Cheap flights from Seattle to London Heathrow Airport from £252
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 14/4. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
29 Jan — 5 Feb1
Return
1 adult
Economy
Return
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 65 days in advance, depart on a Tuesday or Thursday and return on a Wednesday
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 30 December 2025.
Mon 29/1214:35SEA - LHR
1 stop20h 55mIcelandair
Mon 12/120:35LHR - SEA
1 stop28h 25mIcelandair
Deal found 28/12£545
Tue 30/1214:00SEA - LHR
1 stop16h 45mLufthansa
Fri 16/107:40LHR - SEA
1 stop13h 40mLufthansa
Deal found 29/12£580
Wed 31/1215:10SEA - LHR
1 stop13h 50mLufthansa
Thu 8/120:15LHR - SEA
1 stop25h 05mLufthansa
Deal found 27/12£590
Wed 31/1210:05SEA - LHR
1 stop17h 45mLufthansa
Mon 12/118:30LHR - SEA
2 stops31h 44mLufthansa
Deal found 30/12£595
Tue 30/1220:00SEA - LHR
2 stops27h 10mAir Canada
Tue 13/115:00LHR - SEA
2 stops15h 06mAir Canada
Deal found 29/12£599
Sun 28/1215:40SEA - LHR
2 stops55h 30mMultiple Airlines
Tue 13/116:40LHR - SEA
1 stop28h 40mMultiple Airlines
Deal found 28/12£600
Tue 30/1219:20SEA - LHR
Nonstop9h 30mKLM
Fri 16/106:30LHR - SEA
1 stop13h 20mKLM
Deal found 29/12£602
Sun 28/1220:00SEA - LHR
2 stops51h 10mAir Canada
Tue 13/115:00LHR - SEA
2 stops26h 15mAir Canada
Deal found 28/12£602
Wed 31/1210:05SEA - LHR
2 stops16h 05mMultiple Airlines
Thu 8/120:15LHR - SEA
1 stop25h 05mMultiple Airlines
Deal found 27/12£605
Sun 28/1218:10SEA - LHR
1 stop28h 55mDelta
Tue 13/106:30LHR - SEA
1 stop13h 20mDelta
Deal found 28/12£606
Best flights from Seattle to Heathrow
Discover carefully curated flight deals from Seattle to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 30 December 2025.
Sat 18/415:40SEA - LHR
1 stop12h 15mIcelandair
Mon 27/421:25LHR - SEA
1 stop28h 30mIcelandair
Deal found 28/12£445
Sun 25/116:45SEA - LHR
Nonstop9h 45mDelta
Thu 5/206:30LHR - SEA
1 stop13h 10mDelta
Deal found 28/12£456
Mon 2/218:25SEA - LHR
Nonstop9h 30mKLM
Mon 16/206:30LHR - SEA
1 stop13h 10mKLM
Deal found 28/12£456
Mon 9/319:25SEA - LHR
Nonstop9h 30mMultiple Airlines
Mon 16/306:20LHR - SEA
1 stop14h 45mMultiple Airlines
Deal found 29/12£461
Thu 12/205:45SEA - LHR
1 stop22h 05mUnited Airlines
Thu 19/206:50LHR - SEA
2 stops20h 13mUnited Airlines
Deal found 29/12£463
Wed 18/317:40SEA - LHR
Nonstop9h 50mDelta
Tue 31/306:30LHR - SEA
1 stop18h 00mDelta
Deal found 30/12£456
Sat 14/217:20SEA - LHR
1 stop30h 05mUnited Airlines
Sun 22/214:30LHR - SEA
1 stop26h 45mUnited Airlines
Deal found 28/12£467
Wed 4/316:45SEA - LHR
Nonstop9h 45mDelta
Thu 19/306:30LHR - SEA
1 stop13h 05mDelta
Deal found 29/12£456
Tue 21/408:55SEA - LHR
2 stops16h 25mUnited Airlines
Wed 29/409:00LHR - SEA
1 stop15h 59mUnited Airlines
Deal found 29/12£471
Sun 8/317:40SEA - LHR
Nonstop9h 50mDelta
Wed 18/306:30LHR - SEA
1 stop13h 05mDelta
Deal found 29/12£456
Sun 19/418:20SEA - LHR
Nonstop9h 50mDelta
Wed 29/409:55LHR - SEA
1 stop14h 35mDelta
Deal found 29/12£467
Wed 22/418:20SEA - LHR
Nonstop9h 50mDelta
Wed 29/409:55LHR - SEA
1 stop14h 35mDelta
Deal found 29/12£467
Direct flights from Seattle to Heathrow
Explore direct flight options from Seattle to Heathrow based on user searches, and compare prices and availability for your desired travel dates. Data last updated 30 December 2025.
Tue 27/116:45SEA - LHR
Nonstop9h 45mVirgin Atlantic
Tue 3/212:20LHR - SEA
Nonstop10h 25mVirgin Atlantic
Deal found 28/12£455
Sun 15/218:50SEA - LHR
Nonstop9h 30mBritish Airways
Thu 26/214:55LHR - SEA
Nonstop10h 00mBritish Airways
Deal found 30/12£467
Sun 29/318:20SEA - LHR
Nonstop9h 50mVirgin Atlantic
Wed 15/411:40LHR - SEA
Nonstop10h 20mVirgin Atlantic
Deal found 29/12£467
Sat 14/319:50SEA - LHR
Nonstop9h 30mFinnair
Sat 21/309:25LHR - SEA
Nonstop10h 05mFinnair
Deal found 28/12£471
Mon 26/116:45SEA - LHR
Nonstop9h 45mVirgin Atlantic
Mon 9/212:20LHR - SEA
Nonstop10h 25mVirgin Atlantic
Deal found 29/12£474
Wed 25/218:50SEA - LHR
Nonstop9h 30mBritish Airways
Sun 1/314:55LHR - SEA
Nonstop10h 00mBritish Airways
Deal found 29/12£476
Sun 25/116:45SEA - LHR
Nonstop9h 45mVirgin Atlantic
Sat 7/215:05LHR - SEA
Nonstop10h 05mVirgin Atlantic
Deal found 28/12£476
Mon 26/116:45SEA - LHR
Nonstop9h 45mKLM
Mon 2/212:20LHR - SEA
Nonstop10h 25mKLM
Deal found 29/12£477
Mon 20/420:20SEA - LHR
Nonstop9h 25mBritish Airways
Tue 28/416:30LHR - SEA
Nonstop9h 55mBritish Airways
Deal found 30/12£479
Mon 6/418:20SEA - LHR
Nonstop9h 50mDelta
Thu 7/517:40LHR - SEA
Nonstop10h 26mDelta
Deal found 29/12£489
Wed 11/319:50SEA - LHR
Nonstop9h 30mBritish Airways
Mon 16/314:55LHR - SEA
Nonstop10h 00mBritish Airways
Deal found 29/12£503
Last-minute flights from Seattle to Heathrow
Discover last-minute flight deals from Seattle to Heathrow. Data last updated 30 December 2025 and is based on user searches.
Wed 14/114:35SEA - LHR
2 stops21h 20mMultiple Airlines
Wed 21/106:40LHR - SEA
2 stops18h 20mMultiple Airlines
Deal found 28/12£428
Sun 25/114:10SEA - LHR
1 stop13h 05mLufthansa
Sat 7/206:30LHR - SEA
1 stop13h 40mLufthansa
Deal found 28/12£424
Sun 25/105:50SEA - LHR
2 stops17h 20mLufthansa
Sun 1/207:40LHR - SEA
1 stop13h 40mLufthansa
Deal found 28/12£436
Mon 26/108:10SEA - LHR
1 stop14h 30mAustrian Airlines
Mon 2/206:00LHR - SEA
2 stops22h 57mAustrian Airlines
Deal found 29/12£419
Mon 26/115:40SEA - LHR
1 stop12h 10mLufthansa
Mon 2/206:30LHR - SEA
1 stop13h 40mLufthansa
Deal found 29/12£432
Tue 27/110:58SEA - LHR
1 stop12h 57mBrussels Airlines
Tue 3/206:50LHR - SEA
2 stops22h 07mBrussels Airlines
Deal found 29/12£422
Wed 28/114:10SEA - LHR
1 stop13h 05mLufthansa
Wed 4/207:40LHR - SEA
1 stop13h 40mLufthansa
Deal found 29/12£423
Wed 28/114:10SEA - LHR
1 stop13h 05mLufthansa
Mon 2/206:30LHR - SEA
1 stop13h 40mLufthansa
Deal found 28/12£433
Thu 29/114:10SEA - LHR
1 stop13h 05mLufthansa
Sun 1/207:40LHR - SEA
1 stop13h 40mLufthansa
Deal found 28/12£424
Sat 31/105:50SEA - LHR
2 stops20h 20mMultiple Airlines
Fri 13/206:35LHR - SEA
1 stop14h 45mMultiple Airlines
Deal found 28/12£436
One-way flights from Seattle to Heathrow
Search for one-way flight options from Seattle to Heathrow. Find affordable one-way fares based on user searches. Data last updated 30 December 2025.
Tue 14/418:45SEA - LHR
1 stop13h 10mAer Lingus
Deal found 29/12£252
Tue 3/308:55SEA - LHR
1 stop16h 25mMultiple Airlines
Deal found 28/12£253
Wed 13/507:05SEA - LHR
1 stop21h 00mWestJet
Deal found 28/12£254
Mon 2/314:35SEA - LHR
3 stops22h 45mMultiple Airlines
Deal found 29/12£255
Thu 15/114:35SEA - LHR
3 stops22h 30mMultiple Airlines
Deal found 28/12£256
Mon 12/114:35SEA - LHR
3 stops34h 20mMultiple Airlines
Deal found 29/12£258
Tue 13/114:35SEA - LHR
2 stops16h 00mMultiple Airlines
Deal found 28/12£259
Tue 14/418:45SEA - LHR
2 stops29h 25mMultiple Airlines
Deal found 28/12£260
Fri 27/220:14SEA - LHR
3 stops36h 11mMultiple Airlines
Deal found 29/12£261
Fri 16/110:09SEA - LHR
1 stop26h 01mMultiple Airlines
Deal found 29/12£264
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 30 December 2025.
Customise 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 858,174 searches. Data last updated 30 December 2025.
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
Sat 18/4
15:40-11:55
1 stop12h 15m
London Heathrow
Mon 27/4
21:25-17:55
1 stop28h 30m
£445
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sun 25/1
16:45-10:30
Nonstop9h 45m
London Heathrow
Thu 5/2
06:30-11:40
1 stop13h 10m
£456
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Mon 2/2
18:25-11:55
Nonstop9h 30m
London Heathrow
Mon 16/2
06:30-11:40
1 stop13h 10m
£456
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Wed 18/3
17:40-10:30
Nonstop9h 50m
London Heathrow
Tue 31/3
06:30-16:30
1 stop18h 00m
£456
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Wed 4/3
16:45-10:30
Nonstop9h 45m
London Heathrow
Thu 19/3
06:30-12:35
1 stop13h 05m
£456
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sun 8/3
17:40-10:30
Nonstop9h 50m
London Heathrow
Wed 18/3
06:30-12:35
1 stop13h 05m
£456
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Mon 9/3
19:25-11:55
Nonstop9h 30m
London Heathrow
Mon 16/3
06:20-14:05
1 stop14h 45m
£461
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Thu 12/2
05:45-11:50
1 stop22h 05m
London Heathrow
Thu 19/2
06:50-19:03
2 stops20h 13m
£463
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sat 14/2
17:20-07:25
1 stop30h 05m
London Heathrow
Sun 22/2
14:30-09:15
1 stop26h 45m
£467
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sun 19/4
18:20-12:10
Nonstop9h 50m
London Heathrow
Wed 29/4
09:55-16:30
1 stop14h 35m
£467
Flights are sorted by cheapest return flights first.
Deals found on 30/12
Showing 1-10 of 24 results
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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 return 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 return flight from Seattle to Heathrow. Price data was last updated on 26 December 2025.
The price you pay for your flight from Seattle to London Heathrow Airport may vary depending on when you book. For the best chance of a lower fare, look to book 65 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
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 £369). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £585). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
What is the cheapest time of day to fly from SEA to LHR?
Find hourly flight availability from Seattle to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 30 December 2025.
When flying from Seattle to London Heathrow Airport, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
Weekly flight availability from Seattle to London Heathrow Airport
Explore weekly flight availability from Seattle to Heathrow. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 30 December 2025.
The most flights from SEA to LHR are scheduled on a Tuesday (21 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (6 on average).
How often are flights from Seattle to London delayed?
About 16% of weekly flights between Seattle and London have experienced delays in the past year, with the average delay time being 123 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 Sunday 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 past year, Virgin Atlantic have had the lowest number of delays on this route, with just 6% of flights being delayed.
What’s the top stopover airport for flights from Seattle to London Heathrow Airport?
Share of one-stop return flights from Seattle to London Heathrow Airport chosen by Cheapflights users in the past 12 months, using the same stopover each way.
Reykjavik (KEF) – chosen by Cheapflights users on 67% of one-stop itineraries from Seattle to London Heathrow Airport on Cheapflights.
What’s the cheapest stopover airport for flights from Seattle to London Heathrow Airport?
Average return fare for one-stop flights from Seattle to London Heathrow Airport, chosen by Cheapflights users in the past 12 months, with the same stopover each way.
Dublin (DUB) is the most affordable one-stop option, with an average return flight price of £439.
What’s the fastest stopover option from Seattle to London Heathrow Airport?
Shortest average travel time for one-stop one-way flights from Seattle to London Heathrow Airport, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by stopover airport.
Flights via Dublin (DUB) have the shortest average one-way travel time for one-stop routes: 13h 50m.
Which airport typically offers the quickest stopover for flights from Seattle to London Heathrow Airport?
Average stopover duration for one-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 Dublin (DUB) offer the fastest connection on this route, with an average stopover time of 2h 21m.
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 30 December 2025.
Read through reviews of airlines operating flights from Seattle to London Heathrow Airport, such as Virgin Atlantic and British Airways. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
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!
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!
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?
If you book a flight to London Heathrow from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 11 flights from Seattle/Tacoma Intl to London Heathrow per day from 2 different airlines.
How long is the flight from Seattle to London Heathrow Airport?
For as low as £456, Icelandair can have you in London Heathrow Airport from Seattle in 9h 30m. The distance from Seattle to 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?
Cheapflights users have booked flights from Seattle to London Heathrow Airport round-trip from £351. Another airline that can offer you cheap pricing is Virgin Atlantic. You may be able to fly from Seattle to London Heathrow Airport for 40% less than the average price by searching for these airlines.
What are the cheapest airlines to fly from Seattle to London Heathrow Airport one-way?
One-way options have recently been found by users for as low as £160 on Icelandair. Other airlines that offer cheap prices include Virgin Atlantic from £290 and British Airways from £291 one-way.
What are the most reliable airlines from Seattle to London Heathrow Airport?
Consider Air France (81%), KLM (81%) or Delta (80%) when booking your flight. These represent the most reliable airlines when flying from Seattle to London Heathrow Airport.
What are the cheapest flights from Seattle to London Heathrow Airport?
While on average a flight from Seattle to London Heathrow Airport is generally £627, our data shows the cheapest flight currently is £283. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £369 for that flight.
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 £369). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of £585). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
Explore flights to Heathrow departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on 30 December 2025.
Discover the top 2 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 858,174 searches. Data last updated 30 December 2025.
Find the best flight deals on Cheapflights, where travellers 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?
Cheapflights helps you search for flights from Seattle to Heathrow via 900+ travel sites so you don’t have to. After performing a flight search, users can also filter their flight selection by filtering for price, number of stops, airlines, and so on.
Why should you use Cheapflights to find cheap flight tickets from Seattle to Heathrow?
Cheapflights helps you find that perfect flight to Heathrow from Seattle by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!
Can Cheapflights find flights from Seattle to Heathrow with no change fees?
Yes! Cheapflights helps users easily find flights from Seattle to Heathrow with no change fees.
Can Cheapflights notify me if prices for flights from Seattle to Heathrow become cheaper?
Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!
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