Crassostrea ingens is a species of fossil oyster, a marine bivalve mollusk in the family Ostreidae, the oyster. This species lived during the Pliocene. Fossils have been found in New Zealand shallow-water limestone and shellbeds. Locations include the Wairarapa, Whanganui basin, Gisborne district, North Canterbury, and Hawke's Bay (especially in the Te Aute limestone).