Find flights
Deals
When to book
Airlines
FAQs

Cheap flights from Seattle to London Heathrow Airport from £213

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 7/5. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
13 Apr — 20 Apr1
1 adult

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London Heathrow are usually found in March or November, booked 32 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 8 April 2025.

Round-trip from

£466

One-way from

£213

Popular in

June

Cheapest in

March

Average price

£549

Good round-trip deal

£531 or less

Good one-way deal

£369 or less
Iberia
  • Iberia
  • 29/4-13/5
  • 1 total stop
  • 24h 55m total
  • Seattle to London
Search Deals
Icelandair
  • Icelandair
  • 7/5
  • 1 total stop
  • 12h 10m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 20% potential increase in price (£130 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (£21 potential savings vs. average return price).
Search Deals
Average for round-trip flights in April 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 8 April 2025.

Tue 29/411:20SEA - LHR
1 stop15h 10mIberia
Tue 13/509:25LHR - SEA
Nonstop9h 45mIberia
Deal found 7/4£466
Tue 15/723:30SEA - LHR
1 stop12h 50mIcelandair
Tue 21/1021:25LHR - SEA
1 stop28h 25mIcelandair
Deal found 7/4£466
Wed 30/410:22SEA - LHR
1 stop14h 38mAmerican Airlines
Wed 7/509:30LHR - SEA
1 stop14h 30mAmerican Airlines
Deal found 7/4£467
Wed 8/1010:00SEA - LHR
2 stops16h 00mMultiple Airlines
Thu 16/1008:40LHR - SEA
2 stops17h 56mMultiple Airlines
Deal found 7/4£472
Tue 15/410:25SEA - LHR
2 stops17h 25mLufthansa
Wed 30/409:00LHR - SEA
1 stop15h 59mLufthansa
Deal found 8/4£474
Tue 29/410:25SEA - LHR
2 stops17h 25mAir Canada
Tue 20/508:45LHR - SEA
2 stops18h 52mAir Canada
Deal found 7/4£477
Mon 21/407:15SEA - LHR
1 stop22h 55mUnited Airlines
Fri 9/509:00LHR - SEA
1 stop15h 59mUnited Airlines
Deal found 7/4£479
Wed 16/417:35SEA - LHR
Nonstop9h 45mDelta
Tue 29/409:00LHR - SEA
1 stop16h 40mDelta
Deal found 7/4£481
Mon 28/420:20SEA - LHR
Nonstop9h 55mVirgin Atlantic
Sat 10/513:25LHR - SEA
Nonstop10h 20mVirgin Atlantic
Deal found 8/4£485
Wed 20/818:45SEA - LHR
1 stop13h 10mAer Lingus
Thu 28/809:50LHR - SEA
1 stop15h 09mAer Lingus
Deal found 7/4£495
Tue 19/812:00SEA - LHR
2 stops22h 30mScandinavian Airlines
Wed 3/906:40LHR - SEA
1 stop15h 10mScandinavian Airlines
Deal found 7/4£508
Tue 15/413:30SEA - LHR
Nonstop9h 20mBritish Airways
Wed 23/409:50LHR - SEA
Nonstop9h 45mBritish Airways
Deal found 7/4£509

Cheapflights Fare Finder

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 8 April 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

Tue 29/4

11:20-10:30

1 stop15h 10m

London Heathrow

Tue 13/5

09:25-11:10

Nonstop9h 45m

£466

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 15/7

23:30-20:20

1 stop12h 50m

London Heathrow

Wed 22/10

21:25-17:50

1 stop28h 25m

£466

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 30/4

10:22-09:00

1 stop14h 38m

London Heathrow

Wed 7/5

09:30-16:00

1 stop14h 30m

£467

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 29/4

06:00-09:35

1 stop19h 35m

London Heathrow

Tue 6/5

08:45-19:37

2 stops18h 52m

£475

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 29/4

10:25-11:50

2 stops17h 25m

London Heathrow

Tue 20/5

08:45-19:37

2 stops18h 52m

£477

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 21/4

15:24-14:10

1 stop14h 46m

London Heathrow

Wed 30/4

10:50-16:59

1 stop14h 09m

£479

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 23/4

17:35-11:20

Nonstop9h 45m

London Heathrow

Wed 30/4

11:30-17:40

1 stop14h 10m

£481

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 28/4

20:20-14:15

Nonstop9h 55m

London Heathrow

Sat 10/5

13:25-15:45

Nonstop10h 20m

£485

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 20/4

10:25-11:50

2 stops17h 25m

London Heathrow

Wed 30/4

10:50-16:59

1 stop14h 09m

£486

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 20/8

18:45-15:55

1 stop13h 10m

London Heathrow

Thu 28/8

09:50-16:59

1 stop15h 09m

£495

Flights are sorted by cheapest return flights first.

Deals found on 8/4

Showing 1-10 of 32 results
1
2
3
4

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

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 4 April 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 32 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 £164). 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 8 April 2025.

Unlike in the morning, when flights are generally more expensive, you can save up to 12% 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 8 April 2025.

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 (11 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 8 April 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
7,902 reviews
Check prices

Overall

8.0

Crew

8.5

Entertainment

7.9

Comfort

8.0

Food

7.3

Boarding

8.2

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
7,902 reviews
Delta
8.0
Very Good
7,902 reviews
Check prices

Overall

8.0

Crew

8.5

Entertainment

7.9

Comfort

8.0

Food

7.3

Boarding

8.2

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
1,319 reviews
Delta
8.0
Very Good
7,902 reviews
Check prices

Overall

8.0

Crew

8.5

Entertainment

7.9

Comfort

8.0

Food

7.3

Boarding

8.2

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
1,269 reviews
Delta
8.0
Very Good
7,902 reviews
Check prices

Overall

8.0

Crew

8.5

Entertainment

7.9

Comfort

8.0

Food

7.3

Boarding

8.2

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
1,574 reviews
Delta
8.0
Very Good
7,902 reviews
Check prices

Overall

8.0

Crew

8.5

Entertainment

7.9

Comfort

8.0

Food

7.3

Boarding

8.2

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.
Air France
7.4
Good
1,427 reviews
Delta
8.0
Very Good
7,902 reviews
Check prices

Overall

8.0

Crew

8.5

Entertainment

7.9

Comfort

8.0

Food

7.3

Boarding

8.2

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 17 flights from Seattle/Tacoma Intl to London Heathrow per day from 5 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 £466. Other airlines that can offer you cheap pricing are Icelandair, from £466, and American Airlines, from £467. 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 £213 on Icelandair. Other airlines that offer cheap prices include Iberia from £292 and Delta from £308 one-way.

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

    Consider KLM (83%), Singapore Airlines (81%) or Aeromexico (81%) 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 £524, our data shows the cheapest flight currently is £307. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £417 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 £164). 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?

Book flights to Seattle if you plan to visit one of these locations
Hounslow
Deal
Milton Keynes
Gatwick
Luton
Croydon
Slough
Eastbourne
Northampton
Wembley
Crawley
Winchester
Swindon
Southend-on-Sea
Maidstone
Hayes
Ipswich
Ilford
Southall
Dartford

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.

Top 5 airlines flying from Seattle to Heathrow

Discover the top 5 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 8 April 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£378Average£519FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
IberiaCheapest£449Average£572FlexibilityNo cancel feeOn-time77%
Search Iberia flights
Virgin AtlanticCheapest£469Average£742FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapest£478Average£882FlexibilityNo cancel feeOn-time70%
Search British Airways flights
KLMCheapest£516Average£834FlexibilityNo cancel feeOn-time75%
Search KLM flights

Fly with Cheapflights

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!

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.
Site
©2025 Cheapflights