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Cheap flights from Seattle to Belfast from $829

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Belfast departing on 3/9. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Find the cheapest flights from Seattle to Belfast

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
3:35 pm - 8:15 pm
SEA
-
BFS
21h 40m
2 stops
Multiple Airlines Logo
10:45 pm - 4:40 pm
BFS
-
SEA
24h 55m
3 stops
$829Multiple Airlines
Mon, Mar 9 - Sun, Mar 15
Multiple Airlines Logo
3:35 pm - 9:30 pm
SEA
-
BFS
22h 55m
3 stops
Multiple Airlines Logo
10:45 pm - 4:40 pm
BFS
-
SEA
24h 55m
3 stops
$853Multiple Airlines
Mon, Mar 9 - Sun, Mar 15
Multiple Airlines Logo
3:35 pm - 8:15 pm
SEA
-
BFS
21h 40m
2 stops
Multiple Airlines Logo
11:05 pm - 1:10 pm
BFS
-
SEA
21h 05m
2 stops
$885Multiple Airlines
Mon, Mar 9 - Sun, Mar 15
Multiple Airlines Logo
4:10 pm - 10:50 pm
SEA
-
BFS
23h 40m
3 stops
Multiple Airlines Logo
6:25 pm - 6:00 pm
BFS
-
SEA
30h 35m
3 stops
$1,127Multiple Airlines
Wed, Mar 18 - Wed, Mar 25
Multiple Airlines Logo
4:10 pm - 10:50 pm
SEA
-
BFS
23h 40m
3 stops
Multiple Airlines Logo
7:20 am - 6:00 pm
BFS
-
SEA
17h 40m
2 stops
$1,145Multiple Airlines
Wed, Mar 18 - Wed, Mar 25
Multiple Airlines Logo
4:10 pm - 8:20 pm
SEA
-
BFS
21h 10m
2 stops
Multiple Airlines Logo
7:20 am - 6:00 pm
BFS
-
SEA
17h 40m
2 stops
$1,197Multiple Airlines
Wed, Mar 18 - Wed, Mar 25
Multiple Airlines Logo
7:30 am - 8:55 pm
SEA
-
BFS
29h 25m
3 stops
Multiple Airlines Logo
6:10 am - 8:40 pm
BFS
-
SEA
22h 30m
2 stops
$1,207Multiple Airlines
Mon, Jun 22 - Thu, Jul 2
Multiple Airlines Logo
7:30 am - 8:55 pm
SEA
-
BFS
29h 25m
3 stops
Multiple Airlines Logo
7:40 pm - 8:40 pm
BFS
-
SEA
33h 00m
3 stops
$1,212Multiple Airlines
Mon, Jun 22 - Thu, Jul 2
Multiple Airlines Logo
4:35 pm - 12:05 am
SEA
-
BFS
23h 30m
2 stops
Multiple Airlines Logo
9:15 am - 8:40 pm
BFS
-
SEA
19h 25m
2 stops
$1,259Multiple Airlines
Mon, Jun 22 - Thu, Jul 2
Multiple Airlines Logo
9:45 pm - 11:20 pm
SEA
-
BFS
17h 35m
1 stop
Multiple Airlines Logo
9:15 am - 8:40 pm
BFS
-
SEA
19h 25m
2 stops
$1,513Multiple Airlines
Mon, Jun 22 - Thu, Jul 2

momondo Fare Finder

 
Customize your flight search to find flights from Seattle to Belfast Intl Airport 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, momondo users made 832,500 searches. Data last updated February 3, 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

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Mon 3/9

3:35 pm-8:15 pm

2 stops21h 40m

Belfast Intl

Sun 3/15

10:45 pm-4:40 pm

3 stops24h 55m

$829

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Mon 3/9

3:35 pm-9:30 pm

3 stops22h 55m

Belfast Intl

Sun 3/15

10:45 pm-4:40 pm

3 stops24h 55m

$853

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Mon 3/9

3:35 pm-8:15 pm

2 stops21h 40m

Belfast Intl

Sun 3/15

11:05 pm-1:10 pm

2 stops21h 05m

$885

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Wed 3/18

4:10 pm-10:50 pm

3 stops23h 40m

Belfast Intl

Wed 3/25

6:25 pm-6:00 pm

3 stops30h 35m

$1,127

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Wed 3/18

4:10 pm-10:50 pm

3 stops23h 40m

Belfast Intl

Wed 3/25

7:20 am-6:00 pm

2 stops17h 40m

$1,145

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Wed 3/18

4:10 pm-8:20 pm

2 stops21h 10m

Belfast Intl

Wed 3/25

7:20 am-6:00 pm

2 stops17h 40m

$1,197

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Mon 6/22

7:30 am-8:55 pm

3 stops29h 25m

Belfast Intl

Thu 7/2

6:10 am-8:40 pm

2 stops22h 30m

$1,207

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Mon 6/22

7:30 am-8:55 pm

3 stops29h 25m

Belfast Intl

Thu 7/2

7:40 pm-8:40 pm

3 stops33h 00m

$1,212

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Mon 6/22

4:35 pm-12:05 am

2 stops23h 30m

Belfast Intl

Thu 7/2

9:15 am-8:40 pm

2 stops19h 25m

$1,259

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Mon 6/22

9:45 pm-11:20 pm

1 stop17h 35m

Belfast Intl

Thu 7/2

9:15 am-8:40 pm

2 stops19h 25m

$1,513

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

When to book flights from Seattle to Belfast Intl Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Seattle to Belfast Intl Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Seattle to Belfast Intl Airport (SEA to BFS) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to Belfast Intl Airport

Fastest flight time

12h 35m

Direct flights

None
The fastest flight from Seattle to Belfast Intl Airport takes 12h 35m
There are no direct flights from Seattle to Belfast Intl Airport. There are no popular flight routes from Seattle to Belfast Intl Airport.
Search flight deals

  • How far is Seattle/Tacoma Intl to Belfast Intl by plane?

    Belfast Intl is 4452.2 mi away from Seattle/Tacoma Intl. By plane, this route typically takes 12h 35m.

  • When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Belfast Intl Airport?

    Prices for flights from Seattle/Tacoma Intl Airport to Belfast Intl Airport are refreshed on a daily basis.

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to Belfast Intl Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to Belfast Intl Airport.

  • What documentation or ID do you need to fly to Belfast Intl Airport?

    The travel and health documents required for your trip to Belfast Intl Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Belfast Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • How do I get Price Alerts for flights from Seattle to Belfast Intl Airport?

    You can take advantage of momondo’s Price Alerts by first searching for your flights to Seattle from Belfast Intl Airport. Flight offers will be shown to you in real-time. From there you can create a Price Alert by using our on-site widget.

  • How can I save money on flights from Seattle to Belfast Intl Airport with momondo?

    With “Price Forecast”, learn how soon you should book your flight in advance. Down to the day of week and time of day, our information can inform you on the ideal time to book to save on your travel. Our “Price Calendar” shows you at a quick glance when to book your travel for lower rates. By setting “Price Alerts” you can monitor changes in price and target the ideal time to book. Search for your trip destination by budget amount via our “Explore” feature. Whether you’re looking for ideas for your next travel adventure or cost-cutting tips, our “Discover” content is a great place to start.

  • How does momondo find its flight prices?

    We aggregate our prices from over 700+ competitors from airlines to OTAs. We operate in over 30 markets worldwide to show you a wide range of travel options.

Traveling to a place near Belfast?

Book flights to Belfast if you plan to visit one of these locations
Armagh
Cookstown
Ballymena
Newry
Dungannon

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to Belfast?

It is quick and easy to find Seattle to Belfast flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Belfast that suits you.

Can I find flights from Seattle to Belfast with flexible booking policies on momondo?

Flights from Seattle to Belfast with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from Seattle to Belfast?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Seattle to Belfast.

I’m not ready to book a flight from Seattle to Belfast right now. Can momondo alert me if prices change?

Yes. momondo can track prices for Seattle to Belfast flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

An easier way to manage your Belfast Intl Airport trip

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