Ninḫursaĝ sometimes transcribed Ninursag, Ninḫarsag, or Ninḫursaĝa, also known as Damgalnuna or Ninmah, was the ancient Sumerian mother goddess of the mountains, and one of the seven great deities of Sumer. She is known earliest as a nurturing or fertility goddess. Temple hymn sources identify her as the "true and great lady of heaven" and kings of Lagash were "nourished by Ninhursag's milk". She is the tutelary deity to several Sumerian leaders.

Sumer is the earliest known civilization, located in the historical region of southern Mesopotamia, emerging during the Chalcolithic and early Bronze Ages between the sixth and fifth millennium BC. Like nearby Elam, it is one of the cradles of civilization, along with Egypt, the Indus Valley, the Erligang culture of the Yellow River valley, Caral-Supe, and Mesoamerica. Living along the valleys of the Tigris and Euphrates rivers, Sumerian farmers grew an abundance of grain and other crops, a surplus which enabled them to form urban settlements. The world's earliest known texts come from the Sumerian cities of Uruk and Jemdet Nasr, and date to between c. 3350 – c. 2500 BC, following a period of proto-writing c. 4000 – c. 2500 BC.