The Ubaid period is a prehistoric period of Mesopotamia. The name derives from Tell al-'Ubaid where the earliest large excavation of Ubaid period material was conducted initially in 1919 by Henry Hall and later by Leonard Woolley.

Tell al-'Ubaid is a low, relatively small tell west of nearby Ur in southern Iraq's Dhi Qar Governorate. Most of the remains are from the Chalcolithic Ubaid period, for which Tell al-'Ubaid is the type site, with an Early Dynastic temple and cemetery at the highest point. It was a cult center for the goddess Ninhursag.