Nigrospora sphaerica is an airborne filamentous fungus in the phylum Ascomycota. It is found in soil, air, and plants as a leaf pathogen. It can occur as an endophyte where it produces antiviral and antifungal secondary metabolites. Sporulation of N. sphaerica causes its initial white coloured colonies to rapidly turn black. N. sphaerica is often confused with the closely related species N. oryzae due to their morphological similarities.