£351 Cheap Flights to King County

View £351 flight on Thu, 10 Sept 2026Opens in a new window

Popular airlines to King County

  • Alaska Airlines

  • American Airlines

  • Delta

  • United

  • Southwest Airlines

  • Frontier Airlines

  • JetBlue Airways

  • Be in the know

    Get alerts if flight prices drop or rise*

  • Book smarter

    Save up to 25% on select hotels after you book a flight*

  • Earn twice

    Earn your airline miles on top of our rewards
    Sign in

Cheap round-trip flights to King County

Prices were available within the past 7 days and start at £351 for one-way flights and £406 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Icelandair
Fri, 23 Oct - Fri, 30 Oct
LGW
London
SEA
Seattle
£406 Return, found 8 hours ago
£406
Return
found 8 hours ago
Select Icelandair flight, departing Fri, 23 Oct from London to Seattle, returning Fri, 30 Oct, priced at £406 found 8 hours ago
Aer Lingus
Mon, 16 Nov - Sun, 22 Nov
LHR
London
SEA
Seattle
£412 Return, found 4 hours ago
£412
Return
found 4 hours ago
Select Aer Lingus flight, departing Mon, 16 Nov from London to Seattle, returning Sun, 22 Nov, priced at £412 found 4 hours ago
KLM
Wed, 7 Oct - Wed, 21 Oct
LHR
London
SEA
Seattle
£454 Return, found 14 hours ago
£454
Return
found 14 hours ago
Select KLM flight, departing Wed, 7 Oct from London to Seattle, returning Wed, 21 Oct, priced at £454 found 14 hours ago
Delta
Thu, 22 Oct - Mon, 26 Oct
LHR
London
SEA
Seattle
£454 Return, found 7 hours ago
£454
Return
found 7 hours ago
Select Delta flight, departing Thu, 22 Oct from London to Seattle, returning Mon, 26 Oct, priced at £454 found 7 hours ago
British Airways
Wed, 28 Oct - Sat, 7 Nov
LHR
London
SEA
Seattle
£458 Return, found 8 hours ago
£458
Return
found 8 hours ago
Select British Airways flight, departing Wed, 28 Oct from London to Seattle, returning Sat, 7 Nov, priced at £458 found 8 hours ago
American Airlines
Tue, 3 Nov - Tue, 17 Nov
LGW
London
SEA
Seattle
£459 Return, found 2 hours ago
£459
Return
found 2 hours ago
Select American Airlines flight, departing Tue, 3 Nov from London to Seattle, returning Tue, 17 Nov, priced at £459 found 2 hours ago
Air France
Tue, 20 Apr - Mon, 26 Apr
LHR
London
SEA
Seattle
£462 Return, found 5 hours ago
£462
Return
found 5 hours ago
Select Air France flight, departing Tue, 20 Apr from London to Seattle, returning Mon, 26 Apr, priced at £462 found 5 hours ago
Virgin Atlantic
Sat, 24 Oct - Fri, 30 Oct
LHR
London
SEA
Seattle
£462 Return, found 3 hours ago
£462
Return
found 3 hours ago
Select Virgin Atlantic flight, departing Sat, 24 Oct from London to Seattle, returning Fri, 30 Oct, priced at £462 found 3 hours ago
Air France
Wed, 7 Oct - Wed, 21 Oct
LHR
London
SEA
Seattle
£467 Return, found 14 hours ago
£467
Return
found 14 hours ago
Select Air France flight, departing Wed, 7 Oct from London to Seattle, returning Wed, 21 Oct, priced at £467 found 14 hours ago
Swiss International Air Lines
Wed, 30 Sept - Wed, 7 Oct
LGW
London
SEA
Seattle
£470 Return, found 5 hours ago
£470
Return
found 5 hours ago
Select Swiss International Air Lines flight, departing Wed, 30 Sept from London to Seattle, returning Wed, 7 Oct, priced at £470 found 5 hours ago
Book with confidence

Top tips for booking flights to King County from UK

Get ready to fly to King County

Prepare your luggage and book your flights to King County with Expedia. We offer a seamless flight booking experience, with a wide range of King County plane tickets to choose from. If you need help finding some of the best deals for cheap flights to King County in 2026, we are always available to assist you. Book your flights to King County today and let the adventure begin!

Find the best tickets to King County

To find some of the best tickets to King County in 2026, use Expedia's powerful search engine to compare dates and the different departure and arrival airports for your trip. Whether you're after direct flights to King County or last-minute flights to King County, you can filter and sort your search results, making it easy to find the ideal flight to King County.

Airlines fly to King County

There are 20 different airlines that fly to King County including some of the most trusted names in the business. To book flights to King County with your favourite airline, take a look at Expedia's flight listings and try out different dates to find some of the best King County plane tickets.

Find the cheapest flights to King County

By booking early you may find some of the best deals for King County flights from the UK, including King County direct flights. You can usually find affordable and cheap flights to King County, whether one-way from £351 or round-trip from £406, with Expedia if you book your trip far enough in advance.

Find the best airports for cheap flights to King County

Try searching for different King County airports with Expedia to find some of the cheapest flights to King County. Flights from London (LGW) to Seattle (SEA) usually have the lowest price from £351.

Why book your flights to King County with Expedia

Expedia offers great deals on King County air fares from £351 to cater to every budget. Not only is Expedia one of the top platforms to book flights to King County from the UK, it is also your one-stop shop for booking hotels, car rentals, and more.

 

*Prices and availability are subject to change. Additional terms apply.

Trending flights to King County

These prices were available within the past 7 days. Prices quoted are per person, return, for the period specified. Prices and availability are subject to change. Additional terms apply.

Icelandair
Fri, 23 Oct - Fri, 30 Oct
LGW
London
SEA
Seattle
£406 Return, found 8 hours ago
£406
Return
found 8 hours ago
Select Icelandair flight, departing Fri, 23 Oct from London to Seattle, returning Fri, 30 Oct, priced at £406 found 8 hours ago

Frequently asked questions

How do I find cheap flights to King County that have flexible change policies?
We know that things can change in the blink of an eye, so locking in a flexible ticket with Expedia is always a clever idea. Tick the "No change fee" box underneath the "Flexible change policies" filter. Your low-cost, flexible flight to King County is only a few clicks away.
Which airlines fly to King County?
When you're ready to book your ticket to or near King County, these carriers look forward to welcoming you on board:

  • Alaska Airlines - 8,781 flights to or near King County each month, including 8,781 flights to Seattle - Tacoma Intl. Airport (SEA) per month.
  • Delta Air Lines - 4,186 flights to or near King County each month, including 4,186 flights to Seattle - Tacoma Intl. Airport (SEA) per month.
  • United Airlines - 828 flights to or near King County each month, including 828 flights to Seattle - Tacoma Intl. Airport (SEA) per month.

How can I find cheap tickets to King County?
Book in advance, fly in or out of nearby airports, avoid peak travel periods — there are plenty of ways! One more is to take advantage of Expedia's "flexible dates" feature. Search for your King County flight, then compare the prices for nearby dates. In the last seven days, the best price for a flight to King County was £406.
How much is a flight to King County?
There were plenty of affordable fares for the taking in the last seven days, with the price of a return flight to King County ranging between £406 and £470. Many lucky travellers nabbed one-way tickets from London (LGW) for only £351.
What are the most popular airports to fly into in King County?
Depending on which carrier you travel with and departure city, one of these leading airports will be your entry point to King County:

  • Seattle - Tacoma Intl. Airport (SEA) - 15,456 flights per month.
  • Boeing Field Airport (BFI) - 247 flights per month.

When is the cheapest time to fly to King County?
If you'd prefer to spend your money experiencing King County rather than on your flight there, depart early in the week. The most cost-effective day to travel is generally Tuesday, with Monday running a close second. With many folks travelling over the weekend, Saturday often has the highest fares.
How much is a plane ticket to King County?
In the last seven days, plane fares to King County varied from £406 to £470.
What is the best time to go to King County?
A terrific time to check out Seattle is after June 20 when summer starts. In King County's most populated city, temperatures range from 13ºC to 24ºC during this time — glorious weather for touring around! March, April and May are the most popular months for tourists.
What months are the cheapest to book a flight to King County?
February is the cheapest month to reserve a seat for your King County adventure. Airfares cost the most over the festive month of December, so steer clear of this time if possible.

Book with confidence

Top tips for booking flights to King County from UK

Get ready to fly to King County

Prepare your luggage and book your flights to King County with Expedia. We offer a seamless flight booking experience, with a wide range of King County plane tickets to choose from. If you need help finding some of the best deals for cheap flights to King County in 2026, we are always available to assist you. Book your flights to King County today and let the adventure begin!

Find the best tickets to King County

To find some of the best tickets to King County in 2026, use Expedia's powerful search engine to compare dates and the different departure and arrival airports for your trip. Whether you're after direct flights to King County or last-minute flights to King County, you can filter and sort your search results, making it easy to find the ideal flight to King County.

Airlines fly to King County

There are 20 different airlines that fly to King County including some of the most trusted names in the business. To book flights to King County with your favourite airline, take a look at Expedia's flight listings and try out different dates to find some of the best King County plane tickets.

Find the cheapest flights to King County

By booking early you may find some of the best deals for King County flights from the UK, including King County direct flights. You can usually find affordable and cheap flights to King County, whether one-way from £351 or round-trip from £406, with Expedia if you book your trip far enough in advance.

Find the best airports for cheap flights to King County

Try searching for different King County airports with Expedia to find some of the cheapest flights to King County. Flights from London (LGW) to Seattle (SEA) usually have the lowest price from £351.

Why book your flights to King County with Expedia

Expedia offers great deals on King County air fares from £351 to cater to every budget. Not only is Expedia one of the top platforms to book flights to King County from the UK, it is also your one-stop shop for booking hotels, car rentals, and more.

 

*Prices and availability are subject to change. Additional terms apply.

Top tips for booking flights to King County from UK

Travel information

King County Flights Information

Airlines serving
American Airlines, KLM, Swiss International Air Lines, JetBlue Airways, Finnair, Air Canada, Delta, Lufthansa, Icelandair, Aer Lingus, British Airways, Air France, Virgin Atlantic
Roundtrip price
from £406
King County Flights Information
*Available to Expedia members.