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$432+ 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 8/8. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BHD
Aug 4 — Aug 111
Mon 8/4
Mon 8/11
1 adult, Economy
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Cheap 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 July 30, 2025.

Round-trip from

$707
(Trip.com)

One-way from

$432
(Kiwi.com)

Popular in

July

Cheapest in

March

Average price

$1,145
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 ($123 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 July 2025
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Find flight deals from Seattle to Belfast

Cheapest flights from Seattle to Belfast
Explore the most affordable flight options available from Seattle to Belfast. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 30, 2025.

This Trip.com deal was found by Cheapflights users on 7/29. 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.
Sun 9/77:00 pmSEA - BFS
2 stops20h 10mMultiple Airlines
Tue 9/237:00 amBFS - SEA
2 stops21h 40mMultiple Airlines
Deal found 7/29$707
This oojo deal was found by Cheapflights users on 7/30. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/103:00 pmSEA - BHD
2 stops16h 35mBritish Airways
Mon 9/157:30 pmBHD - SEA
1 stop23h 40mBritish Airways
Deal found 7/30$743
This Mytrip deal was found by Cheapflights users on 7/29. 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.
Wed 8/273:45 pmSEA - BHD
2 stops20h 50mMultiple Airlines
Wed 9/37:05 amBHD - SEA
2 stops21h 35mMultiple Airlines
Deal found 7/29$806
This Delta deal was found by Cheapflights users on 7/29. 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.
Sun 9/71:55 pmSEA - BHD
1 stop19h 00mDelta
Tue 9/236:30 amBHD - SEA
2 stops25h 12mDelta
Deal found 7/29$828
This Mytrip deal was found by Cheapflights users on 7/29. 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 9/77:35 pmSEA - BHD
2 stops30h 10mAer Lingus
Tue 9/239:50 amBHD - SEA
2 stops16h 00mAer Lingus
Deal found 7/29$859
This KLM deal was found by Cheapflights users on 7/29. 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.
Sun 8/245:40 pmSEA - BHD
1 stop19h 35mKLM
Thu 9/46:40 amBHD - SEA
1 stop17h 25mKLM
Deal found 7/29$954
This American Airlines deal was found by Cheapflights users on 7/29. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/2710:35 amSEA - BHD
2 stops17h 20mAmerican Airlines
Wed 9/31:50 pmBHD - SEA
1 stop12h 30mAmerican Airlines
Deal found 7/29$1,006
This Virgin Atlantic deal was found by Cheapflights users on 7/28. 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 Virgin Atlantic is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/236:00 amSEA - BHD
2 stops26h 50mVirgin Atlantic
Sun 1/115:20 pmBHD - SEA
1 stop26h 30mVirgin Atlantic
Deal found 7/28$1,496

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 July 30, 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 - BFS

SEABFS

Seattle/Tacoma Intl

Sun 9/7

7:00 pm-11:10 pm

2 stops20h 10m

Belfast Intl

Tue 9/23

7:00 am-8:40 pm

2 stops21h 40m

$707

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 9/10

3:00 pm-3:35 pm

2 stops16h 35m

Belfast City

Mon 9/15

7:30 pm-11:10 am

1 stop23h 40m

$743

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 8/27

3:45 pm-8:35 pm

2 stops20h 50m

Belfast City

Wed 9/3

7:05 am-8:40 pm

2 stops21h 35m

$806

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sun 9/7

1:55 pm-4:55 pm

1 stop19h 00m

Belfast City

Tue 9/23

6:30 am-11:42 pm

2 stops25h 12m

$828

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sun 9/7

7:35 pm-9:45 am

2 stops30h 10m

Belfast City

Tue 9/23

9:50 am-5:50 pm

2 stops16h 00m

$859

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sun 8/24

5:40 pm-9:15 pm

1 stop19h 35m

Belfast City

Thu 9/4

6:40 am-4:05 pm

1 stop17h 25m

$954

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 8/27

10:35 am-11:55 am

2 stops17h 20m

Belfast City

Wed 9/3

1:50 pm-6:20 pm

1 stop12h 30m

$1,006

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Tue 12/23

6:00 am-4:50 pm

2 stops26h 50m

Belfast City

Sun 1/11

5:20 pm-11:50 am

1 stop26h 30m

$1,496

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Fri 8/8

8:01 pm-7:45 am

3 stops51h 44m

$432

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Fri 8/8

8:01 pm-8:10 am

3 stops52h 09m

$447

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/28

Showing 1-10 of 12 results
1
2

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 July 30, 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 23% on your trip compared to booking a flight at noon.

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

Reviews of airlines servicing Belfast

Get insights into the airlines that provide service to Belfast. 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. Reviews last updated July 30, 2025.
Read reviews from past customers who have flown Delta, KLM, and Virgin Atlantic from Seattle to Belfast. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,980 reviews

Crew

8.5

Entertainment

7.9

Boarding

8.2

Food

7.3

Comfort

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Delta
8.0
Very good
7,980 reviews
Delta
8.0
Very good
7,980 reviews

Crew

8.5

Entertainment

7.9

Boarding

8.2

Food

7.3

Comfort

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
KLM
7.8
Good
1,383 reviews
Delta
8.0
Very good
7,980 reviews

Crew

8.5

Entertainment

7.9

Boarding

8.2

Food

7.3

Comfort

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Virgin Atlantic
7.4
Good
655 reviews
Delta
8.0
Very good
7,980 reviews

Crew

8.5

Entertainment

7.9

Boarding

8.2

Food

7.3

Comfort

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
American Airlines
7.2
Good
10,000 reviews
Delta
8.0
Very good
7,980 reviews

Crew

8.5

Entertainment

7.9

Boarding

8.2

Food

7.3

Comfort

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Aer Lingus
7.1
Good
1,191 reviews
Delta
8.0
Very good
7,980 reviews

Crew

8.5

Entertainment

7.9

Boarding

8.2

Food

7.3

Comfort

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

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 1 airline.

  • What are the cheapest airlines flying from Seattle to Belfast round-trip?

    Flying on British Airways is currently your cheapest option to Belfast, with prices starting at $743. Additional round-trip tickets that might be worth considering are offered by Delta and Aer Lingus, with the lowest prices starting at $828 and $859, respectively. British Airways is 17% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest airlines to fly from Seattle to Belfast one-way?

    The cheapest airlines for a one-way flight from Seattle to Belfast are British Airways ($478), American Airlines ($482), and KLM ($508).

  • 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.

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

    Currently, February is the cheapest month in which you can book a flight from Seattle to Belfast (average of $657). Flying from Seattle to Belfast 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

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

Top airline flying from Seattle to Belfast

Discover the top airline that operate flights from Seattle to Belfast. 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 July 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$519Average$866FlexibilityNo cancel feeOn-time70%

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