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Cheap flights from Seattle to London Heathrow Airport from C$ 618

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 17/5. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
26 May — 2 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 65 days in advance, depart on a Wednesday or Saturday 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 26 April 2026.

Fri 25/93:55 p.m.
SEA
-
LHR
1 stop13h 40m
Scandinavian Airlines
Tue 29/96:40 a.m.
LHR
-
SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 23/4C$ 1,050
Mon 21/911:56 p.m.
SEA
-
LHR
1 stop23h 59m
United Airlines
Thu 24/96:50 a.m.
LHR
-
SEA
2 stops19h 31m
United Airlines
Deal found 24/4C$ 1,076
Tue 6/107:00 a.m.
SEA
-
LHR
2 stops22h 00m
SWISS
Thu 8/106:00 a.m.
LHR
-
SEA
2 stops20h 32m
SWISS
Deal found 22/4C$ 1,082
Sun 20/92:10 p.m.
SEA
-
LHR
1 stop16h 30m
United Airlines
Tue 22/97:25 a.m.
LHR
-
SEA
1 stop17h 34m
United Airlines
Deal found 26/4C$ 1,085
Sun 13/92:10 p.m.
SEA
-
LHR
1 stop14h 30m
Lufthansa
Tue 15/97:25 a.m.
LHR
-
SEA
1 stop17h 34m
Lufthansa
Deal found 22/4C$ 1,086
Fri 28/83:55 p.m.
SEA
-
LHR
2 stops33h 40m
Scandinavian Airlines
Fri 4/96:40 a.m.
LHR
-
SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 22/4C$ 1,091
Fri 28/83:55 p.m.
SEA
-
LHR
2 stops33h 40m
Scandinavian Airlines
Fri 11/97:05 a.m.
LHR
-
SEA
2 stops14h 40m
Scandinavian Airlines
Deal found 26/4C$ 1,096
Sun 27/93:55 p.m.
SEA
-
LHR
2 stops20h 00m
Scandinavian Airlines
Tue 6/107:05 a.m.
LHR
-
SEA
2 stops14h 40m
Scandinavian Airlines
Deal found 25/4C$ 1,100
Sun 6/93:55 p.m.
SEA
-
LHR
1 stop17h 45m
Scandinavian Airlines
Thu 1/107:30 p.m.
LHR
-
SEA
1 stop26h 15m
Scandinavian Airlines
Deal found 22/4C$ 1,101
Sat 26/93:55 p.m.
SEA
-
LHR
2 stops20h 00m
Scandinavian Airlines
Sun 4/106:40 a.m.
LHR
-
SEA
2 stops15h 05m
Scandinavian Airlines
Deal found 25/4C$ 1,104

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 26 April 2026.

Round-trip from

C$ 1,050

One-way from

C$ 618

Popular in

June

Cheapest in

January

Average price

C$ 1,099

Good round-trip deal

C$ 1,118 or less

Good one-way deal

C$ 683 or less
Scandinavian Airlines
  • Scandinavian Airlines
  • 25/9-29/9
  • 2 total stops
  • 28h 45m total
  • Seattle to London
Search Deals
Icelandair
  • Icelandair
  • 17/5
  • 1 total stop
  • 32h 55m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 20% potential increase in price (C$ 386 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (C$ 60 potential savings vs. average RT 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

 
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 26 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 round-trip

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 9/7

11:25 p.m.-8:20 p.m.

1 stop12h 55m

London Heathrow

Sun 30/8

9:25 p.m.-11:45 a.m.

1 stop22h 20m

C$ 1,259

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 10/7

7:00 p.m.-11:55 a.m.

1 stop32h 55m

London Heathrow

Mon 31/8

9:25 p.m.-11:45 a.m.

1 stop22h 20m

C$ 1,261

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 10/7

3:55 p.m.-1:35 p.m.

1 stop13h 40m

London Heathrow

Mon 31/8

7:50 p.m.-1:45 p.m.

2 stops25h 55m

C$ 1,322

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 20/5

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

Nonstop9h 50m

London Heathrow

Wed 27/5

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

Nonstop10h 20m

C$ 1,453

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 29/4

9:45 p.m.-3:35 p.m.

Nonstop9h 50m

London Heathrow

Wed 6/5

6:30 a.m.-4:30 p.m.

1 stop18h 00m

C$ 1,458

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 9/5

7:10 p.m.-10:25 p.m.

1 stop19h 15m

London Heathrow

Fri 29/5

6:30 a.m.-5:15 p.m.

1 stop18h 45m

C$ 1,501

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 10/7

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

Nonstop9h 50m

London Heathrow

Sun 30/8

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

Nonstop10h 20m

C$ 1,513

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 9/7

8:10 p.m.-2:00 p.m.

Nonstop9h 50m

London Heathrow

Mon 31/8

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

Nonstop10h 20m

C$ 1,513

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 14/7

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

Nonstop9h 50m

London Heathrow

Mon 20/7

5:35 p.m.-11:15 a.m.

1 stop25h 40m

C$ 1,599

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 7/7

3:55 p.m.-6:30 p.m.

1 stop18h 35m

London Heathrow

Sun 12/7

7:50 p.m.-11:06 p.m.

2 stops35h 16m

C$ 1,606

Flights are sorted by cheapest round-trip flights first.

Deals found on 26/4

Showing 1-10 of 24 resultsSorted by cheapest first
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2
3

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 64 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$ 877). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,585). 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 26 April 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 26 April 2026.
Read through reviews of airlines operating flights from Seattle to London Heathrow Airport, such as Virgin Atlantic,Icelandair, andBritish 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

Crew

8.1

Food

6.9

Entertainment

7.5

Boarding

7.7

Overall

7.4

Comfort

7.3

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

Crew

8.1

Food

6.9

Entertainment

7.5

Boarding

7.7

Overall

7.4

Comfort

7.3

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
642 reviews
Virgin Atlantic
7.4
Good
688 reviews
Check prices

Crew

8.1

Food

6.9

Entertainment

7.5

Boarding

7.7

Overall

7.4

Comfort

7.3

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
7,917 reviews
Virgin Atlantic
7.4
Good
688 reviews
Check prices

Crew

8.1

Food

6.9

Entertainment

7.5

Boarding

7.7

Overall

7.4

Comfort

7.3

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 21 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 3 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 50m. Fly via Icelandair, Scandinavian Airlines, or Delta 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$ 624. Additional round-trip tickets that might be worth considering are offered by Icelandair and British Airways, with the lowest prices starting at C$ 645 and C$ 694, respectively. Users have found that Virgin Atlantic is 43% 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 (95%), Delta (94%), Virgin Atlantic (94%).

  • 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$ 1,944, our data shows the cheapest flight currently is C$ 583. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay C$ 1,125 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$ 877). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,585). 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
Slough
Marlow
Cobham
Leamington Spa
Watford
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 3 airlines flying from Seattle to Heathrow

Discover the top 3 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 26 April 2026.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapestC$ 624AverageC$ 989FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
IcelandairCheapestC$ 645AverageC$ 714FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
British AirwaysCheapestC$ 694AverageC$ 941FlexibilityNo cancel feeOn-time70%
Search British Airways 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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