Charopinesta sema, also known as the Blackburn Island pinhead snail, is a species of land snail that is endemic to Australia's Lord Howe Island group in the Tasman Sea.

[2] The depressedly turbinate to discoidal shell of the mature snail is 1.1 mm in height, with a diameter of 1.8 mm, and a low, stepped spire.

The whorls are rounded, with deeply impressed sutures and moderately spaced radial ribs.

It has a roundedly lunate aperture and widely open umbilicus.

[2] This extremely rare snail is known from a single empty shell from Blackburn Island.