Gibberula modica is a species of small sea snail, a marine gastropod mollusk in the family Cystiscidae, (previously placed in the family Marginellidae).
The shell size is 3 millimeters long, decorated with sandy yellows, browns, and whites. The opening is white, and the sides of the opening are ridged.
The species is endemic to São Tomé and PrÃÂncipe.