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$408+ 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 6/20. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BHD
May 5 — May 121
Mon 5/5
Mon 5/12
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 April 30, 2025.

Round-trip from

$832
(Mytrip)

One-way from

$408
(Kiwi.com)

Popular in

June

Cheapest in

October

Average price

$785
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. 18% potential increase in price ($209 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($51 potential savings vs. average RT price).
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Average for round-trip flights in April 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 April 30, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 4/29. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/287:50 pmSEA - BHD
1 stop15h 50mBritish Airways
Tue 11/46:35 amBHD - SEA
1 stop12h 45mBritish Airways
Deal found 4/29$763
This American Airlines deal was found by Cheapflights users on 4/29. 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.
Tue 10/2810:46 amSEA - BHD
2 stops16h 44mAmerican Airlines
Tue 11/46:35 amBHD - SEA
1 stop12h 45mAmerican Airlines
Deal found 4/29$770
This Mytrip deal was found by Cheapflights users on 4/28. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/1110:00 amSEA - BFS
3 stops24h 35mMultiple Airlines
Wed 6/183:05 pmBFS - SEA
3 stops39h 11mMultiple Airlines
Deal found 4/28$832
This Delta deal was found by Cheapflights users on 4/28. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/46:07 pmSEA - BHD
1 stop19h 08mDelta
Mon 5/125:25 pmBHD - SEA
1 stop26h 15mDelta
Deal found 4/28$887
This Trip.com deal was found by Cheapflights users on 4/29. 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.
Fri 5/27:00 pmSEA - BHD
2 stops17h 25mMultiple Airlines
Sun 5/117:05 amBHD - SEA
2 stops21h 35mMultiple Airlines
Deal found 4/29$938
This Cheapflightsfares deal was found by Cheapflights users on 4/28. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/37:35 pmSEA - BHD
2 stops15h 50mAer Lingus
Tue 6/107:00 amBHD - SEA
2 stops18h 50mAer Lingus
Deal found 4/28$1,010
This KLM deal was found by Cheapflights users on 4/29. 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.
Fri 5/25:12 pmSEA - BHD
2 stops15h 43mKLM
Sat 5/105:25 pmBHD - SEA
1 stop30h 32mKLM
Deal found 4/29$1,036

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 April 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

Wed 6/11

10:00 am-6:35 pm

3 stops24h 35m

Belfast Intl

Wed 6/18

3:05 pm-10:16 pm

3 stops39h 11m

$832

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Tue 6/3

7:35 pm-7:25 pm

2 stops15h 50m

Belfast City

Tue 6/10

7:00 am-5:50 pm

2 stops18h 50m

$1,010

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Thu 6/12

7:05 am-8:55 pm

3 stops29h 50m

Belfast City

Thu 6/19

7:05 am-3:03 pm

3 stops39h 58m

$1,053

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Tue 6/3

8:20 pm-7:25 pm

1 stop15h 05m

Belfast City

Tue 6/10

6:35 am-11:10 am

1 stop12h 35m

$1,116

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sun 6/29

1:55 pm-4:55 pm

1 stop19h 00m

Belfast City

Thu 7/10

5:25 pm-11:35 am

1 stop26h 10m

$3,754

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 6/25

9:50 am-4:55 pm

2 stops23h 05m

Belfast City

Sun 7/6

6:30 am-3:50 pm

1 stop17h 20m

$4,478

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Fri 6/20

5:54 pm-7:50 am

3 stops53h 56m

$408

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Fri 6/20

5:54 pm-9:15 am

3 stops55h 21m

$446

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Tue 6/3

8:20 pm-5:30 pm

1 stop13h 10m

$752

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Fri 6/20

1:55 pm-4:55 pm

1 stop19h 00m

$858

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/27

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 April 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.

Rainfall in Belfast by month

Plan your trip to Belfast by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Belfast ranges from 2.0 - 3.5 inches per month. October is typically the wettest month, when rainfall can reach 3.5 in. April is typically the driest time to visit Belfast when rainfall is around 2.0 in.

Temperature in Belfast by month

Plan your trip to Belfast by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Belfast, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 60.8 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 41.0 F).

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 April 30, 2025.
Delta
8.0
Very good
7,929 reviews

Food

7.3

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Delta
8.0
Very good
7,929 reviews
Delta
8.0
Very good
7,929 reviews

Food

7.3

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
KLM
7.8
Good
1,334 reviews
Delta
8.0
Very good
7,929 reviews

Food

7.3

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Aer Lingus
7.0
Good
1,076 reviews
Delta
8.0
Very good
7,929 reviews

Food

7.3

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
British Airways
6.6
Okay
6,835 reviews
Delta
8.0
Very good
7,929 reviews

Food

7.3

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

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 Aer Lingus is currently your cheapest option to Belfast, with prices starting at $1,010. Additional round-trip tickets that might be worth considering are offered by British Airways and KLM, with the lowest prices starting at $1,116 and $3,754, respectively.

  • 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

Browse thousands of different options on Cheapflights for your next trip

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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 April 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$544Average$891FlexibilityNo cancel feeOn-time70%

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