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Belfast Intl

$312+ 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 1/15. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BFS
Jan 11 — Jan 181
Sun 1/11
Sun 1/18
1 adult, Economy
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Cheap flight deals from Seattle to Belfast Intl

Best flights from Seattle to Belfast Intl
Discover carefully curated flight deals from Seattle to Belfast Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated December 12, 2025.

This Mytrip deal was found by Cheapflights users on 12/10. 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.
Sat 1/242:35 pmSEA - BFS
2 stops19h 05mMultiple Airlines
Sat 1/318:10 amBFS - SEA
2 stops16h 50mMultiple Airlines
Deal found 12/10$751

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 December 12, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

AranGrant
3 stars

Round-trip from

$751
(Mytrip)

One-way from

$312
(Trip.com)

Popular in

December

Cheapest in

April

Average price

$1,583
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. 11% potential increase in price ($128 potential increase over avg. RT price).
Search Deals
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 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 December 12, 2025.
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

Sat 1/24

2:35 pm-5:40 pm

2 stops19h 05m

Belfast Intl

Sat 1/31

8:10 am-5:00 pm

2 stops16h 50m

$751

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Thu 1/15

2:35 pm-10:35 pm

2 stops24h 00m

$312

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/11

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 December.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*1 star
AranGrantPrice 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 AranGrant the most. AranGrant 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.

Reviews of airlines servicing Belfast Intl

Get insights into the airlines that provide service to Belfast Intl. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Belfast Intl. Reviews last updated December 12, 2025.
Read through reviews of airlines operating flights from Seattle to Belfast Intl Airport, such as British Airways. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
British Airways
6.7
Okay
7,571 reviews

Entertainment

6.4

Overall

6.7

Comfort

6.7

Boarding

6.9

Crew

7.6

Food

6.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2025

IAD - LHR

The plane had to load and unload passengers not through a jet way but out on the tarmac at Heathrow. The steps were steep. We weren't expecting to have to carry our luggage up and down stairs.
British Airways
6.7
Okay
7,571 reviews
British Airways
6.7
Okay
7,571 reviews

Entertainment

6.4

Overall

6.7

Comfort

6.7

Boarding

6.9

Crew

7.6

Food

6.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2025

IAD - LHR

The plane had to load and unload passengers not through a jet way but out on the tarmac at Heathrow. The steps were steep. We weren't expecting to have to carry our luggage up and down stairs.

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 1 airline.

  • What is the cheapest airline to fly from Seattle to Belfast Intl Airport round-trip?

    According to our current data, British Airways ($737), offers the cheapest pricing from Seattle to Belfast Intl Airport. You may be able to fly from Seattle to Belfast Intl Airport for 25% less than the average price by searching for this airline.

  • 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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Alternative routes for Seattle to Belfast Intl

See prices for flight routes from nearby airports that may be better suited for you.
Seattle to Belfast City flights
Portland to Belfast Intl flights
Portland to Belfast City flights

Top airline flying from Seattle to Belfast Intl

Discover the top airline that operate flights from Seattle to Belfast Intl. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated December 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$737Average$866FlexibilityNo cancel feeOn-time70%

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