Carbonia-Iglesias (Italian: Provincia diCarbonia-Iglesias, Sardinian: Provìntzia de Carbònia-Igrèsias is a province in the autonomous region of Sardinia, Italy which includes the historical region of Sulcis-Iglesiente, the southwestern part of Sardinia. The largest municipalities of the province are the two co-capitals, Carbonia (population 30,447 in 2001 census), and Iglesias (28,170). Another important comune is Sant'Antioco (11,730), located on the small island of the same name.

These are all the comuni in this province:

Buggerru, Calasetta, Carbonia, Carloforte, Domusnovas, Fluminimaggiore, Giba, Gonnesa, Iglesias, Masainas, Musei, Narcao, Nuxis, Perdaxius, Piscinas, Portoscuso, San Giovanni Suergiu, Santadi, Sant`Anna Arresi.