Find flights
Deals
When to book
Airlines
FAQs

Cheap flights from Seattle to London Heathrow Airport from C$ 515

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 1/2. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
22 Feb — 1 Mar1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London Heathrow are usually found in October or March, booked 83 days in advance, depart on a Sunday or Thursday 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 23 January 2026.

Wed 1/43:40 p.m.
SEA
-
LHR
1 stop12h 15m
Icelandair
Tue 5/51:05 p.m.
LHR
-
SEA
1 stop12h 50m
Icelandair
Deal found 21/1C$ 758
Mon 4/53:40 p.m.
SEA
-
LHR
1 stop12h 15m
Icelandair
Tue 12/51:05 p.m.
LHR
-
SEA
1 stop12h 50m
Icelandair
Deal found 21/1C$ 764
Wed 16/93:40 p.m.
SEA
-
LHR
1 stop12h 15m
Icelandair
Thu 24/91:05 p.m.
LHR
-
SEA
1 stop12h 50m
Icelandair
Deal found 22/1C$ 765
Fri 15/57:00 p.m.
SEA
-
LHR
1 stop17h 20m
Icelandair
Thu 21/59:25 p.m.
LHR
-
SEA
1 stop22h 20m
Icelandair
Deal found 20/1C$ 766
Wed 18/26:50 p.m.
SEA
-
LHR
Nonstop9h 30m
British Airways
Fri 27/27:50 a.m.
LHR
-
SEA
1 stop18h 30m
British Airways
Deal found 21/1C$ 778
Sun 22/26:50 p.m.
SEA
-
LHR
Nonstop9h 30m
British Airways
Wed 4/38:50 a.m.
LHR
-
SEA
1 stop17h 30m
British Airways
Deal found 22/1C$ 779
Sun 22/26:50 p.m.
SEA
-
LHR
Nonstop9h 30m
British Airways
Tue 3/33:35 p.m.
LHR
-
SEA
1 stop34h 45m
British Airways
Deal found 22/1C$ 789
Sun 1/33:40 p.m.
SEA
-
LHR
1 stop12h 10m
Lufthansa
Sat 7/38:15 p.m.
LHR
-
SEA
1 stop25h 05m
Lufthansa
Deal found 22/1C$ 791
Wed 9/98:20 p.m.
SEA
-
LHR
Nonstop9h 25m
British Airways
Wed 28/1012:10 p.m.
LHR
-
SEA
1 stop14h 10m
British Airways
Deal found 21/1C$ 800
Tue 25/81:35 p.m.
SEA
-
LHR
Nonstop9h 15m
British Airways
Wed 7/106:15 a.m.
LHR
-
SEA
1 stop18h 55m
British Airways
Deal found 22/1C$ 802

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 23 January 2026.

Round-trip from

C$ 758

One-way from

C$ 515

Popular in

June

Cheapest in

October

Average price

C$ 957

Good round-trip deal

C$ 1,007 or less

Good one-way deal

C$ 568 or less
Icelandair
  • Icelandair
  • 1/4-5/5
  • 2 total stops
  • 25h 05m total
  • Seattle to London
Search Deals
Lufthansa
  • Lufthansa
  • 1/2
  • 2 total stops
  • 31h 30m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 18% potential increase in price (C$ 345 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (C$ 58 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 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 23 January 2026.
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

Sun 22/2

6:50 p.m.-12:20 p.m.

Nonstop9h 30m

London Heathrow

Fri 6/3

9:25 a.m.-11:30 a.m.

Nonstop10h 05m

C$ 819

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 21/2

8:00 p.m.-11:50 a.m.

1 stop31h 50m

London Heathrow

Sat 28/2

4:40 p.m.-1:20 p.m.

1 stop28h 40m

C$ 830

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 12/3

7:25 p.m.-11:55 a.m.

Nonstop9h 30m

London Heathrow

Thu 19/3

6:30 a.m.-12:35 p.m.

1 stop13h 05m

C$ 851

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 21/2

6:10 a.m.-7:05 a.m.

1 stop16h 55m

London Heathrow

Sat 28/2

6:30 a.m.-11:40 a.m.

1 stop13h 10m

C$ 858

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 29/4

6:20 a.m.-11:35 a.m.

2 stops21h 15m

London Heathrow

Tue 5/5

1:40 p.m.-10:52 p.m.

1 stop17h 12m

C$ 862

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 13/3

7:15 a.m.-4:50 p.m.

1 stop26h 35m

London Heathrow

Tue 31/3

11:45 a.m.-11:45 a.m.

1 stop32h 00m

C$ 870

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 1/3

7:00 a.m.-11:20 a.m.

2 stops20h 20m

London Heathrow

Sat 7/3

1:30 p.m.-9:16 p.m.

2 stops39h 46m

C$ 888

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 13/3

7:15 a.m.-4:50 p.m.

1 stop26h 35m

London Heathrow

Thu 2/4

6:30 a.m.-11:45 a.m.

1 stop13h 15m

C$ 892

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 28/4

3:48 p.m.-12:20 p.m.

1 stop12h 32m

London Heathrow

Fri 8/5

11:25 a.m.-11:29 p.m.

2 stops20h 04m

C$ 896

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 19/4

8:20 p.m.-1:45 p.m.

Nonstop9h 25m

C$ 518

Flights are sorted by cheapest round-trip flights first.

Deals found on 22/1

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 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 16 January 2026.

The best time to book flights from Seattle to London Heathrow Airport is 83 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$ 686). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,094). 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 23 January 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 23 January 2026.
Read through reviews of airlines operating flights from Seattle to London Heathrow Airport, such as Virgin Atlantic,Icelandair, andIberia. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Virgin Atlantic
7.5
Good
678 reviews
Check prices

Food

6.9

Entertainment

7.6

Comfort

7.3

Crew

8.2

Boarding

7.7

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
678 reviews
Virgin Atlantic
7.5
Good
678 reviews
Check prices

Food

6.9

Entertainment

7.6

Comfort

7.3

Crew

8.2

Boarding

7.7

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!
Icelandair
7.1
Good
602 reviews
Virgin Atlantic
7.5
Good
678 reviews
Check prices

Food

6.9

Entertainment

7.6

Comfort

7.3

Crew

8.2

Boarding

7.7

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!
Iberia
7.0
Good
3,098 reviews
Virgin Atlantic
7.5
Good
678 reviews
Check prices

Food

6.9

Entertainment

7.6

Comfort

7.3

Crew

8.2

Boarding

7.7

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
7,690 reviews
Virgin Atlantic
7.5
Good
678 reviews
Check prices

Food

6.9

Entertainment

7.6

Comfort

7.3

Crew

8.2

Boarding

7.7

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?

    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 13 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 4 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 30m. Fly via British Airways, United Airlines, or KLM 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 Iberia is currently your cheapest option to London Heathrow Airport, with prices starting at C$ 627. Additional round-trip tickets that might be worth considering are offered by Icelandair and Virgin Atlantic, with the lowest prices starting at C$ 652 and C$ 697, respectively. Users have found that Iberia 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: KLM (81%), Delta (81%), Virgin Atlantic (81%).

  • 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$ 921, our data shows the cheapest flight currently is C$ 449. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay C$ 802 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$ 686). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of C$ 1,094). 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
Sutton
Twickenham
Gatwick
Slough
Marlow
Cobham
Milton Keynes
Leamington Spa
Romford
Watford
Bedford
Luton
Stratford-upon-Avon
Hounslow

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 4 airlines flying from Seattle to Heathrow

Discover the top 4 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 23 January 2026.
AirlineCheapestAverageFlexibilityOn-time
IberiaCheapestC$ 627AverageC$ 857FlexibilityNo cancel feeOn-time77%
Search Iberia flights
IcelandairCheapestC$ 652AverageC$ 721FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Virgin AtlanticCheapestC$ 697AverageC$ 951FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapestC$ 701AverageC$ 975FlexibilityNo cancel feeOn-time70%
Search British Airways 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.

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.