G. giganteus

G. giganteus may refer to:
 * Geosaurus giganteus, an extinct marine crocodyliform reptile species from Western Europe of the Late Jurassic
 * Gigantopithecus giganteus, an extinct large ape species that lived in what is now India
 * Gymnopilus giganteus, a mushroom species

Synonyms

 * Gastrochilus giganteus, a synonym for Rhynchostylis gigantea, an orchid species