Casteltermini is a comune in the Province of Agrigento in the Italian region Sicily, located about 70 kilometres southeast of Palermo and about 25 kilometres north of Agrigento. Casteltermini borders the following municipalities: Acquaviva Platani, Aragona, Cammarata, Campofranco, San Biagio Platani, Sant'Angelo Muxaro, Santo Stefano Quisquina, Sutera.