How long is the flight from Belfast to Seattle?

For as low as £574, KLM can have you in Seattle from Belfast in 14h 45m. Airlines will cover a distance of 4472 mi. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

In terms of precipitation, rainfall in Seattle ranges from 18.0 - 168.0 inches per month. November is typically the wettest month, when rainfall can reach 168.0 mm. July is typically the driest time to visit Seattle when rainfall is around 18.0 mm.

If weather is an important factor for your trip to Seattle, 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 19.0 C. Travellers hoping to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 5.0 C).

What is the cheapest time of day to fly from BFS to SEA?

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Belfast to Seattle as you normally would.

What airport do you fly into for flights to Seattle from Belfast?

Most people fly into Seattle/Tacoma Intl (SEA) if they book a flight to Seattle from Belfast. On average, Seattle/Tacoma Intl has 0 inbound flights from Belfast per day from 0 airlines. Seattle/Tacoma Intl is conveniently located just 11.4 mi from Seattle’s city center.

Can I find deals for flights from Belfast to Seattle that include hotel bookings?

Yes. In addition to deals on Belfast to Seattle flights, Cheapflights offers holiday packages that include both flights and hotel.

How can I find direct flights from Belfast to Seattle?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Belfast to Seattle.

Can I find deals for business class flights from Belfast to Seattle?

Yes. Cheapflights offers flight deals from Belfast to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

£409+ Cheap Flights from Belfast to Seattle

Cheap flight deals from Belfast to Seattle

Enter your travel dates to find the best prices.

Cheapest

Best

Last-minute

Cheapest flights from Belfast to Seattle
Explore the most affordable flight options available from Belfast to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 3 September 2026.

Thu 8/1013:00 -

2 stops36h 55m

Mon 12/1015:40 -

2 stops19h 10m

Deal found 31/8£409

Thu 8/1007:00 -

2 stops21h 40m

Mon 12/1019:00 -

2 stops17h 30m

Deal found 31/8£519

Thu 8/1009:50 -

1 stop14h 45m

Mon 12/1017:45 -

1 stop15h 10m

Deal found 31/8£574

Thu 15/1020:35 -

1 stop23h 00m

Mon 19/1015:14 -

2 stops16h 16m

Deal found 2/9£598

Thu 15/1006:10 -

2 stops22h 30m

Thu 22/1019:00 -

2 stops16h 20m

Deal found 31/8£617

Wed 14/1015:40 -

3 stops32h 20m

Wed 21/1019:00 -

3 stops20h 15m

Deal found 29/8£748

Sat 24/1007:20 -

2 stops21h 20m

Sat 31/1015:35 -

3 stops21h 40m

Deal found 3/9£779

Find flight deals from Belfast to Seattle

Round-trip from	£409

8/10-12/10
4 total stops
56h 05m total
Belfast to Seattle

Search Deals

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

BelfastSeattle

BFS Belfast Intl - SEA Seattle/Tacoma Intl

BFSSEA

Belfast Intl

Thu 8/10

13:00-17:55

2 stops36h 55m

Seattle/Tacoma Intl

Mon 12/10

15:40-18:50

2 stops19h 10m

£409

Fastest return journey

BelfastSeattle

BHD Belfast City - SEA Seattle/Tacoma Intl

BHDSEA

Belfast City

Thu 8/10

09:50-16:35

1 stop14h 45m

Seattle/Tacoma Intl

Mon 12/10

17:45-16:55

1 stop15h 10m

£574

BelfastSeattle

BHD Belfast City - SEA Seattle/Tacoma Intl

BHDSEA

Belfast City

Thu 15/10

20:35-11:35

1 stop23h 00m

Seattle/Tacoma Intl

Mon 19/10

15:14-15:30

2 stops16h 16m

£598

BelfastSeattle

BFS Belfast Intl - SEA Seattle/Tacoma Intl

BFSSEA

Belfast Intl

Wed 14/10

15:40-16:00

3 stops32h 20m

Seattle/Tacoma Intl

Wed 21/10

19:00-23:15

3 stops20h 15m

£748

BelfastSeattle

BFS Belfast Intl - SEA Seattle/Tacoma Intl

BFSSEA

Belfast Intl

Thu 15/10

06:10-20:40

2 stops22h 30m

Seattle/Tacoma Intl

Thu 22/10

19:00-23:00

3 stops20h 00m

£752

BelfastSeattle

BFS Belfast Intl - SEA Seattle/Tacoma Intl

BFSSEA

Belfast Intl

Sat 24/10

07:20-20:40

2 stops21h 20m

Seattle/Tacoma Intl

Sat 31/10

15:35-20:15

3 stops21h 40m

£779

Flights are sorted by cheapest return flights first.

Deals found on 31/8

Sorted by cheapest first

Best time to book a flight from Belfast to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Belfast with our price prediction graph.

BF1-SEA

BFS-SEA

BHD-SEA

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 Belfast to Seattle

BF1-SEA

BFS-SEA

BHD-SEA

No data available for this route at this time. Please check back soon.

Related info for your journey

What airport do you fly into for flights to Seattle from Belfast?
Most people fly into Seattle/Tacoma Intl (SEA) if they book a flight to Seattle from Belfast. On average, Seattle/Tacoma Intl has 0 inbound flights from Belfast per day from 0 airlines. Seattle/Tacoma Intl is conveniently located just 11.4 mi from Seattle’s city center.
How long is the flight from Belfast to Seattle?
For as low as £574, KLM can have you in Seattle from Belfast in 14h 45m. Airlines will cover a distance of 4472 mi. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.
Can I find deals for flights from Belfast to Seattle that include hotel bookings?
Yes. In addition to deals on Belfast to Seattle flights, Cheapflights offers holiday packages that include both flights and hotel.
How can I find direct flights from Belfast to Seattle?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Belfast to Seattle.
Can I find deals for business class flights from Belfast to Seattle?
Yes. Cheapflights offers flight deals from Belfast to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

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Cheapflights goes through 900+ travel sites to look for the best flight deals for flights from Belfast to Seattle. Too many options? Cheapflights also provides filters for things like airlines, price ranges, and number of stops to help you make a decision easily.

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

Millions of users choose and trust Cheapflights to book the best flight deals from Belfast to Seattle 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 Belfast to Seattle with no change fees?

Certainly. Search results for flights to Seattle from Belfast shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

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

Yes, Cheapflights offers price alerts on Belfast to Seattle 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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Cheap flights from Belfast to Seattle from £409

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/10. Fares are subject to change and may not be available on all flights or dates of travel.

Cheap flight deals from Belfast to Seattle

Cheapest flights from Belfast to SeattleExplore the most affordable flight options available from Belfast to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 3 September 2026.

Explore the most affordable flight options available from Belfast to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 3 September 2026.

Best flights from Belfast to SeattleDiscover carefully curated flight deals from Belfast to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 3 September 2026.

Discover carefully curated flight deals from Belfast to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 3 September 2026.

Last-minute flights from Belfast to SeattleDiscover last-minute flight deals from Belfast to Seattle. Data last updated 3 September 2026 and is based on user searches.

Discover last-minute flight deals from Belfast to Seattle. Data last updated 3 September 2026 and is based on user searches.

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Best time to book a flight from Belfast to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Belfast with our price prediction graph.

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Related info for your journey

What airport do you fly into for flights to Seattle from Belfast?

How long is the flight from Belfast to Seattle?

Can I find deals for flights from Belfast to Seattle that include hotel bookings?

How can I find direct flights from Belfast to Seattle?

Can I find deals for business class flights from Belfast to Seattle?

Travelling to a place near Seattle?

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 Belfast to Seattle

See prices for flight routes from nearby airports that may be better suited for you.

Complete your trip

Complete your trip to Seattle by adding a car hire and/or hotel booking to your travel itinerary.

Direct flights to Washington

Book a non-stop flight to one of these other cities located in Washington.

Search flights from Belfast to Seattle by cabin class

Find flights from Belfast to Seattle, based on your preferred cabin class, be it economy, premium economy, business, or first class.

Belfast and Seattle flights

Browse other Belfast and Seattle flight options. Last updated on 3 September 2026.

Popular flight searches

Check out other popular destinations found by fellow travellers in 2026

Other flights to Seattle

Explore flights to Seattle departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on 3 September 2026.

Fly with Cheapflights

How does Cheapflights help users find flights from Belfast to Seattle?

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

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

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

100% Free

Book with Flexibility

Travel Smart

Cheapest flights from Belfast to Seattle
Explore the most affordable flight options available from Belfast to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 3 September 2026.

Best flights from Belfast to Seattle
Discover carefully curated flight deals from Belfast to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 3 September 2026.

Last-minute flights from Belfast to Seattle
Discover last-minute flight deals from Belfast to Seattle. Data last updated 3 September 2026 and is based on user searches.