SEA

£475 Find Cheap Flights from Belfast to Seattle

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Belfast to Seattle departing on 3/8. 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 Seattle

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Belfast to Seattle, 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 Belfast to Seattle, as well as popular online travel agencies
Travellers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest return fare
£612
Multiple Airlines
Mon 20/4Mon 4/5
BFS - SEA • 2 stops
Cheapest one-way flight
£475
Multiple Airlines
Mon 3/8
BFS - SEA • 2 stops
Top airlines
KLM
Cheapest • from £647 (return)
American Airlines
Best reviews • 7.2 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Start a new search
KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to Seattle!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Belfast to Seattle

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for return flights from Belfast to Seattle 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 return flight deals from Belfast to Seattle

Mon, 20 Apr - Mon, 4 May
Multiple Airlines Logo
06:40 - 20:40
BFS
-
SEA
22h 00m
2 stops
Multiple Airlines Logo
19:00 - 16:15
SEA
-
BFS
13h 15m
2 stops
£612Multiple Airlines
Mon, 20 Apr - Mon, 4 May
Multiple Airlines Logo
19:35 - 20:40
BFS
-
SEA
33h 05m
3 stops
Multiple Airlines Logo
15:40 - 16:15
SEA
-
BFS
16h 35m
2 stops
£620Multiple Airlines
Mon, 20 Apr - Mon, 4 May
KLM Logo
17:30 - 11:45
BHD
-
SEA
26h 15m
1 stop
KLM Logo
08:50 - 09:20
SEA
-
BHD
16h 30m
2 stops
£647KLM
Mon, 20 Apr - Mon, 4 May
Multiple Airlines Logo
19:35 - 17:55
BFS
-
SEA
30h 20m
3 stops
Multiple Airlines Logo
15:40 - 23:20
SEA
-
BFS
23h 40m
3 stops
£647Multiple Airlines
Mon, 20 Apr - Mon, 4 May
Multiple Airlines Logo
19:35 - 11:35
BHD
-
SEA
24h 00m
1 stop
Multiple Airlines Logo
13:35 - 19:25
SEA
-
BHD
21h 50m
1 stop
£650Multiple Airlines
Mon, 20 Apr - Mon, 4 May
British Airways Logo
11:35 - 00:30
BHD
-
SEA
20h 55m
2 stops
British Airways Logo
15:17 - 15:30
SEA
-
BHD
16h 13m
2 stops
£667British Airways
Sat, 7 Mar - Tue, 10 Mar
British Airways Logo
06:35 - 11:30
BHD
-
SEA
12h 55m
1 stop
British Airways Logo
19:50 - 18:40
SEA
-
BHD
15h 50m
1 stop
£679British Airways
Sat, 7 Mar - Tue, 10 Mar
British Airways Logo
06:35 - 11:30
BHD
-
SEA
12h 55m
1 stop
British Airways Logo
07:21 - 10:30
SEA
-
BHD
20h 09m
2 stops
£683British Airways
Sat, 7 Mar - Tue, 10 Mar
British Airways Logo
09:15 - 23:04
BHD
-
SEA
21h 49m
2 stops
British Airways Logo
07:21 - 10:30
SEA
-
BHD
20h 09m
2 stops
£684British Airways
Sat, 7 Mar - Tue, 10 Mar
British Airways Logo
06:35 - 23:04
BHD
-
SEA
24h 29m
2 stops
British Airways Logo
07:21 - 11:30
SEA
-
BHD
21h 09m
2 stops
£687British Airways
Booking Insights

KAYAK’s insights & trends for Belfast to Seattle flights

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

Which airlines provide the cheapest flights from Belfast to Seattle?

The cheapest round-trip price for the route for each airline clicked by KAYAK users in the last 72 hours.

In the past 3 days, the cheapest return tickets from Belfast to Seattle were found on KLM (£647) and British Airways (£667).

Good to know - Cheap tickets from Belfast to Seattle

Cheapest flight£475
Flight from Belfast Intl Airport to Seattle

When to book flights from Belfast to Seattle

Are your dates flexible? Find out the best times to travel from Belfast to Seattle based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated return price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or returns 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 Belfast to Seattle

  • What is the cheapest flight from Belfast to Seattle?

    In the last 3 days, the lowest price for a flight from Belfast to Seattle was £475 for a one-way ticket and £612 for a return.

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

    There are 2 airports in Belfast (Belfast Intl and Belfast City.) and only 1 airport in Seattle (Seattle/Tacoma Intl). The cheapest flights are generally found on the Belfast City Airport to Seattle/Tacoma Intl flight route.

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

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

  • Which airline alliances offer flights from Belfast to Seattle?

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

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

    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 Belfast to Seattle.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Seattle from Belfast 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 Belfast to Seattle?

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

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

    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 Seattle from Belfast 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 Belfast to Seattle

 
See real verified KAYAK customer reviews for airlines flying from Belfast to Seattle. 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 Belfast to Seattle? 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.
7.2
American AirlinesOverall score based on 11313 reviews
7.2Comfort
7.5Boarding
6.9Entertainment
6.4Food
8.0Crew
Airline reviews

We missed our flight and got stranded in Miami where we had to rent a hotel we could not afford. they would not work with us because they said it was weather related even though the gate attendant said it was not. I could go on but trying to get satisfaction has wore me down, which I believe is the intent. My only solution is to never fly AA again.

2.0 MediocreScott, Feb 2026
CLT - MIA
Read more American Airlines reviews

We missed our flight and got stranded in Miami where we had to rent a hotel we could not afford. they would not work with us because they said it was weather related even though the gate attendant said it was not. I could go on but trying to get satisfaction has wore me down, which I believe is the intent. My only solution is to never fly AA again.

No Snacks or Entertainment. The flight was short, snacks should still be given.

We lost a day of our vacation because AA did not get the plane to the gate on time. Even though the gate attendant was very clear that it was not weather related, AA would do nothing because there was some snow that day. They basically said the gate attendant was wrong even though she was on the front line of the situation and they were not.

See prior comment about how Kayak mishandled my reservation and delayed my arrival by 6 hours.

American Airlines was great and worked very hard to change my ticket so I could get an earlier, direct flight back to Dallas. However, I was informed that Kayak made mistakes with my itinerary and classified my ticket as desiring to be on the earlier flight instead of taking the necessary step of calling AA to get me on the standby list. This ended up keeping me from being added to the standby list and delayed me getting home by 6 hours. I am happy to discuss this further with Kayak so they can correct their procedures so this won't happen again.

The flight was fine. It's the satellite terminal that supports American eagle flights is what sucks. There is only one food option and everything there is way overpriced. I mean I know it's airport pricing, but it's even crazier than that. I bought a sandwich in a plastic container for $18.

Beverage service was not good. Also just one service in 5 hr 30 min flight. No ask fir water ir anything beside one time beverage service.

The flight attendant use 1.5 hours to answer my call. My dirty food tray was unattended.

The flight was completely full. Crew was not happy. Everyone was rude and brusque. Travelling with an arm in a cast and seating in the first row of economy cabin (in front of the separation) I needed help retrieving my tray for the meal. A staff member literally threw the tray on my lap, without helping to take out the tray. Boarding was messy, with 300 people waiting in an encloses space with low ceiling. I will try to avoid AA next time I have a long flight.

Flight was delayed because of a bird strike. They had another plane available within 45 minutes.

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

Information on your arrival and departure airports