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Belfast Intl

$807+ Cheap flights from Seattle (SEA) to Belfast Intl (BFS)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/25. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BFS
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
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Cheap 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 September 11, 2025.

Round-trip from

$807
(Mytrip)

Popular in

July

Cheapest in

March

Average price

$993
From Seattle/Tacoma Intl to Belfast Intl
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Highest demand for flights based on searches. 8% potential increase in price ($83 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($24 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find 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 September 11, 2025.

This Mytrip deal was found by Cheapflights users on 9/10. 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 10/258:40 amSEA - BFS
3 stops30h 40mMultiple Airlines
Sat 11/110:25 pmBFS - SEA
3 stops47h 55mMultiple Airlines
Deal found 9/10$807
This Mytrip deal was found by Cheapflights users on 9/10. 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.
Thu 10/91:50 pmSEA - BFS
3 stops20h 25mMultiple Airlines
Tue 10/148:10 amBFS - SEA
3 stops38h 55mMultiple Airlines
Deal found 9/10$929

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 September 11, 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 10/25

8:40 am-11:20 pm

3 stops30h 40m

Belfast Intl

Sat 11/1

10:25 pm-3:20 pm

3 stops47h 55m

$807

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Thu 10/9

1:50 pm-6:15 pm

3 stops20h 25m

Belfast Intl

Tue 10/14

8:10 am-3:05 pm

3 stops38h 55m

$929

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/10

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 September 11, 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
7,361 reviews

Entertainment

6.4

Food

6.3

Overall

6.7

Comfort

6.7

Crew

7.6

Boarding

6.9

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
7,361 reviews
British Airways
6.7
Okay
7,361 reviews

Entertainment

6.4

Food

6.3

Overall

6.7

Comfort

6.7

Crew

7.6

Boarding

6.9

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 19% 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.

  • What is the cheapest month to book a flight from Seattle to Belfast Intl Airport?

    Currently, February is the cheapest month in which you can book a flight from Seattle to Belfast Intl Airport (average of $657). Flying from Seattle to Belfast Intl Airport in June is currently the most expensive (average of $1,189). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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 September 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$737Average$951FlexibilityNo cancel feeOn-time70%

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