Susiana (Persian: سوزیانا; [ʔæhˈvɒːz]) was an ancient cultural and geographical region located in southwestern Iran. It broadly corresponds to the alluvial lowlands surrounding the city of Susa, forming the core area of the early Elamite civilization, which today make up most of modern Khuzestan Province.
Susiana is best understood as the Susa plain, an ecological and cultural zone influenced both by the Iranian plateau and by Mesopotamia. Archaeological surveys show continuous settlement in the region from the Neolithic period onward, especially at sites such as Chogha Bonut and Chogha Mish. Recent excavations at Tappeh Senjar have added substantial data on the development of Susiana from the Proto-Elamite to the Shimashki periods.