| Sonnino | |
| Official Name: | Comune di Sonnino |
| Coordinates: | 41.4167°N 27°W |
| Region: | Lazio |
| Province: | Latina (LT) |
| Frazioni: | Capocroce, Cerreto, Frasso, La Sassa, Sonnino Scalo |
| Mayor: | Luciano De Angelis |
| Area Total Km2: | 63 |
| Population Total: | 7363 |
| Population As Of: | 31 May 2022 |
| Population Demonym: | Sonninesi |
| Elevation M: | 430 |
| Saint: | St. Gaspar del Bufalo and St. Mark |
| Day: | October 21 and April 25 |
| Postal Code: | 04010 |
| Area Code: | 0773 |
Sonnino is a town and comune in the province of Latina, in the Lazio region of central Italy.
It is the birthplace of Italian national team footballer Alessandro Altobelli, and Roman Catholic archbishop Velasio de Paolis.
Originating in the Early Middle Ages (the name deriving perhaps from the Latin sommum, meaning "top"), Sonnino is mentioned for the first time in a Papal bull from 999. It was held first by the De Sompnino, and was acquired by Onorato I Caetani in 1369. The castle was inhabited by the Caetani d'Aragona until they sold it in 1469 to the Colonna, who were later followed by the Antonelli and the Talani families.
In July 1819 Cardinal Ercole Consalvi, Secretary of State at the Vatican, ordered Sonnino to be razed to the ground as it had become a notorious haunt of the banditi in the Campagna di Roma.
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