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Belfast Intl

$920+ 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 6/4. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BFS
May 24 — May 311
Sun 5/24
Sun 5/31
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 April 24, 2026.

This Mytrip deal was found by Cheapflights users on 4/20. 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 6/43:40 pm
SEA
-
BFS
3 stops24h 15m
Multiple Airlines
Thu 6/116:40 am
BFS
-
SEA
3 stops24h 00m
Multiple Airlines
Deal found 4/20$920
This Mytrip deal was found by Cheapflights users on 4/20. 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 6/43:40 pm
SEA
-
BFS
3 stops20h 40m
Multiple Airlines
Fri 6/127:05 am
BFS
-
SEA
3 stops34h 35m
Multiple Airlines
Deal found 4/20$1,006
This Trip.com deal was found by Cheapflights users on 4/20. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/246:10 pm
SEA
-
BFS
2 stops20h 15m
Multiple Airlines
Mon 8/316:10 am
BFS
-
SEA
2 stops18h 00m
Multiple Airlines
Deal found 4/20$1,013
This Mytrip deal was found by Cheapflights users on 4/21. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/63:40 pm
SEA
-
BFS
2 stops23h 45m
Multiple Airlines
Sat 6/136:55 am
BFS
-
SEA
3 stops19h 35m
Multiple Airlines
Deal found 4/21$1,062
This Mytrip deal was found by Cheapflights users on 4/20. 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.
Fri 6/53:40 pm
SEA
-
BFS
3 stops23h 40m
Multiple Airlines
Fri 6/126:05 am
BFS
-
SEA
2 stops22h 35m
Multiple Airlines
Deal found 4/20$1,069
This Mytrip deal was found by Cheapflights users on 4/20. 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.
Mon 9/217:00 pm
SEA
-
BFS
2 stops17h 40m
Multiple Airlines
Sat 10/311:10 am
BFS
-
SEA
3 stops38h 05m
Multiple Airlines
Deal found 4/20$1,075
This Mytrip deal was found by Cheapflights users on 4/22. 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 6/73:40 pm
SEA
-
BFS
3 stops22h 15m
Multiple Airlines
Sun 6/149:55 am
BFS
-
SEA
2 stops33h 50m
Multiple Airlines
Deal found 4/22$1,084
This Kiwi.com deal was found by Cheapflights users on 4/20. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/47:10 pm
SEA
-
BFS
2 stops30h 25m
Multiple Airlines
Tue 9/158:50 am
BFS
-
SEA
1 stop18h 05m
Multiple Airlines
Deal found 4/20$1,091

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 April 24, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$920
(Mytrip)

Popular in

December

Cheapest in

October

Average price

$1,078
Provider with most accurate pricing for Seattle/Tacoma Intl-Belfast Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Belfast Intl flights.
Search Deals
From Seattle/Tacoma Intl to Belfast Intl
Search Deals
Highest demand for flights based on searches. 12% potential increase in price ($152 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($60 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in April 2026
Search Deals

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 April 24, 2026.
Use the filters below to find and compare flights from Seattle to Belfast Intl Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Thu 6/4

3:40 pm-8:20 pm

3 stops20h 40m

Belfast Intl

Fri 6/12

7:05 am-9:40 am

3 stops34h 35m

$1,006

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Mon 8/24

6:10 pm-10:25 pm

2 stops20h 15m

Belfast Intl

Mon 8/31

6:10 am-4:10 pm

2 stops18h 00m

$1,013

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Sat 6/6

3:40 pm-11:25 pm

2 stops23h 45m

Belfast Intl

Sat 6/13

6:55 am-6:30 pm

3 stops19h 35m

$1,062

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Fri 9/4

7:10 pm-9:35 am

2 stops30h 25m

Belfast Intl

Tue 9/15

8:50 am-6:55 pm

1 stop18h 05m

$1,091

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Sun 6/7

3:40 pm-9:30 pm

2 stops21h 50m

Belfast Intl

Sun 6/14

7:10 am-5:55 pm

2 stops18h 45m

$1,162
Quickest round-trip

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Thu 9/10

9:45 pm-11:00 pm

1 stop17h 15m

Belfast Intl

Thu 9/24

9:15 am-8:40 pm

2 stops19h 25m

$1,231

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Wed 9/9

7:10 pm-10:20 pm

2 stops19h 10m

Belfast Intl

Tue 9/22

8:15 pm-6:55 pm

1 stop30h 40m

$1,268

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/20

Sorted by cheapest first

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 April.
ProviderPrice AccuracyTrust Score*
OvagoPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 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?

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 April 24, 2026.
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
7,910 reviews

Entertainment

6.4

Crew

7.7

Overall

6.7

Boarding

6.9

Comfort

6.8

Food

6.4

Reviews

1 / 20
10.0
Excellent

Viorica,Mar 2026

PHX - LHR

The food lately is just from poor to very poor. I bealeave that you can serve less quantities for more quality food. Exemple : at breakfast : omlete and vegetarian omlete ....I beleave with less work less personel could be provide some hummus and carrots and some boiled egss plus whatever snacks or drinks you wish....... Thank you in advance
British Airways
6.7
Okay
7,910 reviews
British Airways
6.7
Okay
7,910 reviews

Entertainment

6.4

Crew

7.7

Overall

6.7

Boarding

6.9

Comfort

6.8

Food

6.4

Reviews

1 / 20
10.0
Excellent

Viorica,Mar 2026

PHX - LHR

The food lately is just from poor to very poor. I bealeave that you can serve less quantities for more quality food. Exemple : at breakfast : omlete and vegetarian omlete ....I beleave with less work less personel could be provide some hummus and carrots and some boiled egss plus whatever snacks or drinks you wish....... Thank you in advance

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 ($776), 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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Other flights to Belfast Intl

Explore flights to Belfast Intl departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on April 24, 2026.
Belfast Intl Airport to Edinburgh flights
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Belfast Intl Airport to Edinburgh 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 April 24, 2026.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$776Average$1,056FlexibilityNo cancel feeOn-time70%

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