$383 Find Cheap Flights from Seattle to Belfast - Compare and Save

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 8/23. 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

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Everything you should know

Cheapest round-trip
$907
British Airways
Sun 11/15Wed 11/18
SEA - BHD • 1 stop
Cheapest one-way
$294
Multiple Airlines
Sun 8/23
SEA - BHD • 3 stops
Top airlines
Cheapest • from $907 (round-trip)
Best reviews • 6.7 score
Airline reviews
Airline reviews
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Airline reviews
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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

Sun, Nov 15 - Wed, Nov 18
British Airways Logo
6:45 pm - 4:50 pmSEA  Seattle/Tacoma Intl-BHD Belfast City
14h 05m1 stop London Heathrow
British Airways Logo
9:15 am - 4:50 pmBHD  Belfast City-SEA Seattle/Tacoma Intl
15h 35m1 stop London Heathrow
$907British Airways
Sun, Nov 15 - Wed, Nov 18
British Airways Logo
6:45 pm - 4:50 pmSEA  Seattle/Tacoma Intl-BHD Belfast City
14h 05m1 stop London Heathrow
British Airways Logo
9:15 am - 4:50 pmBHD  Belfast City-SEA Seattle/Tacoma Intl
15h 35m1 stop London Heathrow
$908British Airways
Sun, Nov 15 - Wed, Nov 18
British Airways Logo
6:45 pm - 4:50 pmSEA  Seattle/Tacoma Intl-BHD Belfast City
14h 05m1 stop London Heathrow
British Airways Logo
9:15 am - 4:50 pmBHD  Belfast City-SEA Seattle/Tacoma Intl
15h 35m1 stop London Heathrow
$909British Airways
Sun, Jan 24 - Thu, Jan 28
British Airways Logo
6:45 pm - 6:40 pmSEA  Seattle/Tacoma Intl-BHD Belfast City
15h 55m1 stop London Heathrow
British Airways Logo
3:25 pm - 4:50 pmBHD  Belfast City-SEA Seattle/Tacoma Intl
33h 25m1 stop London Heathrow
$916British Airways
Mon, Oct 5 - Thu, Oct 22
British Airways Logo
8:20 pm - 7:25 pmSEA  Seattle/Tacoma Intl-BHD Belfast City
15h 05m1 stop London Heathrow
British Airways Logo
12:45 pm - 6:25 pmBHD  Belfast City-SEA Seattle/Tacoma Intl
13h 40m1 stop London Heathrow
$945British Airways
Mon, Oct 5 - Thu, Oct 22
American Airlines Logo
3:14 pm - 3:30 pmSEA  Seattle/Tacoma Intl-BHD Belfast City
16h 16m2 stops Chicago O'Hare Intl London Heathrow
American Airlines Logo
2:20 pm - 11:35 amBHD  Belfast City-SEA Seattle/Tacoma Intl
29h 15m1 stop London Heathrow
$970American Airlines
Mon, Aug 24 - Sat, Aug 29
Multiple Airlines Logo
7:00 pm - 9:35 pmSEA  Seattle/Tacoma Intl-BFS Belfast Intl
18h 35m3 stops Reykjavik Keflavik Intl Kastrup Copenhagen Edinburgh Turnhouse
Multiple Airlines Logo
10:25 pm - 9:40 amBFS  Belfast Intl-SEA Seattle/Tacoma Intl
43h 15m3 stops Glasgow Intl Dublin Calgary
$1,063Multiple Airlines
Tue, Sep 1 - Mon, Sep 7
Multiple Airlines Logo
8:00 am - 4:25 pmSEA  Seattle/Tacoma Intl-BFS Belfast Intl
24h 25m2 stops Toronto Pearson Intl Manchester
Multiple Airlines Logo
8:40 am - 11:55 amBFS  Belfast Intl-SEA Seattle/Tacoma Intl
35h 15m2 stops Manchester Frankfurt am Main
$1,068Multiple Airlines
Tue, Sep 1 - Mon, Sep 7
Multiple Airlines Logo
7:00 pm - 7:40 pmSEA  Seattle/Tacoma Intl-BFS Belfast Intl
16h 40m2 stops Reykjavik Keflavik Intl Glasgow Intl
Multiple Airlines Logo
8:15 am - 11:45 amBFS  Belfast Intl-SEA Seattle/Tacoma Intl
35h 30m2 stops London Gatwick Reykjavik Keflavik Intl
$1,072Multiple Airlines
Wed, Dec 9 - Wed, Dec 30
American Airlines Logo
10:31 am - 2:15 pmSEA  Seattle/Tacoma Intl-BHD Belfast City
19h 44m2 stops Chicago O'Hare Intl London Heathrow
American Airlines Logo
6:35 am - 6:43 pmBHD  Belfast City-SEA Seattle/Tacoma Intl
20h 08m2 stops London Heathrow Los Angeles
$1,087American 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.

Which airlines provide the cheapest flights from Seattle to Belfast?

The cheapest round-trip price for the route for each airline clicked by KAYAK users in the last 5 days.

In the past 5 days, the cheapest round-trip tickets from Seattle to Belfast were found on British Airways ($907) and American Airlines ($970).

Good to know

Cheapest flight

$383
Flight from Seattle to Belfast City 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 5 days, the lowest price for a flight from Seattle to Belfast was $383 for a one-way ticket and $907 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 8147 reviews
7.7Crew
6.8Comfort
6.5Entertainment
7.0Boarding
6.4Food
Airline reviews

Meh. Lived the seat. The entertainment unit did not work and had to be reset 3 times. Service was SLOW taking over 90 min to be served. Crew forgot about my meal. Chicken was dry and almost inedible.

6.0 GoodAnonymous, Jun 2026
Read more British Airways reviews

Meh. Lived the seat. The entertainment unit did not work and had to be reset 3 times. Service was SLOW taking over 90 min to be served. Crew forgot about my meal. Chicken was dry and almost inedible.

Flying on the Boeing 787 from Seattle to London was everything that I expected. Every thing was great.

Moved me away from my family and refused to fix it.

Connection at Hethrow was horrible..We couldn't get out of the plane for an hour as they were buying people to the airport and there were not enough busses. We had 2 and half hf between flights so it was very tight. After departing plane we had to go thru security again. People with less time in between connections missed their flights

Captain sick. Unable to get replacement so delayed me 30 hours, many others delayed 54 hours. TOTALLY DESTROYED ALL MY PLANS, including lost my rental car which would now cost over 5 times what I paid so stuck with buses n trains... lost hotel reservations.... HORRIBLE!!!

The BA business class cabin is excellent,very comfortable for sleeping but the service could be improved.

The flight from Seattle was delayed, which made me miss my connection to Florence. I was re-booked NINE HOURS LATER!!! That’s basically a vacation day lost. British Airways needs to partner with other airlines when possible to get a more realistic travel time, if delays occur. I realize there aren’t many flights to Florence from London, so I would book differently were I to return. The actual flight from Seattle was very comfortable and the crew was great, no faults there. I enjoy British Airways, this was an anomaly.

Could have done with a 2nd round of drinks even if it was only to distribute bottled water

The second leg of my flight unexpectedly got canceled. I was stuck at the airport for the whole day and instead of flying out that morning I flew out in the evening. For some of my fellow passengers it was the second cancellation and their original flight was supposed to go out the day before. There was no reason given though getting rebooked was quick even though I would have preferred if I would have been on one of the earlier flights that day. Compensation was a £10 voucher for some food at the airport. I eventually arrived without further incident but but due to the cancellation, it was one of my more frustrating travels of my life.

Due to a cyber attack at the SeaTac airport ALL of the airport computers at the airport were down. This seriously impacted every airline at the airport and the resulted in our flight leaving a hour later than scheduled. This delay caused us to miss our connecting flight from Heathrow to Edinburgh. I was amazed to have British Airways staff meet us at the gate as we left our flight. They quickly provided us with new boarding passes for a flight going to Edinburgh later the same day. Problems sometimes happen but they handled the situation in first class style.

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

Information on your arrival and departure airports