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$214+ Cheap flights from Seattle (SEA) to Belfast

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 4/12. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BHD
Jan 22 — Jan 291
Thu 1/22
Thu 1/29
1 adult, Economy
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Cheap flight deals from Seattle to Belfast

Best flights from Seattle to Belfast
Discover carefully curated flight deals from Seattle to Belfast that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated December 23, 2025.

This Air France deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/73:05 pmSEA - BHD
1 stop17h 45mMultiple Airlines
Wed 3/185:20 pmBHD - SEA
1 stop26h 15mMultiple Airlines
Deal found 12/21$646
This Delta deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/73:05 pmSEA - BHD
1 stop21h 55mDelta
Tue 3/176:30 amBHD - SEA
1 stop13h 05mDelta
Deal found 12/21$646
This KLM deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/15:30 pmSEA - BHD
1 stop15h 25mKLM
Wed 4/85:30 pmBHD - SEA
1 stop31h 00mKLM
Deal found 12/21$660
This Delta deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/73:05 pmSEA - BHD
1 stop21h 55mDelta
Wed 3/186:30 amBHD - SEA
2 stops20h 18mDelta
Deal found 12/21$656

Find flight deals from Seattle to Belfast

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Belfast (BF1). 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 December 23, 2025.

Round-trip from

$645
(Cheapflightsfares)

One-way from

$214
(oojo)

Popular in

December

Cheapest in

April

Average price

$1,583
From Seattle/Tacoma Intl to Belfast
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One-way flight from Seattle/Tacoma Intl to Belfast
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Highest demand for flights based on searches. 11% potential increase in price ($128 potential increase over avg. RT price).
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Cheapest flight prices on average. 6% potential price decrease ($59 potential savings vs. average RT price).
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Average for round-trip flights in December 2025
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Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to Belfast 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 2,558,603 searches. Data last updated December 23, 2025.
Use the filters below to find and compare flights from Seattle to Belfast that are best for you.

Fly from

Seattle

Fly to

Belfast

Route

Depart

Return

Price

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sat 3/7

3:05 pm-4:50 pm

1 stop17h 45m

Belfast City

Wed 3/18

5:20 pm-12:35 pm

1 stop26h 15m

$646

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sat 3/7

3:05 pm-9:00 pm

1 stop21h 55m

Belfast City

Tue 3/17

6:30 am-12:35 pm

1 stop13h 05m

$646

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sat 3/7

3:05 pm-9:00 pm

1 stop21h 55m

Belfast City

Wed 3/18

6:30 am-7:48 pm

2 stops20h 18m

$656

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 4/1

5:30 pm-4:55 pm

1 stop15h 25m

Belfast City

Wed 4/8

5:30 pm-4:30 pm

1 stop31h 00m

$660

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sun 4/12

8:20 pm-8:45 pm

1 stop16h 25m

$214

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sun 4/12

7:00 am-10:30 am

2 stops19h 30m

$230

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Sun 4/12

1:35 pm-11:10 pm

2 stops25h 35m

$267

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 12/31

2:35 pm-4:20 pm

2 stops17h 45m

$1,469

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 12/31

6:50 pm-7:10 pm

1 stop16h 20m

$8,096

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/22

Best time to book a flight from Seattle to Belfast

Have a flexible travel schedule? Discover the best time to fly to Belfast 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.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Belfast

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

Find hourly flight availability from Seattle to Belfast. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 23, 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Belfast in the morning. If you’re flexible enough to do this you can expect to save up to 8% on your trip compared to booking a flight in the afternoon.

How much does it cost to fly round-trip from Seattle to Belfast?

Related info for your journey

Find useful and relevant information for your journey from Seattle to Belfast. 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 Belfast?

    If you book a flight to Belfast from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 0 flights from Seattle/Tacoma Intl to Belfast per day from 0 different airlines.

  • How long is the flight from Seattle to Belfast?

    Airlines like Delta fly from Seattle to Belfast in about 21h 55m. The time it takes to get you to your destination can typically vary by up to . The distance between Seattle and Belfast is about 4472 mi.

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

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

  • How can I find direct flights from Seattle to Belfast?

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

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

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

See more FAQs

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Alternative routes for Seattle to Belfast

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