San Ponziano church, Religious building in Carbonia, Italy.

San Ponziano church is a neo-Romanesque church on Piazza Roma in Carbonia, designed by Cesare Valle and Ignazio Guidi. Its rectangular plan has a central nave and two side aisles. The exterior is clad in granite and trachyte, and the square trachyte bell tower, 44.7 metres high, reproduces in scale the campanile of the Basilica of Santa Maria Assunta in Aquileia.

The foundation stone was laid on 29 January 1938 by Bishop Giovanni Pirastru of Iglesias, who dedicated the church to Saint Pontian because the saint had been exiled to the Sardinian mines. The church was designed by Cesare Valle and Ignazio Guidi and inaugurated on 18 December 1938, the same day as the city of Carbonia, founded for the exploitation of the Sulcis coal basin. Bombings in 1943 destroyed the original rose window.

The church is dedicated to Saint Pontian, chosen because he was exiled to the Sardinian mines by Emperor Maximinus Thrax; Saint Barbara was also named patron of the new town. Inside, a wooden Via Crucis designed by Eugenio Tavolara and carved by Pasquale Tilocca was placed at the 1938 inauguration.

The building is typically open during prayer times and can be visited by guests. It is helpful to check opening hours in advance, as these may change during religious festivities and important Catholic celebrations.

The 44.7-metre trachyte bell tower beside the church is a scaled-down copy of the campanile of the Basilica of Santa Maria Assunta in Aquileia. Inside, a wooden Via Crucis designed by Eugenio Tavolara and carved by Pasquale Tilocca was placed in 1938, the year the city was inaugurated.