| Castel Frentano | |
| Official Name: | Comune di Castel Frentano |
| Coordinates: | 42.2°N 35°W |
| Region: | Abruzzo |
| Province: | Chieti CH) |
| Frazioni: | Ciommi, Colle Ceraso, Crocetta, Feltrino, Lentesco, Pera, Pietragrossa, Porrechi, San Rocco, San Vincenzo, Trastulli |
| Mayor: | Patrizia De Santis Ciarrapico |
| Area Total Km2: | 21.89 |
| Population Total: | 4264 |
| Population As Of: | 1 January 2023 |
| Population Demonym: | Castellini |
| Elevation M: | 400 |
| Saint: | St. Stephen |
| Day: | 3 August |
| Postal Code: | 66032 |
| Area Code: | 0872 |
Castel Frentano is a comune (municipality) in the province of Chieti, in the Italian region of Abruzzo.
During World War II, the town was liberated by the New Zealand Army (2nd New Zealand Division) on 2 December 1943.
It is known for bocconotto, a typical dessert.