What’s the fastest layover option from Seattle to London Heathrow Airport?

Flights via Dublin (DUB) have the shortest average one-way travel time for 1-stop routes: 12h 10m.

What’s the top layover airport for flights from Seattle to London Heathrow Airport?

Reykjavik (KEF) – chosen by Cheapflights users on 83% of 1-stop itineraries from Seattle to London Heathrow Airport on Cheapflights.

Which airport typically offers the quickest layover for flights from Seattle to London Heathrow Airport?

Flights via Reykjavik (KEF) offer the fastest connection on this route, with an average layover time of 1h 29m.

What’s the cheapest layover airport for flights from Seattle to London Heathrow Airport?

Reykjavik (KEF) is the most affordable 1-stop option, with an average round-trip price of $530.

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

For as low as $517, Delta can have you in London Heathrow Airport from Seattle in 9h 30m. The distance between Seattle and London Heathrow Airport is about 4783 mi. All flights are typically nonstop.

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 Lufthansa. Our recent data shows that you can find tickets from as low as $378 on this airline. Additional options worth looking into are Icelandair and Aer Lingus, starting at $484 and $523 round-trip. Lufthansa is currently priced 52% below the average price you’ll pay for this route.

Weekly flight availability from Seattle to London Heathrow Airport

The most flights from SEA to LHR are scheduled on a Monday (21 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (15 on average).

In terms of precipitation, rainfall in London Heathrow Airport ranges from 1.6 - 2.8 inches per month. January is typically the wettest month, when rainfall can reach 2.8 in. July is typically the driest time to visit London Heathrow Airport when rainfall is around 1.6 in.

If weather is an important factor for your trip to London Heathrow Airport, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 62.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 39.2 F).

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 $2,215, our data indicates the cheapest price to be $326. The most popular route (Seattle/Tacoma Intl - London Heathrow), is priced around $471.

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 Aeromexico (90%), KLM (83%) or Air France (83%) as they are the most reliable in getting you off to your destination on time.

What are the most popular airlines that fly from Seattle to London Heathrow Airport?

Before booking your flight from Seattle to London Heathrow Airport check out the most popular airlines for this route: American Airlines, Air Canada or Air France.

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 15 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.

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.

$265+ Cheap Flights from Seattle to London Heathrow Airport

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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

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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London Heathrow are usually found in March or April, booked 32 days in advance, depart on a Tuesday or Wednesday and return on a Wednesday

Cheap flight deals from Seattle to Heathrow

Round-trip from	$508 (Mytrip)
One-way from	$265 (Kiwi.com)
Popular in	June
Cheapest in	March
Average price	$702
Good round-trip deal	$654 or less
Good one-way deal	$417 or less

From Seattle/Tacoma Intl to London Heathrow

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One-way flight from Seattle/Tacoma Intl to London Heathrow

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Highest demand for flights based on searches. 16% potential increase in price ($163 potential increase over avg. RT price).

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Cheapest flight prices on average. 3% potential price decrease ($27 potential savings vs. average RT price).

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Average for round-trip flights in September 2025

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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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Find 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 September 17, 2025.

Mon 9/225:35 pmSEA - LHR

Nonstop9h 45mVirgin Atlantic

Tue 10/75:35 pmLHR - SEA

1 stop25h 40mVirgin Atlantic

Deal found 9/15

$508

Wed 11/124:48 pmSEA - LHR

Nonstop9h 42mDelta

Wed 11/196:20 amLHR - SEA

1 stop15h 00mDelta

Deal found 9/16

$509

Wed 11/124:48 pmSEA - LHR

Nonstop9h 42mAir France

Thu 11/206:20 amLHR - SEA

1 stop13h 05mAir France

Deal found 9/15

$510

Tue 10/148:25 pmSEA - LHR

Nonstop9h 50mDelta

Thu 10/236:30 amLHR - SEA

1 stop17h 35mDelta

Deal found 9/15

$511

Wed 10/11:30 pmSEA - LHR

Nonstop9h 20mBritish Airways

Tue 10/149:25 amLHR - SEA

Nonstop9h 45mBritish Airways

Deal found 9/15

$512

Mon 10/63:45 pmSEA - LHR

1 stop12h 10mIcelandair

Fri 10/101:05 pmLHR - SEA

1 stop15h 35mIcelandair

Deal found 9/16

$513

Mon 9/222:25 pmSEA - LHR

1 stop18h 50mDelta

Tue 10/76:15 amLHR - SEA

1 stop19h 25mDelta

Deal found 9/15

$514

Thu 11/62:35 pmSEA - LHR

1 stop12h 15mIcelandair

Tue 11/1812:15 pmLHR - SEA

1 stop12h 45mIcelandair

Deal found 9/15

$515

Mon 10/2712:41 pmSEA - LHR

2 stops37h 59mUnited Airlines

Fri 11/72:30 pmLHR - SEA

1 stop27h 01mUnited Airlines

Deal found 9/17

$516

Tue 11/47:20 pmSEA - LHR

Nonstop9h 30mDelta

Wed 11/1912:20 pmLHR - SEA

Nonstop10h 28mDelta

Deal found 9/15

$517

Wed 10/295:45 pmSEA - LHR

Nonstop9h 45mAir France

Tue 11/1112:20 pmLHR - SEA

Nonstop10h 28mAir France

Deal found 9/16

$518

Sat 9/274:35 pmSEA - LHR

1 stop35h 00mUnited Airlines

Fri 10/106:55 amLHR - SEA

1 stop18h 04mUnited Airlines

Deal found 9/17

$519

Best flights from Seattle to Heathrow
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 September 17, 2025.

Wed 11/124:48 pmSEA - LHR

Nonstop9h 42mDelta

Wed 11/196:20 amLHR - SEA

1 stop15h 00mDelta

Deal found 9/16

$509

Mon 3/97:50 pmSEA - LHR

Nonstop9h 30mBritish Airways

Thu 3/262:55 pmLHR - SEA

Nonstop10h 00mBritish Airways

Deal found 9/15

$517

Tue 11/185:50 amSEA - LHR

1 stop22h 00mUnited Airlines

Thu 11/276:50 amLHR - SEA

2 stops22h 04mUnited Airlines

Deal found 9/16

$517

Tue 3/32:35 pmSEA - LHR

1 stop20h 55mIcelandair

Mon 3/309:25 pmLHR - SEA

1 stop31h 45mIcelandair

Deal found 9/15

$524

Mon 10/275:45 pmSEA - LHR

Nonstop9h 45mDelta

Tue 11/116:20 amLHR - SEA

1 stop13h 05mDelta

Deal found 9/15

$510

Wed 3/46:50 pmSEA - LHR

Nonstop9h 30mBritish Airways

Thu 3/262:55 pmLHR - SEA

Nonstop10h 00mBritish Airways

Deal found 9/15

$517

Tue 10/71:00 pmSEA - LHR

3 stops33h 30mUnited Airlines

Wed 10/156:30 amLHR - SEA

2 stops20h 06mUnited Airlines

Deal found 9/17

$530

Mon 10/65:35 pmSEA - LHR

Nonstop9h 45mDelta

Wed 10/226:15 amLHR - SEA

1 stop13h 00mDelta

Deal found 9/17

$510

Tue 10/287:50 pmSEA - LHR

Nonstop9h 30mBritish Airways

Tue 11/119:25 amLHR - SEA

Nonstop10h 05mBritish Airways

Deal found 9/17

$518

Sun 11/29:25 amSEA - LHR

1 stop13h 40mDelta

Tue 11/116:20 amLHR - SEA

1 stop13h 05mDelta

Deal found 9/16

$515

Tue 10/78:25 pmSEA - LHR

Nonstop9h 50mDelta

Tue 10/215:25 pmLHR - SEA

Nonstop10h 25mDelta

Deal found 9/17

$518

Last-minute flights from Seattle to Heathrow
Discover last-minute flight deals from Seattle to Heathrow. Data last updated September 17, 2025 and is based on user searches.

Mon 9/225:35 pmSEA - LHR

Nonstop9h 45mVirgin Atlantic

Tue 10/75:35 pmLHR - SEA

1 stop25h 40mVirgin Atlantic

Deal found 9/15

$508

Mon 9/228:25 pmSEA - LHR

Nonstop9h 50mDelta

Thu 10/26:15 amLHR - SEA

1 stop19h 25mDelta

Deal found 9/15

$509

Mon 9/222:25 pmSEA - LHR

1 stop18h 50mDelta

Tue 10/76:15 amLHR - SEA

1 stop19h 25mDelta

Deal found 9/15

$514

Mon 9/225:35 pmSEA - LHR

Nonstop9h 45mDelta

Fri 10/36:00 pmLHR - SEA

Nonstop10h 25mDelta

Deal found 9/15

$517

Sat 9/274:35 pmSEA - LHR

1 stop35h 00mUnited Airlines

Fri 10/106:55 amLHR - SEA

1 stop18h 04mUnited Airlines

Deal found 9/17

$519

Sun 9/286:00 amSEA - LHR

1 stop23h 10mDelta

Tue 10/148:40 amLHR - SEA

1 stop15h 25mDelta

Deal found 9/16

$515

Wed 10/18:25 pmSEA - LHR

Nonstop9h 50mDelta

Fri 10/106:15 amLHR - SEA

1 stop13h 00mDelta

Deal found 9/15

$510

Wed 10/11:30 pmSEA - LHR

Nonstop9h 20mBritish Airways

Tue 10/149:25 amLHR - SEA

Nonstop9h 45mBritish Airways

Deal found 9/15

$512

Mon 10/63:45 pmSEA - LHR

1 stop12h 10mIcelandair

Fri 10/101:05 pmLHR - SEA

1 stop15h 35mIcelandair

Deal found 9/16

$513

Tue 10/148:25 pmSEA - LHR

Nonstop9h 50mDelta

Thu 10/236:30 amLHR - SEA

1 stop17h 35mDelta

Deal found 9/15

$511

Mon 10/2712:41 pmSEA - LHR

2 stops37h 59mUnited Airlines

Fri 11/72:30 pmLHR - SEA

1 stop27h 01mUnited Airlines

Deal found 9/17

$516

Wed 10/2910:05 amSEA - LHR

2 stops17h 05mAir Canada

Tue 11/112:30 pmLHR - SEA

1 stop27h 01mAir Canada

Deal found 9/16

$518

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 September 17, 2025.

Sat 10/49:39 pmSEA - LHR

2 stops40h 21mMultiple Airlines

Deal found 9/14

$265

Sun 2/153:10 pmSEA - LHR

1 stop13h 40mWestJet

Deal found 9/15

$268

Fri 11/143:10 pmSEA - LHR

1 stop13h 40mWestJet

Deal found 9/15

$269

Thu 11/139:08 amSEA - LHR

2 stops24h 22mMultiple Airlines

Deal found 9/16

$270

Mon 12/111:10 pmSEA - LHR

3 stops29h 40mMultiple Airlines

Deal found 9/15

$272

Mon 10/202:05 pmSEA - LHR

2 stops22h 15mMultiple Airlines

Deal found 9/15

$274

Thu 11/133:10 pmSEA - LHR

1 stop13h 40mWestJet

Deal found 9/15

$277

Sat 11/811:55 amSEA - LHR

2 stops16h 55mWestJet

Deal found 9/15

$278

Mon 10/61:47 pmSEA - LHR

3 stops43h 58mMultiple Airlines

Deal found 9/15

$279

Sun 11/23:10 pmSEA - LHR

1 stop13h 40mWestJet

Deal found 9/16

$280

Sat 11/1511:55 amSEA - LHR

2 stops16h 55mWestJet

Deal found 9/16

$281

Cheapflights Fare Finder

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

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 11/12

4:48 pm-10:30 am

Nonstop9h 42m

London Heathrow

Wed 11/19

6:20 am-1:20 pm

1 stop15h 00m

$509

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 10/27

5:45 pm-10:30 am

Nonstop9h 45m

London Heathrow

Tue 11/11

6:20 am-11:25 am

1 stop13h 05m

$510

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 10/6

5:35 pm-11:20 am

Nonstop9h 45m

London Heathrow

Wed 10/22

6:15 am-11:15 am

1 stop13h 00m

$510

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 11/2

9:25 am-7:05 am

1 stop13h 40m

London Heathrow

Tue 11/11

6:20 am-11:25 am

1 stop13h 05m

$515

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 3/9

7:50 pm-12:20 pm

Nonstop9h 30m

London Heathrow

Thu 3/26

2:55 pm-5:55 pm

Nonstop10h 00m

$517

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 11/18

5:50 am-11:50 am

1 stop22h 00m

London Heathrow

Thu 11/27

6:50 am-8:54 pm

2 stops22h 04m

$517

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 3/4

6:50 pm-12:20 pm

Nonstop9h 30m

London Heathrow

Thu 3/26

2:55 pm-5:55 pm

Nonstop10h 00m

$517

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 10/28

7:50 pm-12:20 pm

Nonstop9h 30m

London Heathrow

Tue 11/11

9:25 am-11:30 am

Nonstop10h 05m

$518

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 10/7

8:25 pm-2:15 pm

Nonstop9h 50m

London Heathrow

Tue 10/21

5:25 pm-7:50 pm

Nonstop10h 25m

$518

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 3/3

2:35 pm-7:30 pm

1 stop20h 55m

London Heathrow

Mon 3/30

9:25 pm-9:10 pm

1 stop31h 45m

$524

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/16

Showing 1-10 of 22 results

The best insider tips for Seattle to London Heathrow Airport flights

Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to London Heathrow Airport trip

Airports

SEA

Use SEA Spot Saver to book security screening appointments in advance, reducing wait times without needing TSA PreCheck or CLEAR.

LHR

Take the Heathrow Express for the fastest route to central London, reaching Paddington Station quickly and conveniently.

Our travel experts

Ramsey Qubein

Expert on LHR

Brandon Schultz

Expert on SEA

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

Prices

Airlines

How far ahead should I book a flight from Seattle to London Heathrow Airport?

Booking 32 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, November is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of $661). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of $1,097). 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?

When flying from Seattle to London Heathrow Airport, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 15% versus a flight in the morning.

What is the cheapest day to fly from Seattle to London Heathrow Airport?

Travelers seeking maximum savings on their Seattle to London Heathrow Airport flight should consider departing on Monday mornings when fares are most often at their lowest. Thursday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

Reviews of airlines servicing Heathrow

Read reviews from past customers who have flown Delta, Virgin Atlantic, and Icelandair 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

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Delta

8.0

Very good

7,961 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Virgin Atlantic

7.4

Good

664 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Icelandair

7.0

Good

545 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Iberia

7.0

Good

2,925 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

British Airways

6.7

Okay

7,367 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Related info for your journey

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 15 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 $517, Delta can have you in London Heathrow Airport from Seattle in 9h 30m. The distance between Seattle and London Heathrow Airport is about 4783 mi. All flights are typically nonstop.
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 Lufthansa. Our recent data shows that you can find tickets from as low as $378 on this airline. Additional options worth looking into are Icelandair and Aer Lingus, starting at $484 and $523 round-trip. Lufthansa is currently priced 52% below the average price you’ll pay for this route.
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 Aeromexico (90%), KLM (83%) or Air France (83%) 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 $2,215, our data indicates the cheapest price to be $326. The most popular route (Seattle/Tacoma Intl - London Heathrow), is priced around $471.
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, November is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of $661). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of $1,097). 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.

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Top 10 airlines flying from Seattle to Heathrow

Airline	Cheapest	Average	Flexibility	On-time
Lufthansa	Cheapest$378	Average$865	FlexibilityNo cancel fee	On-time76%
Icelandair	Cheapest$484	Average$641	FlexibilityNo cancel fee	On-time76%
Aer Lingus	Cheapest$523	Average$733	FlexibilityNo cancel fee	On-timeN/A
Scandinavian Airlines	Cheapest$532	Average$741	FlexibilityNo cancel fee	On-time77%
Air France	Cheapest$532	Average$804	FlexibilityNo cancel fee	On-time77%
United Airlines	Cheapest$547	Average$825	FlexibilityNo cancel fee	On-time69%
Finnair	Cheapest$556	Average$706	FlexibilityNo cancel fee	On-time76%
British Airways	Cheapest$556	Average$804	FlexibilityNo cancel fee	On-time70%
Delta	Cheapest$563	Average$846	FlexibilityNo cancel fee	On-timeN/A
American Airlines	Cheapest$569	Average$865	FlexibilityNo cancel fee	On-time71%

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$265+ 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 10/4. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Seattle to Heathrow with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London Heathrow are usually found in March or April, booked 32 days in advance, depart on a Tuesday or Wednesday and return on a Wednesday

Cheap flight deals from Seattle to Heathrow

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Good round-trip deal

Good one-way deal

Find flight deals from Seattle to Heathrow

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 September 17, 2025.

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 September 17, 2025.

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Use the filters below to find and compare flights from Seattle to London Heathrow Airport that are best for you.

The best insider tips for Seattle to London Heathrow Airport flights

Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to London Heathrow Airport trip

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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.

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?

What is the cheapest month to book a flight from Seattle to London Heathrow Airport?

What is the cheapest time of day to fly from SEA to LHR?

What is the cheapest day to fly from Seattle to London Heathrow Airport?

Weekly flight availability from Seattle to London Heathrow Airport

What’s the top layover airport for flights from Seattle to London Heathrow Airport?

What’s the fastest layover option from Seattle to London Heathrow Airport?

What’s the fastest layover option from Seattle to London Heathrow Airport?

Which airport typically offers the quickest layover for flights from Seattle to London Heathrow Airport?

Reviews of airlines servicing Heathrow

Read reviews from past customers who have flown Delta, Virgin Atlantic, and Icelandair 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.

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?

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

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

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

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

Can I find deals for flights from Seattle to Heathrow that include hotel bookings?

How can I find direct flights from Seattle to Heathrow?

Can I find deals for business class flights from Seattle to Heathrow?

What is the cheapest month to book a flight from Seattle to London Heathrow Airport?

Traveling to a place near London Heathrow Airport?

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Alternative routes for Seattle to Heathrow

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Top 10 airlines flying from Seattle to Heathrow

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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 September 17, 2025.