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$364+ Cheap flights from Seattle (SEA) to Heathrow (LHR)

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 7/7. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
Jun 26 — Jul 31
Fri 6/26
Fri 7/3
1 adult, Economy
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Find cheap flights from Seattle to Heathrow with Cheapflights

1. Tell us where you want to go

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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 Tuesday and return on a Monday

Cheap flight deals from Seattle to Heathrow

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 May 27, 2026.

This Mytrip deal was found by Cheapflights users on 5/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/13:00 pm
SEA
-
LHR
3 stops22h 20m
Multiple Airlines
Tue 6/96:40 am
LHR
-
SEA
2 stops22h 28m
Multiple Airlines
Deal found 5/26$896
This Kiwi.com deal was found by Cheapflights users on 5/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/237:00 pm
SEA
-
LHR
2 stops15h 50m
Multiple Airlines
Tue 9/2212:00 pm
LHR
-
SEA
1 stop13h 10m
Multiple Airlines
Deal found 5/26$897
This oojo deal was found by Cheapflights users on 5/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/183:55 pm
SEA
-
LHR
2 stops16h 30m
Scandinavian Airlines
Tue 9/87:05 am
LHR
-
SEA
2 stops14h 40m
Scandinavian Airlines
Deal found 5/26$898
This Gotogate deal was found by Cheapflights users on 5/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/108:20 pm
SEA
-
LHR
Nonstop9h 25m
Multiple Airlines
Tue 9/299:25 pm
LHR
-
SEA
1 stop28h 30m
Multiple Airlines
Deal found 5/26$899
This Cheapflightsfares deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/107:00 am
SEA
-
LHR
1 stop17h 30m
Lufthansa
Thu 8/206:30 am
LHR
-
SEA
2 stops20h 02m
Lufthansa
Deal found 5/22$900
This KLM deal was found by Cheapflights users on 5/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/186:20 pm
SEA
-
LHR
Nonstop9h 50m
KLM
Thu 8/276:30 am
LHR
-
SEA
1 stop13h 07m
KLM
Deal found 5/26$901
This KLM deal was found by Cheapflights users on 5/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/29:50 pm
SEA
-
LHR
Nonstop9h 45m
KLM
Sun 9/136:30 am
LHR
-
SEA
1 stop13h 17m
KLM
Deal found 5/26$902
This The Travel House deal was found by Cheapflights users on 5/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure The Travel House is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/48:00 am
SEA
-
LHR
1 stop17h 35m
Air Canada
Fri 8/147:25 am
LHR
-
SEA
1 stop17h 34m
Air Canada
Deal found 5/25$903
This Cheapflightsfares deal was found by Cheapflights users on 5/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/116:50 pm
SEA
-
LHR
1 stop17h 55m
Lufthansa
Wed 8/266:30 am
LHR
-
SEA
2 stops15h 52m
Lufthansa
Deal found 5/26$904
This Delta deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/1211:15 am
SEA
-
LHR
1 stop15h 25m
Delta
Tue 8/256:30 am
LHR
-
SEA
1 stop13h 07m
Delta
Deal found 5/22$905
This United Airlines deal was found by Cheapflights users on 5/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/1511:59 pm
SEA
-
LHR
1 stop23h 46m
United Airlines
Thu 9/310:50 am
LHR
-
SEA
1 stop14h 09m
United Airlines
Deal found 5/25$906
This Cheapflightsfares deal was found by Cheapflights users on 5/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/133:30 pm
SEA
-
LHR
2 stops18h 20m
Multiple Airlines
Thu 8/2710:50 am
LHR
-
SEA
1 stop14h 09m
Multiple Airlines
Deal found 5/26$907

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 May 27, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$896
(Alaska Airlines)

One-way from

$364
(Kiwi.com)

Popular in

June

Cheapest in

January

Average price

$975

Good round-trip deal

$1,048 or less

Good one-way deal

$491 or less
Provider with most accurate pricing for Seattle/Tacoma Intl-London Heathrow flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-London Heathrow flights.
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From Seattle/Tacoma Intl to London Heathrow
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One-way flight from Seattle/Tacoma Intl to London Heathrow
Search Deals
Highest demand for flights based on searches. 21% potential increase in price ($222 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($35 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in May 2026
Search Deals
Price to beat on a round-trip flight from Seattle/Tacoma Intl to London Heathrow.
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Price to beat on a one-way flight from Seattle/Tacoma Intl to London Heathrow.
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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 2,558,603 searches. Data last updated May 27, 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

Sat 8/15

11:59 pm-7:45 am

1 stop23h 46m

London Heathrow

Wed 8/19

10:50 am-4:59 pm

1 stop14h 09m

$906

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 8/12

9:45 pm-3:35 pm

Nonstop9h 50m

London Heathrow

Wed 8/19

5:45 pm-8:03 pm

Nonstop10h 18m

$930

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 8/27

9:45 pm-3:35 pm

Nonstop9h 50m

London Heathrow

Thu 9/17

11:40 am-2:00 pm

Nonstop10h 20m

$931

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 9/7

6:20 pm-12:10 pm

Nonstop9h 50m

London Heathrow

Sun 9/27

6:30 pm-8:53 pm

Nonstop10h 23m

$931

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 8/27

9:45 pm-3:35 pm

Nonstop9h 50m

London Heathrow

Fri 9/18

11:40 am-2:00 pm

Nonstop10h 20m

$931

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 8/17

12:36 pm-6:30 pm

2 stops21h 54m

London Heathrow

Mon 8/24

7:50 pm-1:45 pm

2 stops25h 55m

$951

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 8/7

9:45 pm-3:35 pm

Nonstop9h 50m

London Heathrow

Fri 8/21

6:30 am-11:37 am

1 stop13h 07m

$951

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 9/18

9:50 pm-3:35 pm

Nonstop9h 45m

London Heathrow

Mon 9/21

6:30 am-11:47 am

1 stop13h 17m

$952

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 10/15

8:10 pm-2:00 pm

Nonstop9h 50m

London Heathrow

Sun 10/18

6:30 am-11:52 am

1 stop13h 22m

$952

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 7/21

1:30 pm-11:00 am

1 stop13h 30m

London Heathrow

Wed 8/12

5:45 pm-8:03 pm

Nonstop10h 18m

$959

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/24

Showing 1-10 of 23 resultsSorted by cheapest first
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Compare providers for flights from Seattle to Heathrow

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Heathrow in May.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*3 stars
OvagoPrice Accuracy3 starsTrust Score*3 stars
JustAirTicketPrice Accuracy-Trust Score*1 star
CheapflightsfaresPrice Accuracy2 starsTrust Score*1 star
BusinessClassPrice Accuracy-Trust Score*3 stars
eDreamsPrice Accuracy2 starsTrust Score*3 stars
Justfly.comPrice Accuracy3 starsTrust Score*3 stars
Trip.comPrice Accuracy1 starTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Seattle-London Heathrow Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-London Heathrow Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-London Heathrow Airport flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-London Heathrow Airport flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-London Heathrow Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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?

Booking 64 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to London Heathrow Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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 $642). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of $1,205). 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 May 27, 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?

The best insider tips for Seattle to London Heathrow Airport flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to London Heathrow Airport trip
Our travel experts
Ramsey Qubein

Ramsey Qubein

Expert on LHR

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

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 May 27, 2026.
Read reviews from past customers who have flown Delta,Virgin Atlantic, andAir France from Seattle to London Heathrow Airport. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.9
Good
8,423 reviews

Comfort

7.8

Boarding

8.1

Overall

7.9

Entertainment

7.8

Food

7.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Delta
7.9
Good
8,423 reviews
Delta
7.9
Good
8,423 reviews

Comfort

7.8

Boarding

8.1

Overall

7.9

Entertainment

7.8

Food

7.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Virgin Atlantic
7.5
Good
689 reviews
Delta
7.9
Good
8,423 reviews

Comfort

7.8

Boarding

8.1

Overall

7.9

Entertainment

7.8

Food

7.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Air France
7.4
Good
1,592 reviews
Delta
7.9
Good
8,423 reviews

Comfort

7.8

Boarding

8.1

Overall

7.9

Entertainment

7.8

Food

7.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Icelandair
7.0
Good
662 reviews
Delta
7.9
Good
8,423 reviews

Comfort

7.8

Boarding

8.1

Overall

7.9

Entertainment

7.8

Food

7.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
British Airways
6.7
Okay
8,007 reviews
Delta
7.9
Good
8,423 reviews

Comfort

7.8

Boarding

8.1

Overall

7.9

Entertainment

7.8

Food

7.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional

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 20 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 13 airlines have flights from the Seattle airport to London Heathrow. It is only a 11.4 mi journey to Seattle/Tacoma Intl (SEA) from Seattle’s city center.

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

    For as low as $930, United Airlines can have you in London Heathrow Airport from Seattle in 9h 50m. The distance between Seattle and London Heathrow Airport is about 4783 mi. This flight may include one or multiple stops.

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

    Our cheapest airline available from Seattle to London Heathrow Airport is Aer Lingus. Our recent data shows that you can find tickets from as low as $481 on this airline. Additional options worth looking into are Icelandair and American Airlines, starting at $483 and $515 round-trip. Aer Lingus is currently priced 41% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from Seattle to London Heathrow Airport one-way?

    The cheapest airlines for a one-way flight from Seattle to London Heathrow Airport are Icelandair ($161), WestJet ($231), and Aer Lingus ($321).

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

    No one likes to see their flight delayed. When booking a flight from Seattle to London Heathrow Airport consider choosing KLM (96%), Air France (96%) or Delta (95%) as they are the most reliable in getting you off to your destination on time.

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

    Looking for the cheapest flight from Seattle to London Heathrow Airport? While on average our users pay $2,507, our data indicates the cheapest price to be $361. The most popular route (Seattle/Tacoma Intl - London Heathrow), is priced around $596.

  • 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 $642). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of $1,205). 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

Traveling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Ilford
Dorking
Hounslow
Winchester
Croydon
Gatwick
Southend-on-Sea
Harrow
Eastleigh
Dartford
Dover
Orpington
Watford
Northampton
Chipping Norton
Hayes
Kingston upon Thames
Eastbourne
Slough
Stansted

Browse thousands of different options on Cheapflights for your next trip

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Top 10 airlines flying from Seattle to Heathrow

Discover the top 10 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 2,558,603 searches. Data last updated May 27, 2026.
AirlineCheapestAverageFlexibilityOn-time
Aer LingusCheapest$481Average$628FlexibilityNo cancel feeOn-timeN/A
IcelandairCheapest$483Average$660FlexibilityNo cancel feeOn-time76%
American AirlinesCheapest$515Average$794FlexibilityNo cancel feeOn-time71%
British AirwaysCheapest$523Average$717FlexibilityNo cancel feeOn-time70%
Air FranceCheapest$532Average$765FlexibilityNo cancel feeOn-time77%
DeltaCheapest$545Average$863FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$547Average$842FlexibilityNo cancel feeOn-time69%
FinnairCheapest$556Average$694FlexibilityNo cancel feeOn-time76%
Virgin AtlanticCheapest$568Average$940FlexibilityNo cancel feeOn-time72%
Alaska AirlinesCheapest$589Average$1,027FlexibilityNo cancel feeOn-time75%

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