$412+ 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 5/5. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
May 7 — May 141
Round-trip
1 adult, Economy
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Find cheap flights from Seattle to Heathrow with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.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
Best
Last-minute
One-way
Cheapest flights from Seattle to HeathrowExplore 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 April 7, 2026.
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 April 7, 2026.
This Mytrip deal was found by Cheapflights users on 4/3. 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.
Sun 4/197:00 pm
SEA
- LHR
2 stops18h 20m
Multiple Airlines
Fri 4/246:40 am
LHR
- SEA
2 stops22h 00m
Multiple Airlines
Deal found 4/3![Multiple Airlines logo]()
$648
This KAYAK deal was found by Cheapflights users on 4/5. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/213:55 pm
SEA
- LHR
1 stop33h 25m
Scandinavian Airlines
Mon 8/246:40 am
LHR
- SEA
2 stops39h 05m
Scandinavian Airlines
Deal found 4/5![Scandinavian Airlines logo]()
$651
This KAYAK deal was found by Cheapflights users on 4/4. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/1812:40 pm
SEA
- LHR
2 stops43h 20m
Scandinavian Airlines
Thu 5/216:40 am
LHR
- SEA
2 stops39h 05m
Scandinavian Airlines
Deal found 4/4![Scandinavian Airlines logo]()
$660
This Mytrip deal was found by Cheapflights users on 4/5. 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 4/203:40 pm
SEA
- LHR
2 stops21h 40m
Multiple Airlines
Tue 4/286:40 am
LHR
- SEA
2 stops22h 00m
Multiple Airlines
Deal found 4/5![Multiple Airlines logo]()
$672
This Mytrip deal was found by Cheapflights users on 4/5. 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.
Sun 5/37:00 pm
SEA
- LHR
3 stops28h 40m
Multiple Airlines
Sun 5/108:55 pm
LHR
- SEA
3 stops29h 00m
Multiple Airlines
Deal found 4/5![Multiple Airlines logo]()
$681
This Mytrip deal was found by Cheapflights users on 4/5. 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.
Sat 4/253:40 pm
SEA
- LHR
2 stops21h 40m
Multiple Airlines
Sat 5/26:10 pm
LHR
- SEA
3 stops34h 30m
Multiple Airlines
Deal found 4/5![Multiple Airlines logo]()
$685
This Mytrip deal was found by Cheapflights users on 4/6. 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 5/43:40 pm
SEA
- LHR
2 stops20h 15m
Multiple Airlines
Mon 5/116:40 am
LHR
- SEA
2 stops19h 15m
Multiple Airlines
Deal found 4/6![Multiple Airlines logo]()
$689
This oojo deal was found by Cheapflights users on 4/7. 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.
Fri 10/23:55 pm
SEA
- LHR
1 stop33h 25m
Scandinavian Airlines
Sat 10/105:30 pm
LHR
- SEA
2 stops28h 15m
Scandinavian Airlines
Deal found 4/7![Scandinavian Airlines logo]()
$692
Best flights from Seattle to HeathrowDiscover carefully curated flight deals from Seattle to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 7, 2026.
Discover carefully curated flight deals from Seattle to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 7, 2026.
This KLM deal was found by Cheapflights users on 4/5. 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.
Sun 9/206:20 pm
SEA
- LHR
Nonstop9h 50m
KLM
Wed 9/3011:45 am
LHR
- SEA
1 stop12h 50m
KLM
Deal found 4/5![KLM logo]()
$898
This United Airlines deal was found by Cheapflights users on 4/2. 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.
Tue 8/41:55 pm
SEA
- LHR
1 stop14h 00m
United Airlines
Wed 8/129:00 am
LHR
- SEA
1 stop15h 59m
United Airlines
Deal found 4/2![United Airlines logo]()
$922
This Scandinavian Airlines deal was found by Cheapflights users on 4/4. 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 Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/1910:00 am
SEA
- LHR
2 stops22h 00m
Scandinavian Airlines
Tue 5/266:40 am
LHR
- SEA
1 stop15h 05m
Scandinavian Airlines
Deal found 4/4![Scandinavian Airlines logo]()
$959
This Delta deal was found by Cheapflights users on 4/5. 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 4/299:45 pm
SEA
- LHR
Nonstop9h 50m
Delta
Tue 5/56:30 am
LHR
- SEA
1 stop18h 00m
Delta
Deal found 4/5![Delta logo]()
$998
This KLM deal was found by Cheapflights users on 4/6. 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 9/296:20 pm
SEA
- LHR
Nonstop9h 50m
KLM
Tue 10/208:40 am
LHR
- SEA
1 stop15h 59m
KLM
Deal found 4/6![KLM logo]()
$898
This KLM deal was found by Cheapflights users on 4/3. 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
Fri 8/2111:40 am
LHR
- SEA
Nonstop10h 20m
KLM
Deal found 4/3![KLM logo]()
$928
This Delta deal was found by Cheapflights users on 4/5. 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.
Sat 8/226:20 pm
SEA
- LHR
Nonstop9h 50m
Delta
Mon 8/315:45 pm
LHR
- SEA
Nonstop10h 18m
Delta
Deal found 4/5![Delta logo]()
$1,027
This KLM deal was found by Cheapflights users on 4/3. 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 8/46:20 pm
SEA
- LHR
Nonstop9h 50m
KLM
Tue 8/186:30 am
LHR
- SEA
1 stop13h 07m
KLM
Deal found 4/3![KLM logo]()
$965
This KLM deal was found by Cheapflights users on 4/6. 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.
Sun 7/266:20 pm
SEA
- LHR
Nonstop9h 50m
KLM
Wed 8/1211:40 am
LHR
- SEA
Nonstop10h 20m
KLM
Deal found 4/6![KLM logo]()
$993
This KLM deal was found by Cheapflights users on 4/6. 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 5/126:20 pm
SEA
- LHR
Nonstop9h 50m
KLM
Tue 5/2611:40 am
LHR
- SEA
Nonstop10h 20m
KLM
Deal found 4/6![KLM logo]()
$993
This KLM deal was found by Cheapflights users on 4/6. 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.
Mon 4/206:20 pm
SEA
- LHR
Nonstop9h 50m
KLM
Thu 4/3011:45 am
LHR
- SEA
1 stop12h 45m
KLM
Deal found 4/6![KLM logo]()
$998
This KLM deal was found by Cheapflights users on 4/5. 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.
Thu 8/278:10 pm
SEA
- LHR
Nonstop9h 50m
KLM
Sat 8/2911:40 am
LHR
- SEA
Nonstop10h 20m
KLM
Deal found 4/5![KLM logo]()
$1,027
Last-minute flights from Seattle to HeathrowDiscover last-minute flight deals from Seattle to Heathrow. Data last updated April 7, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Heathrow. Data last updated April 7, 2026 and is based on user searches.
This Mytrip deal was found by Cheapflights users on 4/4. 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.
Thu 4/167:00 pm
SEA
- LHR
2 stops18h 20m
Multiple Airlines
Thu 4/235:30 pm
LHR
- SEA
3 stops32h 25m
Multiple Airlines
Deal found 4/4![Multiple Airlines logo]()
$702
This Mytrip deal was found by Cheapflights users on 4/3. 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.
Sun 4/197:00 pm
SEA
- LHR
2 stops18h 20m
Multiple Airlines
Fri 4/246:40 am
LHR
- SEA
2 stops22h 00m
Multiple Airlines
Deal found 4/3![Multiple Airlines logo]()
$648
This Mytrip deal was found by Cheapflights users on 4/5. 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 4/203:40 pm
SEA
- LHR
2 stops21h 40m
Multiple Airlines
Tue 4/286:40 am
LHR
- SEA
2 stops22h 00m
Multiple Airlines
Deal found 4/5![Multiple Airlines logo]()
$672
This Mytrip deal was found by Cheapflights users on 4/5. 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.
Sat 4/253:40 pm
SEA
- LHR
2 stops21h 40m
Multiple Airlines
Sat 5/26:10 pm
LHR
- SEA
3 stops34h 30m
Multiple Airlines
Deal found 4/5![Multiple Airlines logo]()
$685
This Mytrip deal was found by Cheapflights users on 4/5. 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.
Sun 5/37:00 pm
SEA
- LHR
3 stops28h 40m
Multiple Airlines
Sun 5/108:55 pm
LHR
- SEA
3 stops29h 00m
Multiple Airlines
Deal found 4/5![Multiple Airlines logo]()
$681
This Mytrip deal was found by Cheapflights users on 4/6. 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 5/43:40 pm
SEA
- LHR
2 stops20h 15m
Multiple Airlines
Mon 5/116:40 am
LHR
- SEA
2 stops19h 15m
Multiple Airlines
Deal found 4/6![Multiple Airlines logo]()
$689
This eDestinos deal was found by Cheapflights users on 4/4. 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 eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/43:40 pm
SEA
- LHR
1 stop12h 15m
Icelandair
Mon 5/119:25 pm
LHR
- SEA
1 stop31h 15m
Icelandair
Deal found 4/4![Icelandair logo]()
$708
This KAYAK deal was found by Cheapflights users on 4/4. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/1812:40 pm
SEA
- LHR
2 stops43h 20m
Scandinavian Airlines
Thu 5/216:40 am
LHR
- SEA
2 stops39h 05m
Scandinavian Airlines
Deal found 4/4![Scandinavian Airlines logo]()
$660
One-way flights from Seattle to HeathrowSearch for one-way flight options from Seattle to Heathrow. Find affordable one-way fares based on user searches. Data last updated April 7, 2026.
Search for one-way flight options from Seattle to Heathrow. Find affordable one-way fares based on user searches. Data last updated April 7, 2026.
This Kiwi.com deal was found by Cheapflights users on 4/6. 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.
Tue 5/57:00 pm
SEA
- LHR
3 stops18h 35m
Multiple Airlines
Deal found 4/6![Multiple Airlines logo]()
$412
This Kiwi.com deal was found by Cheapflights users on 4/5. 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.
Wed 4/297:00 pm
SEA
- LHR
2 stops37h 25m
Multiple Airlines
Deal found 4/5![Multiple Airlines logo]()
$413
This Mytrip deal was found by Cheapflights users on 4/3. 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.
Sun 5/317:20 pm
SEA
- LHR
3 stops32h 45m
Multiple Airlines
Deal found 4/3![Multiple Airlines logo]()
$414
This Mytrip deal was found by Cheapflights users on 4/5. 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.
Sat 5/165:50 am
SEA
- LHR
3 stops22h 15m
Multiple Airlines
Deal found 4/5![Multiple Airlines logo]()
$417
This Kiwi.com deal was found by Cheapflights users on 4/4. 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 5/37:00 pm
SEA
- LHR
3 stops18h 20m
Multiple Airlines
Deal found 4/4![Multiple Airlines logo]()
$419
This Kiwi.com deal was found by Cheapflights users on 4/6. 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.
Sat 5/2311:25 pm
SEA
- LHR
2 stops37h 55m
Multiple Airlines
Deal found 4/6![Multiple Airlines logo]()
$421
This Kiwi.com deal was found by Cheapflights users on 4/5. 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.
Wed 6/37:00 pm
SEA
- LHR
2 stops30h 35m
Multiple Airlines
Deal found 4/5![Multiple Airlines logo]()
$422
This Kiwi.com deal was found by Cheapflights users on 4/3. 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.
Thu 4/307:00 pm
SEA
- LHR
2 stops30h 20m
Multiple Airlines
Deal found 4/3![Multiple Airlines logo]()
$423
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 April 7, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $648 (Mytrip) |
One-way from | $412 (Kiwi.com) |
Popular in | June |
Cheapest in | January |
Average price | $782 |
Good round-trip deal | $886 or less |
Good one-way deal | $511 or less |
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 April 7, 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
Cheapest round-trip
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sun 9/20
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Wed 9/30
11:45 am-4:35 pm
1 stop12h 50m
$898
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Tue 9/29
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Tue 10/20
8:40 am-4:39 pm
1 stop15h 59m
$898
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Tue 8/4
1:55 pm-11:55 am
1 stop14h 00m
London Heathrow
Wed 8/12
9:00 am-4:59 pm
1 stop15h 59m
$922
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Tue 8/18
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Fri 8/21
11:40 am-2:00 pm
Nonstop10h 20m
$928
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Tue 5/19
10:00 am-4:00 pm
2 stops22h 00m
London Heathrow
Tue 5/26
6:40 am-1:45 pm
1 stop15h 05m
$959
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Tue 8/4
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Tue 8/18
6:30 am-11:37 am
1 stop13h 07m
$965
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sun 7/26
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Wed 8/12
11:40 am-2:00 pm
Nonstop10h 20m
$993
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Tue 5/12
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Tue 5/26
11:40 am-2:00 pm
Nonstop10h 20m
$993
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Wed 4/29
9:45 pm-3:35 pm
Nonstop9h 50m
London Heathrow
Tue 5/5
6:30 am-4:30 pm
1 stop18h 00m
$998
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Mon 4/20
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Thu 4/30
11:45 am-4:30 pm
1 stop12h 45m
$998
Showing 1-10 of 24 resultsSorted by cheapest first
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 April.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy2 stars | Trust Score*2 stars | |
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy1 star | Trust Score*2 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- 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.
SEA-LHR
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
Prices
Airlines
Delays
More
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 April 3, 2026.
Booking 65 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, October is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of $499). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of $779). 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 April 7, 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 often are flights from Seattle to London delayed?
About 15% of weekly flights between Seattle and London have experienced delays in the past year, with the average delay time being 126 minutes.
What is the most punctual flight time for Seattle to London flights?
Historically, flights departing in the early afternoon are less likely to be delayed, whereas flights leaving at night tend to experience delays more often.
What day of the week experiences the fewest flight delays on this route?
Tuesday tends to have the lowest number of delays on this route, whereas Wednesday has historically faced a higher average of delays compared to other days of the week.
Which airline has the best punctuality record on Seattle to London flights?
Over the last year, Virgin Atlantic have had the lowest number of delays on this route, with just 7% of flights being delayed.
What’s the top layover airport for flights from Seattle to London Heathrow Airport?
Share of 1-stop round-trip flights from Seattle to London Heathrow Airport chosen by Cheapflights users in the past 12 months, using the same layover each way.
Reykjavik (KEF) – chosen by Cheapflights users on 86% of 1-stop itineraries from Seattle to London Heathrow Airport on Cheapflights.
What’s the cheapest layover airport for flights from Seattle to London Heathrow Airport?
Average round-trip fare for 1-stop flights from Seattle to London Heathrow Airport, chosen by Cheapflights users in the past 12 months, with the same layover each way.
Montreal (YUL) is the most affordable 1-stop option, with an average round-trip price of $631.
What’s the fastest layover option from Seattle to London Heathrow Airport?
Shortest average travel time for 1-stop one-way flights from Seattle to London Heathrow Airport, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.
Flights via Reykjavik (KEF) have the shortest average one-way travel time for 1-stop routes: 12h 26m.
Which airport typically offers the quickest layover for flights from Seattle to London Heathrow Airport?
Average layover duration for 1-stop one-way flights from Seattle to London Heathrow Airport, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.
Flights via Reykjavik (KEF) offer the fastest connection on this route, with an average layover time of 2h 06m.
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
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 April 7, 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.
Boarding
8.1
Comfort
7.9
Overall
7.9
Entertainment
7.8
Crew
8.5
Food
7.2
Reviews
1 / 20
6.0
GoodJim,Nov 2025
AVL - ATL
Boarding
8.1
Comfort
7.9
Overall
7.9
Entertainment
7.8
Crew
8.5
Food
7.2
Reviews
1 / 20
6.0
GoodJim,Nov 2025
AVL - ATL
Boarding
8.1
Comfort
7.9
Overall
7.9
Entertainment
7.8
Crew
8.5
Food
7.2
Reviews
1 / 20
6.0
GoodJim,Nov 2025
AVL - ATL
Boarding
8.1
Comfort
7.9
Overall
7.9
Entertainment
7.8
Crew
8.5
Food
7.2
Reviews
1 / 20
6.0
GoodJim,Nov 2025
AVL - ATL
Boarding
8.1
Comfort
7.9
Overall
7.9
Entertainment
7.8
Crew
8.5
Food
7.2
Reviews
1 / 20
6.0
GoodJim,Nov 2025
AVL - ATL
Boarding
8.1
Comfort
7.9
Overall
7.9
Entertainment
7.8
Crew
8.5
Food
7.2
Reviews
1 / 20
6.0
GoodJim,Nov 2025
AVL - ATL
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.
Traveling to a place near London Heathrow Airport?
Book flights to London Heathrow Airport if you plan to visit one of these locationsIlford
Hounslow
Croydon
Gatwick
Southend-on-Sea
Harrow
Eastleigh
Dartford
Dover
Winchester
Orpington
Watford
Northampton
Borehamwood
Broadway
Chipping Norton
Hayes
Kingston upon Thames
Eastbourne
Sutton
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Other flights to Heathrow
Explore flights to Heathrow departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on April 7, 2026.
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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 April 7, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$481 | Average$725 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$482 | Average$603 | FlexibilityNo cancel fee | On-time76% | |
| Cheapest$515 | Average$782 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$527 | Average$721 | FlexibilityNo cancel fee | On-time70% | |
| Cheapest$532 | Average$782 | FlexibilityNo cancel fee | On-time77% | |
| Cheapest$532 | Average$771 | FlexibilityNo cancel fee | On-time77% | |
| Cheapest$547 | Average$824 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$554 | Average$798 | FlexibilityNo cancel fee | On-time77% | |
| Cheapest$556 | Average$694 | FlexibilityNo cancel fee | On-time76% | |
| Cheapest$556 | Average$858 | FlexibilityNo cancel fee | On-timeN/A |