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 $535 on this airline. Additional options worth looking into are United Airlines and Icelandair, starting at $536 and $538 round-trip. Aer Lingus is currently priced 33% 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 ($211), JetBlue ($238), and WestJet ($282).

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 $2,714, our data indicates the cheapest price to be $307. 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 Scandinavian Airlines (92%), KLM (91%) or Air France (91%) 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 is the cheapest day to fly round-trip from Seattle to London Heathrow Airport?

Departing on a Monday is a good option for securing a great price. You can expect to save up to 16% when planning your travel around this day of the week.

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

To save up to 44% on this flight, we recommend booking at least 51 days prior to travel. The price may fluctuate and will likely increase closer to your departure date. Users on Cheapflights have found tickets from Seattle to London Heathrow Airport from $805 1-2 weeks out and tickets from $958 for flights departing within the next 72 hours.

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

The best pricing can be found in the month of October. Prices to London Heathrow Airport from Seattle average $771. You can even find prices in October for less than $771, as users have found deals to London Heathrow Airport from as low as $544. The month of June appears to be one of the more expensive times to travel to London Heathrow Airport from Seattle. Flying in the targeted month can save you up to 30%.

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 21 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.

$211+ Flights from Seattle to London Heathrow Airport

Home Search by date Vacation packages Hotels Flight deals Car rental Travel tips & news

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 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	$535 (CheapOair)
One-way from	$211 (SmartFares)
Popular in	June
Cheapest in	March
Average price	$995
Good round-trip deal	$611 or less
Good one-way deal	$426 or less

From Seattle/Tacoma Intl to London Heathrow

Search Deals

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

Search Deals

Highest demand for flights based on searches. 17% potential increase in price ($166 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 3% potential price decrease ($26 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in July 2025

Search Deals

Price to beat on a round-trip flight from Seattle/Tacoma Intl to London Heathrow.

Search Deals

Price to beat on a one-way flight from Seattle/Tacoma Intl to London Heathrow.

Search Deals

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 July 18, 2025.

Thu 8/141:30 pmSEA - LHR

Nonstop9h 20mAmerican Airlines

Thu 8/219:30 amLHR - SEA

1 stop14h 30mAmerican Airlines

Deal found 7/17

$535

Sun 8/317:35 pmSEA - LHR

1 stop12h 20mAer Lingus

Wed 9/1012:00 pmLHR - SEA

1 stop13h 50mAer Lingus

Deal found 7/17

$537

Tue 8/263:09 pmSEA - LHR

1 stop13h 06mBritish Airways

Mon 9/88:35 pmLHR - SEA

2 stops33h 29mBritish Airways

Deal found 7/17

$539

Sat 8/97:00 pmSEA - LHR

1 stop32h 55mIcelandair

Sat 8/169:25 pmLHR - SEA

1 stop22h 00mIcelandair

Deal found 7/14

$541

Sun 8/101:55 pmSEA - LHR

1 stop12h 50mKLM

Fri 9/196:30 amLHR - SEA

1 stop13h 15mKLM

Deal found 7/15

$542

Wed 8/277:20 amSEA - LHR

1 stop15h 10mUnited Airlines

Mon 9/89:30 amLHR - SEA

1 stop34h 25mUnited Airlines

Deal found 7/16

$543

Wed 8/277:20 amSEA - LHR

1 stop15h 10mMultiple Airlines

Sat 9/68:45 amLHR - SEA

1 stop14h 05mMultiple Airlines

Deal found 7/16

$548

Mon 8/48:25 pmSEA - LHR

Nonstop9h 50mDelta

Wed 8/139:00 amLHR - SEA

1 stop16h 35mDelta

Deal found 7/17

$557

Wed 9/1010:00 amSEA - LHR

2 stops15h 35mLufthansa

Thu 9/252:10 pmLHR - SEA

1 stop16h 06mLufthansa

Deal found 7/17

$561

Fri 7/258:25 pmSEA - LHR

Nonstop9h 50mAir France

Wed 8/275:25 pmLHR - SEA

Nonstop10h 20mAir France

Deal found 7/14

$568

Mon 8/254:25 pmSEA - LHR

2 stops31h 50mSWISS

Thu 9/48:40 amLHR - SEA

2 stops22h 19mSWISS

Deal found 7/16

$569

Wed 8/1311:42 amSEA - LHR

1 stop15h 08mIberia

Sun 8/249:15 amLHR - SEA

1 stop18h 49mIberia

Deal found 7/15

$573

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 July 18, 2025.

Wed 9/177:35 pmSEA - LHR

1 stop12h 20mAer Lingus

Wed 10/19:50 amLHR - SEA

1 stop16h 00mAer Lingus

Deal found 7/17

$535

Tue 7/292:55 pmSEA - LHR

1 stop14h 25mUnited Airlines

Wed 8/138:30 amLHR - SEA

1 stop15h 50mUnited Airlines

Deal found 7/17

$536

Thu 11/202:35 pmSEA - LHR

1 stop20h 55mIcelandair

Thu 11/2712:15 pmLHR - SEA

1 stop12h 45mIcelandair

Deal found 7/17

$538

Tue 8/263:09 pmSEA - LHR

1 stop13h 06mBritish Airways

Mon 9/88:35 pmLHR - SEA

2 stops33h 29mBritish Airways

Deal found 7/17

$539

Thu 8/141:32 pmSEA - LHR

1 stop13h 33mAmerican Airlines

Thu 8/2110:20 amLHR - SEA

1 stop13h 40mAmerican Airlines

Deal found 7/17

$540

Mon 9/84:25 pmSEA - LHR

1 stop35h 00mSWISS

Mon 9/155:10 pmLHR - SEA

2 stops33h 26mSWISS

Deal found 7/17

$546

Wed 8/277:20 amSEA - LHR

1 stop15h 10mMultiple Airlines

Sat 9/68:45 amLHR - SEA

1 stop14h 05mMultiple Airlines

Deal found 7/16

$548

Fri 9/195:35 pmSEA - LHR

Nonstop9h 45mVirgin Atlantic

Tue 9/239:55 amLHR - SEA

1 stop18h 20mVirgin Atlantic

Deal found 7/16

$550

Mon 8/48:25 pmSEA - LHR

Nonstop9h 50mDelta

Wed 8/1311:30 amLHR - SEA

1 stop14h 05mDelta

Deal found 7/16

$557

Thu 8/2112:05 pmSEA - LHR

2 stops34h 25mAir Canada

Tue 8/269:30 amLHR - SEA

2 stops44h 46mAir Canada

Deal found 7/17

$572

Sun 9/710:00 amSEA - LHR

2 stops15h 35mLufthansa

Tue 9/166:30 amLHR - SEA

1 stop13h 25mLufthansa

Deal found 7/17

$579

Sat 8/165:25 amSEA - LHR

1 stop17h 00mIberia

Thu 8/282:25 pmLHR - SEA

1 stop17h 16mIberia

Deal found 7/17

$583

Last-minute flights from Seattle to Heathrow
Discover last-minute flight deals from Seattle to Heathrow. Data last updated July 18, 2025 and is based on user searches.

Wed 7/238:25 pmSEA - LHR

Nonstop9h 50mMultiple Airlines

Mon 8/48:40 amLHR - SEA

1 stop15h 15mMultiple Airlines

Deal found 7/14

$620

Fri 7/258:25 pmSEA - LHR

Nonstop9h 50mAir France

Wed 8/275:25 pmLHR - SEA

Nonstop10h 20mAir France

Deal found 7/14

$568

Sat 7/268:20 pmSEA - LHR

Nonstop9h 20mBritish Airways

Thu 8/289:50 amLHR - SEA

Nonstop9h 45mBritish Airways

Deal found 7/15

$561

Sun 7/277:20 amSEA - LHR

1 stop15h 10mUnited Airlines

Wed 8/132:50 pmLHR - SEA

1 stop14h 33mUnited Airlines

Deal found 7/17

$541

Sun 7/275:35 pmSEA - LHR

Nonstop9h 45mDelta

Wed 8/136:15 amLHR - SEA

1 stop19h 20mDelta

Deal found 7/17

$557

Mon 8/48:25 pmSEA - LHR

Nonstop9h 50mDelta

Wed 8/139:00 amLHR - SEA

1 stop16h 35mDelta

Deal found 7/17

$557

Sat 8/97:00 pmSEA - LHR

1 stop32h 55mIcelandair

Sat 8/169:25 pmLHR - SEA

1 stop22h 00mIcelandair

Deal found 7/14

$541

Sun 8/101:55 pmSEA - LHR

1 stop12h 50mKLM

Fri 9/196:30 amLHR - SEA

1 stop13h 15mKLM

Deal found 7/15

$542

Wed 8/1311:42 amSEA - LHR

1 stop15h 08mIberia

Sun 8/249:15 amLHR - SEA

1 stop18h 49mIberia

Deal found 7/15

$573

Thu 8/141:30 pmSEA - LHR

Nonstop9h 20mAmerican Airlines

Thu 8/219:30 amLHR - SEA

1 stop14h 30mAmerican Airlines

Deal found 7/17

$535

Mon 8/185:30 amSEA - LHR

2 stops41h 00mAir Canada

Thu 9/49:30 amLHR - SEA

1 stop18h 01mAir Canada

Deal found 7/17

$576

Mon 8/254:25 pmSEA - LHR

2 stops31h 50mSWISS

Thu 9/48:40 amLHR - SEA

2 stops22h 19mSWISS

Deal found 7/16

$569

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 July 18, 2025.

Tue 10/143:45 pmSEA - LHR

1 stop12h 10mIcelandair

Deal found 7/17

$211

Wed 9/1711:30 amSEA - LHR

1 stop35h 00mJetBlue

Deal found 7/17

$238

Tue 10/143:45 pmSEA - LHR

2 stops21h 35mMultiple Airlines

Deal found 7/16

$268

Fri 10/241:50 pmSEA - LHR

1 stop14h 15mWestJet

Deal found 7/16

$282

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

Thu 8/14

1:30 pm-6:50 am

Nonstop9h 20m

London Heathrow

Thu 8/21

9:30 am-4:00 pm

1 stop14h 30m

$535

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 8/31

7:35 pm-3:55 pm

1 stop12h 20m

London Heathrow

Wed 9/10

12:00 pm-5:50 pm

1 stop13h 50m

$537

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 8/26

3:09 pm-12:15 pm

1 stop13h 06m

London Heathrow

Mon 9/8

8:35 pm-10:04 pm

2 stops33h 29m

$539

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 8/9

7:00 pm-11:55 am

1 stop32h 55m

London Heathrow

Sat 8/16

9:25 pm-11:25 am

1 stop22h 00m

$541

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 8/10

1:55 pm-10:45 am

1 stop12h 50m

London Heathrow

Thu 8/21

6:30 am-11:35 am

1 stop13h 05m

$542

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 8/27

7:20 am-6:30 am

1 stop15h 10m

London Heathrow

Mon 9/8

9:30 am-11:55 am

1 stop34h 25m

$543

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 10/1

5:30 am-6:30 am

2 stops17h 00m

London Heathrow

Tue 10/14

2:10 pm-6:36 pm

1 stop12h 26m

$547

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 8/27

7:20 am-6:30 am

1 stop15h 10m

London Heathrow

Sat 9/6

8:45 am-2:50 pm

1 stop14h 05m

$548

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 9/10

10:00 am-9:35 am

2 stops15h 35m

London Heathrow

Thu 9/25

2:10 pm-10:16 pm

1 stop16h 06m

$561

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 7/29

1:30 pm-9:50 am

1 stop12h 20m

London Heathrow

Tue 8/12

6:30 am-11:35 am

1 stop13h 05m

$563

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/17

Showing 1-10 of 16 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

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 $1,095). 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 14% 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.

Weekly flight availability from Seattle to London Heathrow Airport

The most flights from SEA to LHR are scheduled on a Monday (22 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (16 on average).

Reviews of airlines servicing Heathrow

Read reviews from past customers who have flown Delta, SWISS, and United Airlines 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

7,959 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

7,959 reviews

Delta

8.0

Very good

7,959 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!

SWISS

7.5

Good

1,661 reviews

Delta

8.0

Very good

7,959 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!

United Airlines

7.4

Good

8,864 reviews

Delta

8.0

Very good

7,959 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

655 reviews

Delta

8.0

Very good

7,959 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!

JetBlue

7.3

Good

2,909 reviews

Delta

8.0

Very good

7,959 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 21 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.
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 $535 on this airline. Additional options worth looking into are United Airlines and Icelandair, starting at $536 and $538 round-trip. Aer Lingus is currently priced 33% 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 ($211), JetBlue ($238), and WestJet ($282).
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 Scandinavian Airlines (92%), KLM (91%) or Air France (91%) 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 $2,714, our data indicates the cheapest price to be $307. 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 $1,095). 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

Hounslow

Hayes

Thornton Heath

Harrow

Canterbury

Dover

Stratford-upon-Avon

Gatwick

Orpington

Watford

Northampton

Croydon

Borehamwood

Broadway

Aylesbury

Chelmsford

Folkestone

Chichester

Southend-on-Sea

Swindon

Browse thousands of different options on Cheapflights for your next trip

Alternative routes for Seattle to Heathrow

Seattle to Gatwick flights

Seattle to London City flights

Portland to Heathrow flights

Seattle to Luton flights

Seattle to Stansted flights

Portland to Gatwick flights

Portland to London City flights

Spokane to Heathrow flights

Portland to Stansted flights

Portland to Luton flights

Spokane to Gatwick flights

Spokane to London City flights

Seattle to Southend flights

Pasco to Heathrow flights

Bellingham to Heathrow flights

Walla Walla to Heathrow flights

Bellingham to Gatwick flights

Portland to Southend flights

Other flights to Heathrow

Boston to Heathrow flights

John F Kennedy Intl to Heathrow flights

Newark to Heathrow flights

Los Angeles to Heathrow flights

Portland to Heathrow flights

Dulles Intl to Heathrow flights

London Heathrow Airport to Manchester flights

London Heathrow Airport to Aberdeen flights

London Heathrow Airport to Belfast City Airport flights

London Heathrow Airport to Inverness flights

London Heathrow Airport to Newcastle upon Tyne flights

London Heathrow Airport to Manchester flights

London Heathrow Airport to Paris Orly Airport flights

London Heathrow Airport to Edinburgh flights

London Heathrow Airport to Toulouse flights

London Heathrow Airport to Glasgow Intl Airport flights

London Heathrow Airport to Milan Linate Airport flights

London Heathrow Airport to Belgrade flights

London Heathrow Airport to Paris Charles de Gaulle Airport flights

London Heathrow Airport to Barcelona-El Prat Airport flights

London Heathrow Airport to Amsterdam flights

London Heathrow Airport to Hamburg flights

London Heathrow Airport to Brussels Bruxelles-National Airport flights

London Heathrow Airport to Duesseldorf Intl Airport flights

Top 10 airlines flying from Seattle to Heathrow

Airline	Cheapest	Average	Flexibility	On-time
Lufthansa	Cheapest$378	Average$824	FlexibilityNo cancel fee	On-time76%
Icelandair	Cheapest$505	Average$664	FlexibilityNo cancel fee	On-time76%
Scandinavian Airlines	Cheapest$532	Average$741	FlexibilityNo cancel fee	On-time77%
United Airlines	Cheapest$547	Average$825	FlexibilityNo cancel fee	On-time69%
Finnair	Cheapest$556	Average$728	FlexibilityNo cancel fee	On-time76%
Iberia	Cheapest$579	Average$728	FlexibilityNo cancel fee	On-time77%
Air France	Cheapest$583	Average$863	FlexibilityNo cancel fee	On-time77%
Aer Lingus	Cheapest$583	Average$802	FlexibilityNo cancel fee	On-timeN/A
British Airways	Cheapest$596	Average$837	FlexibilityNo cancel fee	On-time70%
KLM	Cheapest$597	Average$810	FlexibilityNo cancel fee	On-time75%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.

$211+ 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 10/14. 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 July 18, 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 July 18, 2025.

Cheapflights Fare Finder

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

Airports

SEA

LHR

Our travel experts

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?

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Heathrow. Price data was last updated on July 11, 2025.

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?

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 July 18, 2025.

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

Use this chart to determine the cheapest time to fly round-trip from Seattle to Heathrow. Price data was last updated on December 16, 2024.

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 July 18, 2025.

Reviews of airlines servicing Heathrow

Read reviews from past customers who have flown Delta, SWISS, and United Airlines 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?

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

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

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?

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Seattle to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.

Top 10 airlines flying from Seattle to Heathrow

100% Free

Book with Flexibility

Travel Smart

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 July 18, 2025.