| Castelletto Monferrato | |
| Official Name: | Comune di Castelletto Monferrato |
| Coordinates: | 44.9833°N 42°W |
| Region: | Piedmont |
| Province: | Alessandria (AL) |
| Frazioni: | Giardinetto, Gerlotti |
| Mayor: | Gianluca Colletti |
| Area Total Km2: | 9.58 |
| Population Total: | 1473 |
| Population As Of: | 31 December 2019 |
| Population Demonym: | Castellettesi |
| Elevation M: | 197 |
| Postal Code: | 15040 |
| Area Code: | 0131 |
Castelletto Monferrato (pms|Castlèt Monfrà) is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about 70km (40miles) east of Turin and about 8km (05miles) northwest of Alessandria. As of 31 December 2004, it had a population of 1,511 and an area of 9.4km2.[1]
The municipality of Castelletto Monferrato contains the frazioni (subdivisions, mainly villages and hamlets) Giardinetto and Gerlotti.
Castelletto Monferrato borders the following municipalities: Alessandria, Quargnento, and San Salvatore Monferrato.