| Castelnuovo di Val di Cecina | |
| Coordinates: | 43.2167°N 64°W |
| Region: | Tuscany |
| Province: | Pisa (PI) |
| Frazioni: | Montecastelli Pisano, Sasso Pisano |
| Mayor: | Alberto Ferrini |
| Area Total Km2: | 89.02 |
| Population Total: | 2198 |
| Population As Of: | 30 June 2017[1] |
| Population Demonym: | Castelnuovini |
| Elevation M: | 576 |
| Saint: | St. Salvatore |
| Day: | 9 November |
| Postal Code: | 56041 |
| Area Code: | 0588 |
Castelnuovo di Val di Cecina is a comune (municipality) in the Province of Pisa in the Italian region Tuscany, located about 70km (40miles) southwest of Florence and about 70 km southeast of Pisa.
Castelnuovo di Val di Cecina borders the following municipalities: Casole d'Elsa, Monterotondo Marittimo, Montieri, Pomarance, Radicondoli, Volterra.