Sclerococcum aptrootii is a species of lichenicolous fungus in the family Dactylosporaceae.

Found in Puerto Rico, it was formally described as a new species in 2015 by Belgian mycologist Paul Diederich.

The type specimen was collected in Maricao State Forest north of Sabana Grande (Mayagüez), at an altitude of 800 m (2,600 ft); here, in a low mountain forest, it was found growing on the lichen Fissurina dumastii.

The fungus forms black, rounded sporodochia that measure 50–100 μm in diameter; it does not otherwise damage the host.

The species epithet honours Dutch lichenologist André Aptroot, who collected the type in 1989.