shows the cheapest flight currently is C$ 342. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay C$ 2,885 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, October is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of C$ 682). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,026). 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
Twickenham
Sutton
Gatwick
Slough
Marlow
Cobham
Leamington Spa
Romford
Watford
Bedford
Luton
High Wycombe
Stratford-upon-Avon
Hounslow
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 10 March 2026.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapestC$ 620AverageC$ 964FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapestC$ 689AverageC$ 935FlexibilityNo cancel feeOn-time70%
Search British Airways flights

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

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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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