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Belfast Intl

$346+ Cheap flights from Seattle (SEA) to Belfast Intl (BFS)

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 3/25. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BFS
Feb 25 — Mar 41
Wed 2/25
Wed 3/4
1 adult, Economy
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Cheap flight deals from Seattle to Belfast Intl

Cheapest flights from Seattle to Belfast Intl
Explore the most affordable flight options available from Seattle to Belfast Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 26, 2026.

This Mytrip deal was found by Cheapflights users on 1/26. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/123:00 pm
SEA
-
BFS
2 stops22h 25m
Multiple Airlines
Thu 3/199:05 am
BFS
-
SEA
2 stops35h 05m
Multiple Airlines
Deal found 1/26$820
This Mytrip deal was found by Cheapflights users on 1/26. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/12:35 pm
SEA
-
BFS
2 stops21h 45m
Multiple Airlines
Fri 2/135:45 am
BFS
-
SEA
3 stops41h 55m
Multiple Airlines
Deal found 1/26$1,002

Find flight deals from Seattle to Belfast Intl

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Belfast Intl (BFS). 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 January 26, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$820
(Mytrip)

One-way from

$346
(Kiwi.com)

Popular in

December

Cheapest in

April

Average price

$951
Provider with most accurate pricing for Seattle/Tacoma Intl-Belfast Intl flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Belfast Intl flights.
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From Seattle/Tacoma Intl to Belfast Intl
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One-way flight from Seattle/Tacoma Intl to Belfast Intl
Search Deals
Highest demand for flights based on searches. 10% potential increase in price ($121 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($60 potential savings vs. average RT price).
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Average for round-trip flights in January 2026
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Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to Belfast Intl 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 January 26, 2026.
Use the filters below to find and compare flights from Seattle to Belfast Intl Airport that are best for you.

Fly from

Seattle

Fly to

Belfast Intl

Route

Depart

Return

Price

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Thu 3/12

3:00 pm-8:25 pm

2 stops22h 25m

Belfast Intl

Thu 3/19

9:05 am-1:10 pm

2 stops35h 05m

$820

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Wed 3/25

3:35 pm-4:10 pm

2 stops17h 35m

$346

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/25

Compare providers for flights from Seattle to Belfast Intl

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Belfast Intl in January.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*3 stars
OvagoPrice Accuracy2 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Seattle-Belfast Intl Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Belfast Intl Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Belfast Intl Airport flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Belfast Intl Airport flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-Belfast Intl Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Seattle to Belfast Intl

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

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

Related info for your journey

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

    Located just 11.4 mi from the city center, Seattle/Tacoma Intl is the airport most travelers will use when flying to Belfast Intl from Seattle. Booking flights from Seattle/Tacoma Intl (SEA) to Belfast Intl should be relatively easy as there are 0 daily outbound flights to Belfast Intl from 0 different airlines.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Seattle to Belfast Intl 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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