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Cheap flights from Seattle to London Heathrow Airport from C$ 396

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 9/1. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — LHR
25 Dec — 1 Jan1
1 adult

The best prices from Seattle/Tacoma Intl to London Heathrow are usually found in November or October, booked 75 days in advance, depart on a Monday or Tuesday and return on a Wednesday

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 December 2024.

Round-trip from

C$ 870

One-way from

C$ 396

Popular in

June

Cheapest in

November

Average price

C$ 1,390
Icelandair
  • Icelandair
  • 19/1-24/1
  • 2 total stops
  • 33h 40m total
  • Seattle to London
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9/1
  • 9/1
  • 2 total stops
  • 40h 37m total
  • Seattle to London
Search Deals
High demand for flights, 21% potential price rise
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Best time to find cheap flights, 4% potential price drop
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Average for round-trip flights in December 2024
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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 20 December 2024.

Sun 29/122:35 p.m.SEA - LHR
1 stop12h 15mIcelandair
Mon 27/112:15 p.m.LHR - SEA
1 stop12h 45mIcelandair
Deal found 19/12C$ 976
Tue 31/1210:35 a.m.SEA - LHR
1 stop15h 35mLufthansa
Fri 31/17:40 a.m.LHR - SEA
1 stop13h 40mLufthansa
Deal found 19/12C$ 1,181
Mon 30/125:45 a.m.SEA - LHR
1 stop20h 25mUnited Airlines
Thu 30/16:30 a.m.LHR - SEA
1 stop13h 40mUnited Airlines
Deal found 19/12C$ 1,182
Sun 29/125:45 p.m.SEA - LHR
Nonstop9h 25mDelta
Wed 29/16:30 a.m.LHR - SEA
1 stop13h 21mDelta
Deal found 19/12C$ 1,184
Mon 30/121:30 p.m.SEA - LHR
1 stop12h 30mKLM
Wed 29/13:50 p.m.LHR - SEA
Nonstop10h 30mKLM
Deal found 19/12C$ 1,210
Tue 31/121:35 p.m.SEA - LHR
Nonstop9h 25mFinnair
Tue 28/13:00 p.m.LHR - SEA
Nonstop9h 55mFinnair
Deal found 19/12C$ 1,246
Mon 30/126:50 p.m.SEA - LHR
Nonstop9h 25mBritish Airways
Sat 1/29:25 a.m.LHR - SEA
Nonstop9h 55mBritish Airways
Deal found 19/12C$ 1,318
Wed 25/126:55 p.m.SEA - LHR
Nonstop9h 45mVirgin Atlantic
Fri 31/16:30 a.m.LHR - SEA
1 stop13h 21mVirgin Atlantic
Deal found 20/12C$ 1,430
Mon 30/122:35 p.m.SEA - LHR
1 stop12h 15mMultiple Airlines
Sat 1/212:15 p.m.LHR - SEA
2 stops17h 31mMultiple Airlines
Deal found 19/12C$ 1,447
Mon 30/125:45 p.m.SEA - LHR
Nonstop9h 25mAir France
Wed 8/13:50 p.m.LHR - SEA
Nonstop10h 30mAir France
Deal found 19/12C$ 1,487
Tue 31/129:55 a.m.SEA - LHR
2 stops22h 05mScandinavian Airlines
Wed 29/16:40 a.m.LHR - SEA
2 stops23h 41mScandinavian Airlines
Deal found 19/12C$ 1,672
Wed 25/123:15 p.m.SEA - LHR
1 stop13h 35mWestJet
Mon 30/122:50 p.m.LHR - SEA
2 stops27h 39mWestJet
Deal found 19/12C$ 2,461

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 December 2024.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 19/1

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

1 stop20h 55m

London Heathrow

Fri 24/1

12:15 p.m.-5:00 p.m.

1 stop12h 45m

C$ 870

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 25/1

7:10 a.m.-9:20 a.m.

2 stops18h 10m

London Heathrow

Sun 26/1

7:30 p.m.-10:25 p.m.

2 stops34h 55m

C$ 926

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Thu 20/2

3:15 p.m.-12:50 p.m.

1 stop13h 35m

London Heathrow

Wed 26/2

2:50 p.m.-2:21 p.m.

1 stop31h 31m

C$ 939

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 20/4

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

Nonstop9h 20m

London Heathrow

Wed 7/5

7:30 a.m.-4:00 p.m.

1 stop16h 30m

C$ 940

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/2

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

1 stop15h 35m

London Heathrow

Wed 26/2

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

2 stops20h 00m

C$ 960

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 22/1

5:45 p.m.-11:10 a.m.

Nonstop9h 25m

London Heathrow

Wed 29/1

6:30 a.m.-11:51 a.m.

1 stop13h 21m

C$ 966

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 19/2

8:10 a.m.-6:40 a.m.

1 stop14h 30m

London Heathrow

Wed 26/2

6:30 a.m.-12:10 p.m.

1 stop13h 40m

C$ 969

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 22/1

7:04 p.m.-12:40 p.m.

Nonstop9h 36m

London Heathrow

Wed 29/1

6:30 a.m.-11:51 a.m.

1 stop13h 21m

C$ 972

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 30/3

3:05 p.m.-1:20 p.m.

1 stop14h 15m

London Heathrow

Tue 8/4

6:30 a.m.-12:25 p.m.

1 stop13h 55m

C$ 976

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 22/1

5:45 p.m.-11:10 a.m.

Nonstop9h 25m

London Heathrow

Thu 30/1

12:40 p.m.-2:40 p.m.

Nonstop10h 00m

C$ 994

Flights are sorted by cheapest round-trip flights first.

Deals found on 19/12

Showing 1-10 of 34 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 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 13 December 2024.

The best time to book flights from Seattle to London Heathrow Airport is 75 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 December 2024.

Unlike at noon, when flights are generally more expensive, you can save up to 14% 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 December 2024.

The most flights from SEA to LHR are scheduled on a Tuesday (18 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 December 2024.
To help decide which airline to fly from Seattle to London, see what other customers have to say about WestJet, Finnair and United Airlines. 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
8,601 reviews
Check prices

Overall

8.0

Comfort

8.0

Boarding

8.2

Entertainment

7.9

Food

7.3

Crew

8.6

Reviews

1 / 10

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

Delta
8.0
Very good
8,601 reviews
Delta
8.0
Very good
8,601 reviews
Check prices

Overall

8.0

Comfort

8.0

Boarding

8.2

Entertainment

7.9

Food

7.3

Crew

8.6

Reviews

1 / 10

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

Alaska Airlines
8.0
Very good
9,545 reviews
Delta
8.0
Very good
8,601 reviews
Check prices

Overall

8.0

Comfort

8.0

Boarding

8.2

Entertainment

7.9

Food

7.3

Crew

8.6

Reviews

1 / 10

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

KLM
7.8
Good
1,349 reviews
Delta
8.0
Very good
8,601 reviews
Check prices

Overall

8.0

Comfort

8.0

Boarding

8.2

Entertainment

7.9

Food

7.3

Crew

8.6

Reviews

1 / 10

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

Finnair
7.7
Good
1,285 reviews
Delta
8.0
Very good
8,601 reviews
Check prices

Overall

8.0

Comfort

8.0

Boarding

8.2

Entertainment

7.9

Food

7.3

Crew

8.6

Reviews

1 / 10

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

SWISS
7.6
Good
1,603 reviews
Delta
8.0
Very good
8,601 reviews
Check prices

Overall

8.0

Comfort

8.0

Boarding

8.2

Entertainment

7.9

Food

7.3

Crew

8.6

Reviews

1 / 10

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 14 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 Icelandair is currently your cheapest option to London Heathrow Airport, with prices starting at C$ 870. Additional round-trip tickets that might be worth considering are offered by Scandinavian Airlines and WestJet, with the lowest prices starting at C$ 926 and C$ 939, respectively. Users have found that Icelandair is 27% 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$ 448 on WestJet. Other airlines that offer cheap prices include Icelandair from C$ 451 and KLM from C$ 602 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: KLM (89%), Singapore Airlines (86%), Air France (84%).

  • 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$ 1,573, our data shows the cheapest flight currently is C$ 617. When looking at the most popular route, (Seattle/Tacoma Intl - London Heathrow), you can expect to pay C$ 2,635 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

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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 December 2024.
AirlineCheapestAverageFlexibilityOn-time
IberiaCheapestC$ 634AverageC$ 941FlexibilityNo cancel feeOn-time77%
Search Iberia flights
IcelandairCheapestC$ 635AverageC$ 894FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Air FranceCheapestC$ 740AverageC$ 1,132FlexibilityNo cancel feeOn-time77%
Search Air France flights
KLMCheapestC$ 740AverageC$ 936FlexibilityNo cancel feeOn-time75%
Search KLM flights
Virgin AtlanticCheapestC$ 844AverageC$ 1,085FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
DeltaCheapestC$ 880AverageC$ 1,013FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
British AirwaysCheapestC$ 890AverageC$ 1,173FlexibilityNo 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?

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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.

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