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Cheap flights from Seattle to Belfast from $400

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Belfast departing on 9/8. 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

Logo
3:45 pm - 10:25 pmSEA-BFS
22h 40m2 stops
Logo
6:00 am - 6:00 pmBFS-SEA
43h 00m2 stops
$538
Find Deal
Sun, Oct 19 - Thu, Oct 30
Logo
7:00 pm - 8:25 pmSEA-BHD
17h 25m2 stops
Logo
7:25 am - 6:00 pmBHD-SEA
17h 35m2 stops
$637
Find Deal
Sun, Oct 19 - Thu, Oct 30
Logo
7:00 pm - 8:25 pmSEA-BHD
17h 25m2 stops
Logo
7:00 am - 8:40 pmBHD-SEA
21h 40m2 stops
$689
Find Deal
Sat, Oct 4 - Sat, Oct 11
British Airways Logo
8:20 pm - 5:40 pmSEA-BHD
13h 20m1 stop
British Airways Logo
9:05 am - 5:55 pmBHD-SEA
15h 50m1 stop
$720British Airways
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Sun, Oct 19 - Thu, Oct 30
British Airways Logo
10:39 am - 11:30 amSEA-BHD
16h 51m2 stops
British Airways Logo
6:35 am - 5:55 pmBHD-SEA
18h 20m1 stop
$724British Airways
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Sun, Oct 19 - Thu, Oct 30
Virgin Atlantic Logo
7:20 am - 4:50 pmSEA-BHD
25h 30m2 stops
Virgin Atlantic Logo
5:20 pm - 11:50 amBHD-SEA
26h 30m1 stop
$941Virgin Atlantic
Find Deal
Wed, Dec 3 - Sun, Dec 7
Virgin Atlantic Logo
7:20 am - 4:50 pmSEA-BHD
25h 30m2 stops
Virgin Atlantic Logo
6:30 am - 2:45 pmBHD-SEA
16h 15m2 stops
$951Virgin Atlantic
Find Deal
Wed, Dec 3 - Sun, Dec 7
American Airlines Logo
1:23 am - 10:15 amSEA-BHD
24h 52m2 stops
American Airlines Logo
9:10 am - 6:20 pmBHD-SEA
17h 10m2 stops
$982American Airlines
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Tue, Dec 2 - Sun, Dec 7
KLM Logo
11:15 am - 4:50 pmSEA-BHD
21h 35m2 stops
KLM Logo
6:30 am - 11:50 amBHD-SEA
13h 20m1 stop
$993KLM
Find Deal
Wed, Dec 3 - Sun, Dec 7
KLM Logo
11:15 am - 4:50 pmSEA-BHD
21h 35m2 stops
KLM Logo
6:30 am - 11:50 amBHD-SEA
13h 20m1 stop
$994KLM
Find Deal
Wed, Dec 3 - Sun, Dec 7

Virgin Atlantic flights from Seattle to Belfast

Our best Virgin Atlantic deals on Seattle to Belfast flight tickets
Virgin Atlantic
Dec 3
SEA7:20 amSeattle/Tacoma Intl
25h 30m
2 stops
BHD4:50 pmBelfast City
Dec 7
BHD5:20 pmBelfast City
26h 30m
1 stop
SEA11:50 amSeattle/Tacoma Intl
$941
Find similar
Virgin Atlantic
Dec 3
SEA7:20 amSeattle/Tacoma Intl
25h 30m
2 stops
BHD4:50 pmBelfast City
Dec 7
BHD6:30 amBelfast City
16h 15m
2 stops
SEA2:45 pmSeattle/Tacoma Intl
$951
Find similar

British Airways flights from Seattle to Belfast

Our best British Airways deals on Seattle to Belfast flight tickets
British Airways
Oct 19
SEA8:20 pmSeattle/Tacoma Intl
13h 20m
1 stop
BHD5:40 pmBelfast City
Oct 30
BHD9:05 amBelfast City
15h 50m
1 stop
SEA5:55 pmSeattle/Tacoma Intl
$720
Find similar
British Airways
Oct 19
SEA10:39 amSeattle/Tacoma Intl
16h 51m
2 stops
BHD11:30 amBelfast City
Oct 30
BHD6:35 amBelfast City
18h 20m
1 stop
SEA5:55 pmSeattle/Tacoma Intl
$724
Find similar
British Airways
Oct 29
SEA7:50 pmSeattle/Tacoma Intl
13h 45m
1 stop
BHD4:35 pmBelfast City
Nov 5
BHD11:25 amBelfast City
13h 30m
1 stop
SEA4:55 pmSeattle/Tacoma Intl
$747
Find similar

momondo 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, momondo users made 832,500 searches. Data last updated August 6, 2025.
Use the filters below to find and compare flights from Seattle to Belfast that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Sun 10/19

3:45 pm-10:25 pm

2 stops22h 40m

Belfast Intl

Thu 10/30

6:00 am-6:00 pm

2 stops43h 00m

$538

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sun 10/19

7:00 pm-8:25 pm

2 stops17h 25m

Belfast City

Thu 10/30

7:25 am-6:00 pm

2 stops17h 35m

$637

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sat 10/4

7:00 pm-8:25 pm

2 stops17h 25m

Belfast City

Sat 10/11

7:00 am-8:40 pm

2 stops21h 40m

$689

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sun 10/19

8:20 pm-5:40 pm

1 stop13h 20m

Belfast City

Thu 10/30

9:05 am-5:55 pm

1 stop15h 50m

$720

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Sun 10/19

10:39 am-11:30 am

2 stops16h 51m

Belfast City

Thu 10/30

6:35 am-5:55 pm

1 stop18h 20m

$724

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 12/3

7:20 am-4:50 pm

2 stops25h 30m

Belfast City

Sun 12/7

5:20 pm-11:50 am

1 stop26h 30m

$941

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 12/3

7:20 am-4:50 pm

2 stops25h 30m

Belfast City

Sun 12/7

6:30 am-2:45 pm

2 stops16h 15m

$951

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Tue 12/2

1:23 am-10:15 am

2 stops24h 52m

Belfast City

Sun 12/7

9:10 am-6:20 pm

2 stops17h 10m

$982

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 12/3

11:15 am-4:50 pm

2 stops21h 35m

Belfast City

Sun 12/7

6:30 am-11:50 am

1 stop13h 20m

$993

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

Wed 12/3

11:15 am-4:50 pm

2 stops21h 35m

Belfast City

Sun 12/7

6:30 am-11:50 am

1 stop13h 20m

$994

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 14 resultsSorted by cheapest first
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See travel insights to Belfast from

How to get the cheapest flight ticket from Seattle to Belfast

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest day to depart on your flight to Belfast?

The cheapest day to depart from Seattle to Belfast is on a Tuesday when prices can be found for as low as $724. When flying out on a Wednesday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to Belfast for around $1,208.

What is the cheapest time of day to depart on your flight to Belfast?

Our data shows that the cheapest Seattle to Belfast flights are usually those with departure times at noon. Our users have found flights to Belfast at noon for as low as $794. Try not to purchase tickets in the afternoon because they tend to be around $1,000. Of course, these prices can vary depending on the time of year and what airport you fly to.

Cheap Seattle to Belfast flight deals and tips

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

Best Price Found

$400

Fastest flight time

12h 55m

Direct flights

None

Airports in Belfast

2 airports
The best one-way flight to Belfast from Seattle in the past 72 hours is $400. The best round-trip flight deal from Seattle to Belfast found on momondo in the last 72 hours is $538.
The fastest flight from Seattle to Belfast takes 12h 55m
There are no direct flights from Seattle to Belfast. Popular non-direct routes for this connection are Seattle/Tacoma Intl Airport - Belfast Intl Airport and Seattle/Tacoma Intl Airport - Belfast City Airport.
There are 2 airports near Belfast: Belfast Intl (BFS), Belfast City (BHD)
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  • How far is Seattle/Tacoma Intl to Belfast by plane?

    Belfast is 4463.0 mi away from Seattle/Tacoma Intl. In terms of flight time, this usually takes a little over 12h 55m.

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

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

  • How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Belfast?

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

    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.

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

    The travel and health documents required for your trip to Belfast 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. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

Best airlines flying from Seattle to Belfast

Compare and see reviews for airlines that fly from Seattle to Belfast with momondo
Airline
Rating
Free Cancellation
Price
British AirwaysPriceFrom $519Free CancellationRating
6.6
7,245 reviews
Search British Airways flights

Why use momondo?

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

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Seattle to Belfast. Millions of users trust and use momondo every year so you are in good hands.

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

Yes. momondo enables you to select and highlight flights to Belfast from Seattle with this policy.

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

momondo provides multiple filters to help you find the best flight to Belfast from Seattle. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

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.

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Find better results for your trip to the United Kingdom

Fly into one of these airports located in Belfast

Airports listed have a maximum distance of 12.2 mi from Belfast
Belfast Intl Airport
Belfast City Airport