Cheap Flights from Seattle to Belfast

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Find the cheapest month or even day of the year to fly to Belfast

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Find the cheapest month to fly from Seattle to Belfast

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Seattle to Belfast flights are currently cheapest in March.

Alternative Seattle to Belfast routes

Looking for the cheapest, fastest or easiest route from Seattle to Belfast? You could fly into the following airports instead.

Seattle to Belfast: Flight information

The things to know before you go.
Cheapest flight found$1,576
Cheapest month to flyApril

Finding cheap flights from Seattle to Belfast: Frequently asked questions

There are 2 airports in Belfast: Belfast City and Belfast International.
The best price we found for a return flight from Seattle to Belfast is $1,576. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
Currently, there are no airlines that fly direct from Seattle to Belfast. But we found flights with one or more stops from $1,576.
As of March 2026, there are no flights flying from Seattle to Belfast.
The cheapest month to fly from Seattle to Belfast is usually April.
If you're flying from Seattle, the cheapest airport near Belfast is Belfast City – which is 3.7 km away from the centre of Belfast. We've found flights into this airport from $1,576.
After crunching the numbers on our flight calendar, we found that it is currently cheapest to fly from Seattle to Belfast on Sunday, 26 April 2026.
No airlines currently offer direct flights between Seattle and Belfast. Most routes have one or more stops.
We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to Belfast but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.
We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to Belfast is around 40 days in advance, so don’t leave your flight to the last minute.
In March, the average temperature is usually around 6°C. August is typically the warmest month in Belfast, when it usually averages around 17°C. You can expect the least rain in May. The coldest month is January, with temperatures averaging 4°C. The rainiest month is October.
The cheapest airline that flies to Belfast is British Airways .

Travelling from Seattle to Belfast: what you need to know

  • There are two main airports you can fly out of in Seattle. Check out your options leaving from Seattle-Tacoma International Airport (SEA) or Lake Union Sea Plane Base Airport (LKE) when booking your flight from Seattle to Belfast.

  • Arrive in Belfast at Belfast International Airport (BFS) or George Best Belfast City Airport (BHD).

  • Belfast's timezone is UTC+0, making Belfast seven hours ahead of Seattle.

  • For a smooth journey, arrive at the airport two hours ahead of international flights and one hour before domestic departures. This will give you enough time to catch your Seattle to Belfast flight.

  • During popular months such as July, you'll want to get to the airport well in advance. Plan to arrive two hours before domestic departures and four hours ahead of an international flight when you travel during high season in general.

How to find the cheapest flights from Seattle to Belfast

  • Don't leave everything to the last minute. You're more likely to get cheap Seattle to Belfast flights if you book ahead. Airlines often have some amazing early bird rates.

  • If you're flexible with your trip dates, try using the 'Whole month' tool. It'll give you the lowest price in each month when searching for your plane ticket from Seattle to Belfast.

  • You don't need to check every day to see if fares have dropped when you set up a Price Alert. We'll notify you the moment a better deal comes up on cheap flights from Seattle to Belfast.

  • Tailor your trip using filters. Choose your preferred departure and arrival times, total journey duration and airlines. You can also sort your results by 'Best,' 'Fastest' or 'Cheapest' Seattle to Belfast flights.

Flying from Seattle

Seattle-Tacoma International Airport (SEA)

  • Consider adding a stopover to possibly find a cheaper Seattle to Belfast flight. Simply deselect 'Direct flights only' when searching for departures from Seattle-Tacoma International Airport. Break up your trip (and maybe save some cash) by stopping at one of these airports:

    • London Heathrow Airport (LHR)

    • Amsterdam Airport Schiphol (AMS)

    • Frankfurt Airport (FRA)

  • Located around 18 kilometres from the centre of Seattle, SEA can be reached in about 20 minutes by car, depending on traffic. The journey on public transport takes roughly 55 minutes.

  • Want an easy start to your trip? Stay near Seattle-Tacoma International Airport. Whether you're taking an early flight from Seattle to Belfast or want to avoid feeling rushed, these hotels are just the thing:

  • 81.27% of flights leaving Seattle-Tacoma International Airport arrive at their destination as planned. Given its strong on-time stats, disruptions are unlikely when setting off from SEA.

Arriving in Belfast

Belfast International Airport (BFS)

  • Belfast International Airport (BFS) is approximately 19 kilometres from the centre of Belfast. If you're catching a cab or a ride-share, the drive will take around 30 minutes.

  • It typically takes 2 hours to get there on public transport.

  • If you're coming in on a late flight from Seattle to Belfast, few things beat the convenience of staying near the terminal. Grab your suitcases from the carousel and then be showered and relaxing not long after at one of these accommodation options near BFS:

  • Follow your own route with a Belfast International Airport rental car. Book your wheels from Budget, Drivalia or Dollar and see more of Belfast and beyond.

  • To secure the lowest price, reserve your vehicle from Belfast International Airport about three weeks ahead of your Seattle to Belfast flight.

George Best Belfast City Airport (BHD)

  • Central Belfast is around 5 kilometres from George Best Belfast City Airport (BHD). After your flight from Seattle to Belfast has touched down and you've navigated your way to arrivals, the drive should take about 10 minutes.

  • The trip will take approximately 20 minutes on public transport.

  • There are some comfortable places to call home for the night near BHD. Settle in and get cosy after your Seattle to Belfast flight at one of these perfectly located options:

  • Forget about inconvenient public transport schedules or waiting in a long cab line. Pick up a George Best Belfast City Airport rental car and let your trip unfold on your terms. Compare rates and availability from Budget, Sixt and Alamo.

  • Get what you want, not just what's left over. Securing your ride from BHD two weeks in advance often means more savings and a wider selection of vehicles.

Best time to go to Belfast

  • It's time to work out your travel dates for your flight from Seattle to Belfast. August is the busiest month to travel to Belfast. If you prefer a more relaxed atmosphere, go in January.

  • The warmest month in Belfast is July, with temperatures ranging between 10ºC and 19ºC. Lock in your Seattle to Belfast ticket then if you enjoy this type of weather.

  • January sees average temperatures of between 1ºC and 8ºC. Look for cheap flights from Seattle to Belfast around that time if you like travelling in cooler conditions.

More about Belfast

  • When it comes to searching for somewhere to rest your head, you'll find the most popular stays in Belfast right here. Browse these hotels after locking in your flight from Seattle to Belfast:

  • Every great holiday has to include a little sightseeing. Titanic Belfast, Crumlin Road Gaol Visitor Attraction and Conference Centre and Botanic Gardens are must-do's during your Belfast adventure.

Explore more of United Kingdom

  • Belfast has plenty going for it, but there are so many other parts of United Kingdom just waiting to be explored. Around 354 kilometres south-east of Belfast, a trip to Birmingham will keep you on the move. Start with attractions like Cadbury World, The Library of Birmingham and National Sea Life Centre.

  • Around 418 kilometres south-east of Belfast, Bristol is another favourite stop in United Kingdom. No visit is complete without checking out Clifton Suspension Bridge, Cabot Tower and Brandon Hill Nature Park.

Prices shown on this page are estimated lowest prices only. Found in the last 45 days.