This is a list of the Areas of Special Scientific Interest (ASSIs) in County Down in Northern Ireland, United Kingdom.
As with SSSIs, these sites are designated if they have criteria based on fauna, flora, geological or physiographical features.
On top of this, structures are also covered, such as the Whitespots mines in Conlig, according to several criterion including rarity, recorded history and intrinsic appeal.
[1] For other sites in the rest of the United Kingdom, see List of SSSIs by Area of Search.
Data is available from the Northern Ireland Environment Agency's website in the form of citation sheets for each ASSI.