Gastornis is a species of large flightless bird in the family Gastornithidae, somewhat related to modern waterfowl and game birds. Fossils are found in Eurasia and North America. Originally, it lived from about 60 to 47 million years ago, from the Selandian to Lutetian ages of the Paleogene period. Several species are known:
- G. parisiensis
- G. gigantea
- G. sarasini
- G. geiselensis
- G. russeli
- G. xichuanensis
- G. laurenti
