Finnair flights from London Heathrow Airport to Seattle (LHR - SEA)

LHR — SEA
21 Feb — 28 Feb1
1 adult
1 adult, Economy, 0 bags

Cheapflights users flying from London to Seattle on Finnair typically fly into Seattle/Tacoma Intl and depart from London Heathrow. Select your dates above for pricing.

Finnair flights from Heathrow to Seattle in 2026

Find detailed information about Finnair flights from Heathrow to Seattle. Explore the options provided by Finnair to plan your journey from Heathrow to Seattle. Data last updated 22 January 2026.

One-way from

£377

Return from

£387

Popular in

July

Cheapest in

February

Average price (all airlines)

£502
Finnair
  • Finnair
  • 21/4
  • Nonstop
  • 9h 45m total
  • London to Seattle
Finnair
  • Finnair
  • 25/5-1/6
  • 2 total stops
  • 46h 17m total
  • London to Seattle
Highest demand for flights from London Heathrow to Seattle/Tacoma Intl; 12% potential price increase.
Best time to find cheap flights from London Heathrow to Seattle/Tacoma Intl; 2% potential price drop.
Average price for all London Heathrow to Seattle/Tacoma Intl flights (one-way and round-trip).
  • How do most travelers feel about Finnair?

    The general consensus from 1,353 Cheapflights users is that Finnair is a 7.6/10. Select your travel dates above for updated prices on flights from London Heathrow Airport to Seattle (LHR-SEA).

  • Can I get a flight from London Heathrow Airport to Seattle on Finnair for under £521?

    London Heathrow Airport to Seattle flights on Finnair are currently available under £521. 10 flights have been found by Cheapflights users under that amount. To find flights for your dates, click here.

Find Finnair flight deals from Heathrow to Seattle

Enter your travel dates to find the best prices.

Cheapest Finnair flights from Heathrow to Seattle
Explore the most affordable Finnair flight options available from Heathrow to Seattle. Find the lowest fares with prices last updated on 22 January 2026.

Tue 27/116:30
LHR
-
SEA
1 stop37h 17m
Finnair
Tue 24/206:44
SEA
-
LHR
1 stop16h 06m
Finnair
Deal found 21/1£411
Wed 28/111:55
LHR
-
SEA
1 stop16h 50m
Finnair
Sat 28/213:35
SEA
-
LHR
Nonstop9h 35m
Finnair
Deal found 21/1£483
Sat 31/112:35
LHR
-
SEA
2 stops19h 24m
Finnair
Sun 15/200:07
SEA
-
LHR
2 stops22h 13m
Finnair
Deal found 21/1£508

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

Currently, the most affordable month to book a Finnair flight from London Heathrow Airport to Seattle in March, with an average price of £396. Conversely, traveling with Finnair from London Heathrow Airport to Seattle in February will be the most expensive, with an average cost of £897. Various factors influence flight prices, so comparing airlines, departure airports, and times can help reduce costs.

Best time to book a flight from Heathrow to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Heathrow 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.

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.

Fly from Heathrow to Seattle on another airline

Consider alternative airlines that service the Seattle area. Flight routes are based on user searches made on Cheapflights and were last updated on 22 January 2026.

See what others are saying about Finnair

Read reviews and see what other travellers are saying about their experiences with Finnair. Get insights from real passengers regarding the airline's services, customer satisfaction, and overall travel experience. Use these reviews to inform your decision when choosing Finnair for your next flight. Reviews last updated 22 January 2026.
Finnair
7.6
Good
1,353 reviews
Overview

Entertainment

6.9

Comfort

7.5

Food

6.7

Crew

8.2

Boarding

7.7

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.