San Giovanni Suergiu is a town and comune located in the Province of Sulcis Iglesiente within the autonomous island region of Sardinia, Italy. The municipality is situated approximately 50 kilometres (31 mi) west of Cagliari and about 4 kilometres (2 mi) south of Carbonia.
The town has a population of 5,523 inhabitants. It serves as a local administrative center within the Sulcis Iglesiente province.