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Cheap flights from Seattle to London Heathrow Airport from C$ 506

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 24/7. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
11 Jul — 18 Jul1
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 Saturday 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 11 June 2026.

Tue 17/114:48 p.m.
SEA
-
LHR
Nonstop9h 42m
Delta
Wed 2/125:35 p.m.
LHR
-
SEA
1 stop25h 50m
Delta
Deal found 10/6C$ 1,214
Sun 6/99:50 p.m.
SEA
-
LHR
Nonstop9h 45m
Delta
Mon 14/95:35 p.m.
LHR
-
SEA
1 stop25h 40m
Delta
Deal found 8/6C$ 1,215
Sun 23/87:00 a.m.
SEA
-
LHR
2 stops16h 55m
SWISS
Tue 25/86:00 a.m.
LHR
-
SEA
2 stops20h 32m
SWISS
Deal found 10/6C$ 1,217
Tue 13/106:20 p.m.
SEA
-
LHR
Nonstop9h 50m
KLM
Tue 20/105:45 p.m.
LHR
-
SEA
Nonstop10h 29m
KLM
Deal found 8/6C$ 1,218
Sun 20/99:45 p.m.
SEA
-
LHR
Nonstop9h 20m
Multiple Airlines
Sun 27/99:50 a.m.
LHR
-
SEA
Nonstop9h 45m
Multiple Airlines
Deal found 8/6C$ 1,220
Tue 4/83:55 p.m.
SEA
-
LHR
2 stops17h 05m
Scandinavian Airlines
Fri 14/86:40 a.m.
LHR
-
SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 9/6C$ 1,221
Wed 14/103:29 p.m.
SEA
-
LHR
2 stops18h 21m
SWISS
Wed 28/109:00 a.m.
LHR
-
SEA
2 stops21h 21m
SWISS
Deal found 8/6C$ 1,222
Wed 16/91:30 p.m.
SEA
-
LHR
Nonstop9h 15m
British Airways
Thu 1/109:50 a.m.
LHR
-
SEA
Nonstop9h 45m
British Airways
Deal found 8/6C$ 1,224
Fri 28/811:25 p.m.
SEA
-
LHR
1 stop28h 30m
Icelandair
Sat 12/99:25 p.m.
LHR
-
SEA
1 stop22h 20m
Icelandair
Deal found 8/6C$ 1,225
Mon 14/99:50 p.m.
SEA
-
LHR
Nonstop9h 45m
KLM
Tue 22/95:45 p.m.
LHR
-
SEA
Nonstop10h 25m
KLM
Deal found 9/6C$ 1,226
Mon 14/99:45 p.m.
SEA
-
LHR
Nonstop9h 20m
Alaska Airlines
Thu 1/105:00 p.m.
LHR
-
SEA
Nonstop9h 55m
Alaska Airlines
Deal found 8/6C$ 1,228
Sat 19/97:20 p.m.
SEA
-
LHR
2 stops27h 10m
Air Canada
Wed 30/910:15 a.m.
LHR
-
SEA
2 stops16h 17m
Air Canada
Deal found 8/6C$ 1,229

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 11 June 2026.

Round-trip from

C$ 1,214

One-way from

C$ 506

Popular in

June

Cheapest in

January

Average price

C$ 1,720

Good round-trip deal

C$ 1,338 or less

Good one-way deal

C$ 904 or less
Delta
  • Delta
  • 17/11-2/12
  • 1 total stop
  • 35h 32m total
  • Seattle to London
Search Deals
24/7
  • 24/7
  • 2 total stops
  • 32h 49m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 22% potential increase in price (C$ 469 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (C$ 73 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 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 11 June 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 14/9

9:50 p.m.-3:35 p.m.

Nonstop9h 45m

London Heathrow

Tue 22/9

5:45 p.m.-8:10 p.m.

Nonstop10h 25m

C$ 1,226

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$ 1,254

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

7:11 a.m.-10:00 a.m.

2 stops18h 49m

London Heathrow

Wed 2/9

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

1 stop14h 09m

C$ 1,259
Quickest round-trip

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 18/9

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

Nonstop9h 20m

London Heathrow

Thu 1/10

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

Nonstop9h 55m

C$ 1,268

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 22/9

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

Nonstop9h 20m

London Heathrow

Sat 3/10

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

Nonstop9h 55m

C$ 1,268

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/8

2:50 p.m.-6:30 p.m.

2 stops19h 40m

London Heathrow

Wed 2/9

7:30 p.m.-7:52 p.m.

2 stops32h 22m

C$ 1,291

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 7/8

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

2 stops18h 35m

London Heathrow

Mon 17/8

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

2 stops25h 55m

C$ 1,298

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 17/9

9:50 p.m.-3:35 p.m.

Nonstop9h 45m

London Heathrow

Fri 2/10

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

Nonstop10h 20m

C$ 1,298

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 20/11

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

Nonstop9h 25m

London Heathrow

Fri 27/11

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

Nonstop10h 05m

C$ 1,331

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 23/7

9:50 p.m.-3:35 p.m.

Nonstop9h 45m

London Heathrow

Thu 13/8

11:45 a.m.-4:27 p.m.

1 stop12h 42m

C$ 1,360

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/6

Showing 1-10 of 22 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 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$ 895). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,720). 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 11 June 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 11 June 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
7.5
Good
689 reviews
Check prices

Overall

7.5

Food

6.9

Boarding

7.7

Comfort

7.3

Entertainment

7.5

Crew

8.1

Reviews

1 / 20
10.0
Excellent

Edwin,May 2026

LHR - LAX

First time flying with Virgin. It was everything I hoped it would be.
Virgin Atlantic
7.5
Good
689 reviews
Virgin Atlantic
7.5
Good
689 reviews
Check prices

Overall

7.5

Food

6.9

Boarding

7.7

Comfort

7.3

Entertainment

7.5

Crew

8.1

Reviews

1 / 20
10.0
Excellent

Edwin,May 2026

LHR - LAX

First time flying with Virgin. It was everything I hoped it would be.
Icelandair
7.0
Good
672 reviews
Virgin Atlantic
7.5
Good
689 reviews
Check prices

Overall

7.5

Food

6.9

Boarding

7.7

Comfort

7.3

Entertainment

7.5

Crew

8.1

Reviews

1 / 20
10.0
Excellent

Edwin,May 2026

LHR - LAX

First time flying with Virgin. It was everything I hoped it would be.
British Airways
6.7
Okay
8,041 reviews
Virgin Atlantic
7.5
Good
689 reviews
Check prices

Overall

7.5

Food

6.9

Boarding

7.7

Comfort

7.3

Entertainment

7.5

Crew

8.1

Reviews

1 / 20
10.0
Excellent

Edwin,May 2026

LHR - LAX

First time flying with Virgin. It was everything I hoped it would be.

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 42m. Fly via Delta, KLM, 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 British Airways 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 Virgin Atlantic and Icelandair, with the lowest prices starting at C$ 636 and C$ 658, respectively. Users have found that British Airways 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 (93%), Air France (93%), Delta (93%).

  • 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$ 2,135, our data shows the cheapest flight currently is C$ 479. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay C$ 1,272 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$ 895). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,720). 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
Hounslow
Slough
Marlow
Cobham
Leamington Spa
Northampton
Watford
Luton
High Wycombe
Stratford-upon-Avon
Moreton-in-Marsh

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.

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 11 June 2026.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapestC$ 624AverageC$ 925FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Virgin AtlanticCheapestC$ 636AverageC$ 989FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
IcelandairCheapestC$ 658AverageC$ 728FlexibilityNo cancel feeOn-time76%
Search Icelandair flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers 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?

900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Heathrow from Seattle today with Cheapflights!

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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