Find flights
Deals
When to book
Airlines
FAQs

Cheap flights from Seattle to London Heathrow Airport from C$ 382

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 5/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
25 Feb — 4 Mar1
1 adult

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

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 20 February 2025.

Round-trip from

C$ 845

One-way from

C$ 382

Popular in

June

Cheapest in

November

Average price

C$ 1,029

Good round-trip deal

C$ 1,054 or less

Good one-way deal

C$ 582 or less
Finnair
  • Finnair
  • 29/4-7/5
  • 1 total stop
  • 23h 50m total
  • Seattle to London
Search Deals
WestJet
  • WestJet
  • 5/3
  • 1 total stop
  • 13h 35m total
  • Seattle to London
Search Deals
Highest demand for flights based on searches. 22% potential increase in price (C$ 481 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (C$ 78 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 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 20 February 2025.

Tue 29/41:30 p.m.SEA - LHR
Nonstop9h 20mFinnair
Wed 7/59:30 a.m.LHR - SEA
1 stop14h 30mFinnair
Deal found 19/2C$ 845
Sat 1/32:35 p.m.SEA - LHR
1 stop12h 15mIcelandair
Tue 11/38:40 p.m.LHR - SEA
1 stop28h 20mIcelandair
Deal found 20/2C$ 875
Wed 5/310:35 a.m.SEA - LHR
1 stop15h 35mLufthansa
Tue 18/37:40 a.m.LHR - SEA
1 stop13h 40mLufthansa
Deal found 19/2C$ 877
Wed 12/37:55 p.m.SEA - LHR
Nonstop9h 45mKLM
Tue 18/36:30 a.m.LHR - SEA
1 stop13h 10mKLM
Deal found 20/2C$ 878
Sun 23/33:05 p.m.SEA - LHR
1 stop12h 05mUnited Airlines
Wed 2/49:00 a.m.LHR - SEA
1 stop15h 59mUnited Airlines
Deal found 19/2C$ 879
Thu 6/37:10 a.m.SEA - LHR
1 stop16h 45mDelta
Sun 9/36:30 a.m.LHR - SEA
1 stop13h 10mDelta
Deal found 20/2C$ 884
Sun 6/47:10 a.m.SEA - LHR
1 stop17h 40mVirgin Atlantic
Sun 13/41:25 p.m.LHR - SEA
Nonstop10h 20mVirgin Atlantic
Deal found 19/2C$ 906
Sun 9/310:55 a.m.SEA - LHR
2 stops37h 35mMultiple Airlines
Tue 25/37:40 a.m.LHR - SEA
1 stop13h 40mMultiple Airlines
Deal found 20/2C$ 925
Sun 27/48:20 p.m.SEA - LHR
Nonstop9h 20mBritish Airways
Thu 8/54:30 p.m.LHR - SEA
Nonstop9h 50mBritish Airways
Deal found 19/2C$ 940
Fri 21/31:50 p.m.SEA - LHR
1 stop35h 05mAir France
Mon 31/31:25 p.m.LHR - SEA
Nonstop10h 20mAir France
Deal found 19/2C$ 993
Sat 18/1010:39 p.m.SEA - LHR
1 stop14h 06mJetBlue
Fri 24/108:25 a.m.LHR - SEA
1 stop22h 01mJetBlue
Deal found 20/2C$ 1,000
Fri 19/94:20 p.m.SEA - LHR
1 stop13h 15mScandinavian Airlines
Sat 20/93:35 p.m.LHR - SEA
2 stops30h 25mScandinavian Airlines
Deal found 19/2C$ 1,094

Find flights from Seattle to Heathrow within your budget

Customize 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 629,999 searches. Data last updated 20 February 2025.

Fly from

Seattle

Fly to

Heathrow

Route

Depart

Return

Price

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 29/4

1:30 p.m.-6:50 a.m.

Nonstop9h 20m

London Heathrow

Wed 7/5

9:30 a.m.-4:00 p.m.

1 stop14h 30m

C$ 845

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 6/3

2:35 p.m.-7:30 p.m.

1 stop20h 55m

London Heathrow

Tue 11/3

8:40 p.m.-6:00 p.m.

1 stop28h 20m

C$ 875

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 5/3

10:35 a.m.-10:10 a.m.

1 stop15h 35m

London Heathrow

Tue 18/3

7:40 a.m.-2:20 p.m.

1 stop13h 40m

C$ 877

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 12/3

7:55 p.m.-12:40 p.m.

Nonstop9h 45m

London Heathrow

Sun 16/3

11:45 a.m.-12:40 p.m.

1 stop31h 55m

C$ 878

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 25/3

8:10 a.m.-11:05 a.m.

2 stops19h 55m

London Heathrow

Wed 2/4

10:50 a.m.-4:59 p.m.

1 stop14h 09m

C$ 886

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 6/4

8:20 p.m.-2:15 p.m.

Nonstop9h 55m

London Heathrow

Sun 13/4

6:30 p.m.-8:50 p.m.

Nonstop10h 20m

C$ 898

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 6/4

7:10 a.m.-8:50 a.m.

1 stop17h 40m

London Heathrow

Sun 13/4

1:25 p.m.-3:45 p.m.

Nonstop10h 20m

C$ 906

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 9/3

10:55 a.m.-7:30 a.m.

2 stops37h 35m

London Heathrow

Tue 25/3

7:40 a.m.-2:20 p.m.

1 stop13h 40m

C$ 925

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 27/4

8:20 p.m.-1:40 p.m.

Nonstop9h 20m

London Heathrow

Thu 8/5

4:30 p.m.-6:20 p.m.

Nonstop9h 50m

C$ 940

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 21/3

1:50 p.m.-7:55 a.m.

1 stop35h 05m

London Heathrow

Mon 31/3

1:25 p.m.-3:45 p.m.

Nonstop10h 20m

C$ 993

Flights are sorted by cheapest round-trip flights first.

Deals found on 19/2

Showing 1-10 of 29 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 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.

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 round-trip flight from Seattle to Heathrow. Price data was last updated on 14 February 2025.

The best time to book flights from Seattle to London Heathrow Airport is 44 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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 C$ 560). Flying from Seattle to London Heathrow Airport in July is currently the most expensive (average of C$ 874). 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 20 February 2025.

Unlike in the afternoon, when flights are generally more expensive, you can save up to 30% on flights from Seattle to London Heathrow Airport by exploring options for tickets in the morning.

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 20 February 2025.

The most flights from SEA to LHR are scheduled on a Wednesday (16 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (12 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 mm 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 20 February 2025.
To help decide which airline to fly from Seattle to London, see what other customers have to say about Delta, Alaska Airlines and KLM. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
8,227 reviews
Check prices

Boarding

8.2

Comfort

8.0

Food

7.3

Entertainment

7.9

Overall

8.0

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
8,227 reviews
Delta
8.0
Very good
8,227 reviews
Check prices

Boarding

8.2

Comfort

8.0

Food

7.3

Entertainment

7.9

Overall

8.0

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.

Alaska Airlines
8.0
Very good
9,691 reviews
Delta
8.0
Very good
8,227 reviews
Check prices

Boarding

8.2

Comfort

8.0

Food

7.3

Entertainment

7.9

Overall

8.0

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
1,333 reviews
Delta
8.0
Very good
8,227 reviews
Check prices

Boarding

8.2

Comfort

8.0

Food

7.3

Entertainment

7.9

Overall

8.0

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
1,274 reviews
Delta
8.0
Very good
8,227 reviews
Check prices

Boarding

8.2

Comfort

8.0

Food

7.3

Entertainment

7.9

Overall

8.0

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
1,572 reviews
Delta
8.0
Very good
8,227 reviews
Check prices

Boarding

8.2

Comfort

8.0

Food

7.3

Entertainment

7.9

Overall

8.0

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?

    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 13 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 7 airlines have flights from the Seattle airport to London Heathrow. It is only a 18.4 km journey to Seattle/Tacoma Intl (SEA) from Seattle’s city centre.

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

    Flying on Finnair is currently your cheapest option to London Heathrow Airport, with prices starting at C$ 845. Additional round-trip tickets that might be worth considering are offered by Icelandair and Lufthansa, with the lowest prices starting at C$ 875 and C$ 877, respectively. Users have found that Finnair is 29% cheaper than the other options available to this destination.

  • 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 C$ 382 on WestJet. Other airlines that offer cheap prices include Icelandair from C$ 411 and Iberia from C$ 590 one-way.

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

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to London Heathrow Airport on time: Aeromexico (82%), Singapore Airlines (81%), American Airlines (72%).

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

    While on average a flight from Seattle to London Heathrow Airport is generally C$ 1,519, our data shows the cheapest flight currently is C$ 412. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay C$ 877 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 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, January is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of C$ 560). Flying from Seattle to London Heathrow Airport in July is currently the most expensive (average of C$ 874). 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
Brentford
Hounslow
Slough
Luton
Milton Keynes
Romford
Watford
Bromley
Bedford
Southall

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.
Seattle to Gatwick flights

Top 7 airlines flying from Seattle to Heathrow

Discover the top 7 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 629,999 searches. Data last updated 20 February 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapestC$ 626AverageC$ 868FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
IberiaCheapestC$ 648AverageC$ 895FlexibilityNo cancel feeOn-time77%
Search Iberia flights
Air FranceCheapestC$ 730AverageC$ 1,117FlexibilityNo cancel feeOn-time77%
Search Air France flights
KLMCheapestC$ 730AverageC$ 924FlexibilityNo cancel feeOn-time75%
Search KLM flights
DeltaCheapestC$ 868AverageC$ 1,095FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Virgin AtlanticCheapestC$ 872AverageC$ 1,070FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapestC$ 878AverageC$ 1,225FlexibilityNo cancel feeOn-time70%
Search British Airways flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers 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?

900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Heathrow from Seattle today with Cheapflights!

Why should you use Cheapflights to find cheap flight tickets from Seattle to Heathrow?

Millions of users choose and trust Cheapflights to book the best flight deals from Seattle to Heathrow for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.

Can Cheapflights find flights from Seattle to Heathrow with no change fees?

Users can book flights with no change fees policies with our dedicated filters. Book flights from Seattle to Heathrow flexibly with Cheapflights today.

Can Cheapflights notify me if prices for flights from Seattle to Heathrow become cheaper?

Yes, Cheapflights offers price alerts on Seattle to Heathrow flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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.