The Greuthungs, Greuthungi, or Greutungi were a Gothic people of the Ukrainian steppes in the 3rd and the 4th centuries. They had close contacts with the Thervingi, another Gothic people, from west of the Dniester River. They may be the same people as the later Ostrogoths.
"Greuthungi" may mean "steppe dwellers" or "people of the pebbly coasts". The root greut- is probably related to the Old English greot, meaning "gravel, grit, earth" Polish grunt land, earth, ground This is supported by evidence that geographic descriptors were commonly used to distinguish people living north of the Black Sea both before and after Gothic settlement there and by the lack of evidence for an earlier date for the name pair Tervingi-Greuthungi than the late third century. It is also possible that the name "Greuthungi" has pre-Pontic Scandinavian origins. It may mean "rock people", to distinguish the Ostrogoths from the Gauts (in what is today Sweden).Jordanes does refer to an Evagreotingi (Greuthung island) in Scandza, but this may be legend. It has also been suggested that it may be related to certain place names in Poland, but this has met with little support.
Jordanes, a mid 6th-century historian identifies the 4th-century Greuthungi with the 5th/6th-century Ostrogothi. Jordanes also describes a large Greuthung kingdom in the late 4th-century, but Ammianus Marcellinus, a late 4th-century historian, does not record this. Many modern historians, including Peter Heather and Michael Kulikowski, doubt that it was ever particularly extensive (and suggest one or more smaller kingdoms).
In time and geographical area, the Greutungi and their neighbours, the Thervingi, correspond to the archaeological Chernyakhov culture.