$310 Find Cheap Flights from Seattle to Belfast

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Seattle to Belfast departing on 8/17. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Belfast

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to Belfast, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to Belfast, as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
$890
British Airways
Mon 10/5Thu 10/22
SEA - BHD • 1 stop
Cheapest one-way
$310
Multiple Airlines
Mon 8/17
SEA - BFS • 3 stops
Top airlines
Cheapest • from $890 (round-trip)
Best reviews • 6.7 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
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Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Seattle to Belfast (SEA-BHD)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Seattle to Belfast that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Seattle to Belfast

Mon, Oct 5 - Thu, Oct 22
British Airways Logo
8:20 pm - 6:45 pm
SEA
-
BHD
14h 25m
1 stop
British Airways Logo
6:30 am - 11:35 am
BHD
-
SEA
13h 05m
1 stop
$890British Airways
Mon, Oct 5 - Thu, Oct 22
British Airways Logo
8:20 pm - 6:45 pm
SEA
-
BHD
14h 25m
1 stop
British Airways Logo
12:45 pm - 6:25 pm
BHD
-
SEA
13h 40m
1 stop
$891British Airways
Tue, Sep 8 - Tue, Sep 29
British Airways Logo
1:30 pm - 6:55 pm
SEA
-
BHD
21h 25m
1 stop
British Airways Logo
12:40 pm - 6:25 pm
BHD
-
SEA
13h 45m
1 stop
$900British Airways
Mon, Oct 19 - Wed, Oct 21
British Airways Logo
1:30 pm - 12:55 pm
SEA
-
BHD
15h 25m
1 stop
British Airways Logo
4:05 pm - 6:25 pm
BHD
-
SEA
34h 20m
1 stop
$909British Airways
Mon, Oct 19 - Wed, Oct 21
British Airways Logo
8:20 pm - 6:45 pm
SEA
-
BHD
14h 25m
1 stop
British Airways Logo
8:35 pm - 11:35 am
BHD
-
SEA
23h 00m
1 stop
$910British Airways
Mon, Oct 5 - Thu, Oct 22
British Airways Logo
11:34 am - 12:55 pm
SEA
-
BHD
17h 21m
2 stops
British Airways Logo
12:45 pm - 6:25 pm
BHD
-
SEA
13h 40m
1 stop
$913British Airways
Mon, Oct 5 - Thu, Oct 22
British Airways Logo
11:34 am - 12:55 pm
SEA
-
BHD
17h 21m
2 stops
British Airways Logo
9:35 am - 6:25 pm
BHD
-
SEA
16h 50m
1 stop
$914British Airways
Mon, Oct 5 - Thu, Oct 22
British Airways Logo
11:34 am - 12:55 pm
SEA
-
BHD
17h 21m
2 stops
British Airways Logo
6:30 am - 6:25 pm
BHD
-
SEA
19h 55m
1 stop
$915British Airways
Mon, Aug 17 - Tue, Aug 25
Multiple Airlines Logo
3:40 pm - 10:25 pm
SEA
-
BFS
22h 45m
3 stops
Multiple Airlines Logo
11:30 pm - 9:40 am
BFS
-
SEA
42h 10m
3 stops
$971Multiple Airlines
Mon, Aug 17 - Tue, Aug 25
Multiple Airlines Logo
6:10 pm - 10:25 pm
SEA
-
BFS
20h 15m
2 stops
Multiple Airlines Logo
6:15 am - 3:40 pm
BFS
-
SEA
17h 25m
2 stops
$975Multiple Airlines
Booking Insights

KAYAK's insights & trends for Seattle to Belfast flights

Get data-powered insights and trends into flights from Seattle to Belfast to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest month to fly from Seattle to Belfast?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Seattle to Belfast, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Seattle to Belfast is January, where tickets cost $0 (return) on average. On the other hand, the most expensive months are December and June, where the average cost of round-trip tickets is $1,583 and $1,327 respectively.

Good to know

Cheapest flight$310
Flight from Seattle to Belfast Intl Airport

When to book flights from Seattle to Belfast

Are your dates flexible? Find out the best times to travel from Seattle to Belfast based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Seattle to Belfast

  • What is the cheapest flight from Seattle to Belfast?

    In the last 3 days, the lowest price for a flight from Seattle to Belfast was $310 for a one-way ticket and $890 for a round-trip.

  • Do I need a passport to fly between Seattle and Belfast?

    Yes, you’ll need a passport to travel to Belfast from Seattle.

  • Which airports will I be using when flying from Seattle to Belfast?

    Seattle is served by only 1 airport and there are 2 airports in Belfast. You will leave Seattle from Seattle/Tacoma Intl and you will be arriving in Belfast at one of these airports: Belfast Intl or Belfast City.

  • Which aircraft models fly most regularly from Seattle to Belfast?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Seattle to Belfast?

    oneworld is the only airline alliance operating flights between Seattle and Belfast.

  • How does KAYAK find such low prices on flights from Seattle to Belfast?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Seattle to Belfast.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Seattle to Belfast?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Belfast from Seattle is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Seattle to Belfast?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Belfast with an airline and back to Seattle with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Seattle to Belfast?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Belfast from Seattle up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airline flying from Seattle to Belfast

 
See real verified KAYAK customer reviews for airlines flying from Seattle to Belfast. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Seattle to Belfast? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
6.7
British AirwaysOverall score based on 7944 reviews
6.9Boarding
6.4Food
6.8Comfort
6.4Entertainment
7.7Crew
Airline reviews

Cancelled flight and re booked seats were a downgrade. British Airways said the upgrade was t available but when I checked it was but then they wouldn’t make it right

2.0 MediocreAnonymous, May 2026
ORD - LHR
Read more British Airways reviews

Cancelled flight and re booked seats were a downgrade. British Airways said the upgrade was t available but when I checked it was but then they wouldn’t make it right

Boarding was orderly, pilot and flight attendants were nice, entertainment options were good, and low sodium meals were quite tasty.

The whole experience was excellent, O can say out from Miami the best airline to travel with for any European destination. Since the ground staff to the inflight crew attention was great, service on board 10 of 10. Finally the 380 is very confortable and nice to travel.

All crew except 1 were excellent. When I asked assistance with business class seat conversion to a bed (not being familiar as never used before but have numerous times with other airlines) crew member helped very reluctantly. I should have told her that business class seat conversion is totally different in each airline such as Delta, New Zealand Air and United. Sorry it was my 1st time with America Airlines. Now I know, I won't bother asking assistance in future.

The seats in Premier Economy were very comfortable. The food was better than average. The way British Airways handled our seating was atrocious.

Flight delayed, connection was not at gate listed and so missed, staff were rude at Heathrow, phone tree stupid and difficult, took me 21 actual hours to reach my destination. Almost lost my hotel reservation after walking in a strange city alone after midnight because they would not put me up in a hotel at sfo or heathrow. I will never fly BA again and will tell all people and Instagram followers never to fly BA.

Overall ok. Best part has always been the sundae dessert.

I’ve never been on a trans-Atlantic (or Pacific) flight where the seats don’t recline—not even a little. I asked my seat mate when BA starting doing this and he said “Oh, a few years ago.” I couldn’t sleep, with my head falling forward waking me continuously, and came off the plane incredibly stiff. I booked a Premium Economy seat to get a more comfortable seat, which was worse than most basic Economy seats I’ve ever booked.

Nice aircraft. Good crew. Delayed departure from Houston, but arrived on time in London. Main thing I don’t like about flying BA is having to transit through security in London Heathrow. A major pain!

The gate agent made me check my carry-on in Denver, even though I've traveled all over taking this case on the plane. Beware folks. Food in Premium Economy was quite good - excellent blanket! Flight attendants on the Heathrow-to-Budapest flight on 3-27-2026 were quite snappy. I got a frown when asked to unscrew the water bottle cap for me (I had a cast on my right arm). Also woke up right when they were handing out biscuits. She had given my rowmates one and was in the process of giving water when I asked for a biscuit. She scolded me and said, "You snooze, you lose". She did give me one, but I thought that comment was uncalled for.

Everything you need to know for your flight from Seattle to Belfast

Information on your arrival and departure airports