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Cheap flights from Seattle to London Heathrow Airport from £228

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 4/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
9 Feb — 16 Feb1
1 adult

The best prices from Seattle/Tacoma Intl to London Heathrow are usually found in November or February, booked 44 days in advance, depart on a Monday or Sunday and return on a Tuesday

Cheap 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 4 February 2025.

Round-trip from

£487

One-way from

£228

Popular in

June

Cheapest in

November

Average price

£571

Good round-trip deal

£563 or less

Good one-way deal

£371 or less
Icelandair
  • Icelandair
  • 3/3-19/3
  • 2 total stops
  • 49h 15m total
  • Seattle to London
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WestJet
  • WestJet
  • 4/3
  • 2 total stops
  • 17h 20m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 21% potential increase in price (£149 potential increase over avg. return price).
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Cheapest flight prices on average. 4% potential price decrease (£25 potential savings vs. average return price).
Search Deals
Average for round-trip flights in February 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 4 February 2025.

Mon 3/314:35SEA - LHR
1 stop20h 55mIcelandair
Wed 19/320:40LHR - SEA
1 stop28h 20mIcelandair
Deal found 3/2£487
Tue 11/314:35SEA - LHR
Nonstop9h 25mIberia
Wed 19/315:00LHR - SEA
Nonstop9h 55mIberia
Deal found 3/2£493
Tue 18/307:15SEA - LHR
1 stop16h 10mVirgin Atlantic
Tue 25/313:15LHR - SEA
Nonstop10h 00mVirgin Atlantic
Deal found 2/2£506
Mon 3/319:05SEA - LHR
1 stop31h 05mMultiple Airlines
Tue 18/306:30LHR - SEA
2 stops18h 55mMultiple Airlines
Deal found 3/2£510
Sun 9/319:05SEA - LHR
1 stop32h 05mLufthansa
Tue 18/306:30LHR - SEA
2 stops18h 55mLufthansa
Deal found 3/2£514
Mon 3/310:35SEA - LHR
2 stops14h 45mAir Canada
Wed 19/315:00LHR - SEA
2 stops30h 30mAir Canada
Deal found 3/2£523
Wed 5/320:00SEA - LHR
1 stop11h 35mAer Lingus
Wed 12/307:50LHR - SEA
1 stop18h 25mAer Lingus
Deal found 3/2£523
Tue 29/413:30SEA - LHR
Nonstop9h 20mFinnair
Wed 7/509:30LHR - SEA
1 stop14h 30mFinnair
Deal found 3/2£528
Tue 22/420:20SEA - LHR
Nonstop9h 20mBritish Airways
Wed 30/409:50LHR - SEA
Nonstop9h 45mBritish Airways
Deal found 3/2£537
Tue 29/410:35SEA - LHR
1 stop18h 45mUnited Airlines
Tue 6/506:30LHR - SEA
2 stops15h 43mUnited Airlines
Deal found 3/2£539
Thu 6/215:20SEA - LHR
1 stop30h 35mJetBlue
Thu 20/208:25LHR - SEA
1 stop22h 13mJetBlue
Deal found 3/2£544
Mon 3/317:45SEA - LHR
Nonstop9h 25mDelta
Tue 11/306:30LHR - SEA
1 stop13h 10mDelta
Deal found 3/2£547

Find flights from Seattle to Heathrow within your budget

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 4 February 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 3/3

14:35-19:30

1 stop20h 55m

London Heathrow

Wed 19/3

20:40-18:00

1 stop28h 20m

£487

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 11/3

14:35-07:00

Nonstop9h 25m

London Heathrow

Wed 19/3

15:00-17:55

Nonstop9h 55m

£493

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 18/3

07:15-06:25

1 stop16h 10m

London Heathrow

Tue 25/3

13:15-16:15

Nonstop10h 00m

£506

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 3/3

19:05-10:10

1 stop31h 05m

London Heathrow

Wed 19/3

06:30-18:25

2 stops18h 55m

£512

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 9/3

19:05-10:10

1 stop32h 05m

London Heathrow

Tue 18/3

06:30-18:25

2 stops18h 55m

£514

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 3/3

10:35-09:20

2 stops14h 45m

London Heathrow

Wed 19/3

15:00-14:30

2 stops30h 30m

£523

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 5/3

20:00-15:35

1 stop11h 35m

London Heathrow

Wed 12/3

07:50-19:15

1 stop18h 25m

£523

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 29/4

13:30-06:50

Nonstop9h 20m

London Heathrow

Wed 7/5

09:30-16:00

1 stop14h 30m

£528

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 22/4

20:20-13:40

Nonstop9h 20m

London Heathrow

Wed 30/4

09:50-11:35

Nonstop9h 45m

£537

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 29/4

15:05-13:20

1 stop14h 15m

London Heathrow

Tue 6/5

06:30-14:13

2 stops15h 43m

£539

Flights are sorted by cheapest return flights first.

Deals found on 3/2

Showing 1-10 of 29 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.

Travel insights for flights from Seattle to Heathrow

Get recent, data-driven insights about flights from Seattle to Heathrow including ideal travel times, pricing trends, and 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 31 January 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 44 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, January is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £112). Flying from Seattle to London Heathrow Airport in August is currently the most expensive (average of £162). 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 4 February 2025.

Unlike in the morning, when flights are generally more expensive, you can save up to 17% on flights from Seattle to London Heathrow Airport by exploring options for tickets at midday.

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 4 February 2025.

The most flights from SEA to LHR are scheduled on a Friday (18 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (6 on average).

Rainfall in Heathrow by month

Plan your trip to Heathrow by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in London Heathrow Airport ranges from 40.0 - 70.0 inches per month. January is typically the wettest month, when rainfall can reach 70.0 mm. July is typically the driest time to visit London Heathrow Airport when rainfall is around 40.0 mm.

Temperature in Heathrow by month

Plan your trip to Heathrow by taking into account the average temperature totals by month.

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 17.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 4.0 C).

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 4 February 2025.
Read reviews from past customers who have flown Delta, KLM and Finnair from Seattle to London. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very Good
8,415 reviews
Check prices

Comfort

8.0

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Delta
8.0
Very Good
8,415 reviews
Delta
8.0
Very Good
8,415 reviews
Check prices

Comfort

8.0

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

KLM
7.8
Good
1,334 reviews
Delta
8.0
Very Good
8,415 reviews
Check prices

Comfort

8.0

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Finnair
7.6
Good
1,284 reviews
Delta
8.0
Very Good
8,415 reviews
Check prices

Comfort

8.0

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

SWISS
7.5
Good
1,582 reviews
Delta
8.0
Very Good
8,415 reviews
Check prices

Comfort

8.0

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Virgin Atlantic
7.5
Good
658 reviews
Delta
8.0
Very Good
8,415 reviews
Check prices

Comfort

8.0

Overall

8.0

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

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 12 flights from Seattle/Tacoma Intl to London Heathrow per day from 3 different airlines.

  • 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 £487. Other airlines that can offer you cheap pricing are Iberia, from £493, and Virgin Atlantic, from £506. You may be able to fly from Seattle to London Heathrow Airport for 27% 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 £228 on WestJet. Other airlines that offer cheap prices include Icelandair from £244 and JetBlue from £283 one-way.

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

    Consider Aeromexico (84%), Singapore Airlines (83%) or American Airlines (74%) 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 £554, our data shows the cheapest flight currently is £272. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £489 for that flight.

  • 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 holiday packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Heathrow?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Heathrow.

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

    Yes. Cheapflights offers flight deals from Seattle to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

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

    Currently, January is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of £112). Flying from Seattle to London Heathrow Airport in August is currently the most expensive (average of £162). 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

Travelling to a place near Seattle?

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Browse thousands of different options on Cheapflights for your next trip

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Top 3 airlines flying from Seattle to Heathrow

Discover the top 3 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 4 February 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£392Average£475FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Virgin AtlanticCheapest£487Average£707FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapest£497Average£933FlexibilityNo cancel feeOn-time70%
Search British Airways flights

Fly with Cheapflights

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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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