Aleptina arenaria is a moth of the family Noctuidae.

It is only known from the White Sands National Park, Otero County, New Mexico.

The length of the forewings is 10 mm for males and females.

Adults are grey with normal noctuid transverse markings and spots.

The specific epithet of this species, arenaria calls attention to the specialized sandy habitat where Aleptina arenaria was discovered.