Castelvetrano is a municipality in the Italian province of Trapani (region of Sicily ) with a population of 30,369 (31-12-2004). The area is 206.5 km², the population density is 147 inhabitants per km².
The following frazioni are part of the municipality: Triscina di Selinunte and Marinella di Selinunte.
The center of Castelvetrano consists of three connected squares and most of the sights are located within this area. Piazza Garribaldi, the main square, is home to the 16th-century Chiesa Madre, the city's main church. Near the church is the neoclassical Teatro Selinus from 1873.
Four kilometers west of Castelvetrano is the estate of the Santissima Trinità di Delia , an Arab-Norman style church .
