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 4/8. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
4 May — 11 May1
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 29 April 2025.

Round-trip from

£467

One-way from

£213

Popular in

June

Cheapest in

March

Average price

£528

Good round-trip deal

£497 or less

Good one-way deal

£377 or less
Icelandair
  • Icelandair
  • 23/8-7/9
  • 2 total stops
  • 34h 50m total
  • Seattle to London
Icelandair
  • Icelandair
  • 4/8
  • 1 total stop
  • 17h 20m total
  • Seattle to London
Highest demand for flights based on searches. 19% potential increase in price (£114 potential increase over avg. return price).
Cheapest flight prices on average. 4% potential price decrease (£19 potential savings vs. average return price).
Average for round-trip flights in April 2025
Price to beat on a round-trip flight from Seattle/Tacoma Intl to London Heathrow.
Price to beat on a one-way flight from Seattle/Tacoma Intl to London Heathrow.

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 29 April 2025.

Sat 23/819:00SEA - LHR
1 stop17h 20mIcelandair
Sat 6/921:25LHR - SEA
1 stop22h 00mIcelandair
Deal found 27/4£467
Wed 24/916:20SEA - LHR
1 stop33h 00mScandinavian Airlines
Wed 15/1006:40LHR - SEA
1 stop15h 20mScandinavian Airlines
Deal found 28/4£471
Wed 1/1020:20SEA - LHR
Nonstop9h 20mIberia
Tue 14/1009:25LHR - SEA
Nonstop9h 45mIberia
Deal found 29/4£505
Wed 3/907:20SEA - LHR
1 stop15h 10mUnited Airlines
Wed 17/906:30LHR - SEA
2 stops20h 06mUnited Airlines
Deal found 28/4£507
Sun 9/1105:50SEA - LHR
2 stops17h 20mMultiple Airlines
Wed 19/1106:30LHR - SEA
2 stops15h 56mMultiple Airlines
Deal found 28/4£507
Tue 14/1017:35SEA - LHR
Nonstop9h 45mVirgin Atlantic
Thu 23/1017:25LHR - SEA
Nonstop10h 25mVirgin Atlantic
Deal found 28/4£509
Tue 26/807:20SEA - LHR
1 stop15h 10mAir Canada
Wed 10/908:40LHR - SEA
2 stops32h 41mAir Canada
Deal found 28/4£512
Tue 7/1010:00SEA - LHR
2 stops17h 50mLufthansa
Tue 4/1106:35LHR - SEA
1 stop14h 45mLufthansa
Deal found 28/4£515
Tue 23/920:25SEA - LHR
Nonstop9h 50mDelta
Tue 7/1006:30LHR - SEA
1 stop13h 20mDelta
Deal found 28/4£516
Wed 6/813:30SEA - LHR
Nonstop9h 20mBritish Airways
Wed 13/816:30LHR - SEA
Nonstop9h 50mBritish Airways
Deal found 29/4£533
Tue 23/913:45SEA - LHR
2 stops21h 35mSWISS
Sat 4/1020:05LHR - SEA
2 stops30h 31mSWISS
Deal found 28/4£564
Thu 10/723:25SEA - LHR
1 stop13h 20mJetBlue
Fri 19/911:55LHR - SEA
1 stop18h 17mJetBlue
Deal found 28/4£572

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 29 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

Sat 23/8

19:00-20:20

1 stop17h 20m

London Heathrow

Sat 6/9

21:25-11:25

1 stop22h 00m

£467

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 24/9

16:20-09:20

1 stop33h 00m

London Heathrow

Tue 14/10

18:40-14:00

1 stop27h 20m

£471

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 3/9

10:00-09:35

2 stops15h 35m

London Heathrow

Tue 30/9

06:00-18:36

2 stops20h 36m

£500

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 1/10

20:20-13:40

Nonstop9h 20m

London Heathrow

Tue 14/10

09:25-11:10

Nonstop9h 45m

£505

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 3/9

07:20-06:30

1 stop15h 10m

London Heathrow

Wed 17/9

06:30-18:36

2 stops20h 06m

£507

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 14/10

17:35-11:20

Nonstop9h 45m

London Heathrow

Thu 23/10

17:25-19:50

Nonstop10h 25m

£509

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 26/8

07:20-06:30

1 stop15h 10m

London Heathrow

Wed 10/9

08:40-09:21

2 stops32h 41m

£512

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 7/10

10:00-11:50

2 stops17h 50m

London Heathrow

Tue 4/11

06:35-13:20

1 stop14h 45m

£515

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 23/9

17:35-11:20

Nonstop9h 45m

London Heathrow

Thu 2/10

06:30-11:50

1 stop13h 20m

£516

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 6/8

13:30-06:50

Nonstop9h 20m

London Heathrow

Wed 13/8

16:30-18:20

Nonstop9h 50m

£533

Flights are sorted by cheapest return flights first.

Deals found on 28/4

Showing 1-10 of 25 results
1
2
3

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 25 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 29 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 29 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 (16 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 29 April 2025.
Read reviews from past customers who have flown Delta, SWISS and Air France from Seattle to London. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Comfort

7.9

Boarding

8.2

Food

7.3

Entertainment

7.9

Crew

8.5

Overall

8.0

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.
8.0
Very Good

Comfort

7.9

Boarding

8.2

Food

7.3

Entertainment

7.9

Crew

8.5

Overall

8.0

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.

Comfort

7.9

Boarding

8.2

Food

7.3

Entertainment

7.9

Crew

8.5

Overall

8.0

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.

Comfort

7.9

Boarding

8.2

Food

7.3

Entertainment

7.9

Crew

8.5

Overall

8.0

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.

Comfort

7.9

Boarding

8.2

Food

7.3

Entertainment

7.9

Crew

8.5

Overall

8.0

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.

Comfort

7.9

Boarding

8.2

Food

7.3

Entertainment

7.9

Crew

8.5

Overall

8.0

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 21 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 £467. Other airlines that can offer you cheap pricing are Scandinavian Airlines, from £471, and Iberia, from £477. You may be able to fly from Seattle to London Heathrow Airport for 23% 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 Scandinavian Airlines from £298 and Virgin Atlantic from £299 one-way.

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

    Consider Scandinavian Airlines (90%), KLM (85%) or Aeromexico (85%) 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 £517, our data shows the cheapest flight currently is £294. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay £354 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
Deal
Hounslow
Milton Keynes
Gatwick
Luton
Slough
Croydon
Eastbourne
Northampton
Ilford
Hayes
Southend-on-Sea
Crawley
Wembley
Ipswich
Maidstone
Winchester
Swindon
Folkestone
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 29 April 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£362Average£495FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
IberiaCheapest£431Average£549FlexibilityNo cancel feeOn-time77%
Search Iberia flights
Virgin AtlanticCheapest£450Average£712FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapest£459Average£846FlexibilityNo cancel feeOn-time70%
Search British Airways flights
KLMCheapest£495Average£800FlexibilityNo 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.