| Casalduni | |
| Official Name: | Comune di Casalduni |
| Province: | Benevento (BN) |
| Frazioni: | Acquaro, Brendice, Capitorto, Casale, Cerconi, Collemarino, Collemastarzo, Crocella, Cuolli, Ferrarisi, Gentile, Lanzate, Macella, Pescomandarino, Pezzalonga, Piana, Prato, San Fortunato, Santa Maria, Tacceto, Vado della Lota, Vaglie, Zingolella |
| Area Total Km2: | 23.2 |
| Elevation M: | 300 |
| Population Total: | 1293 |
| Population As Of: | 1 January 2020 |
| Population Footnotes: | [1] |
| Population Demonym: | Casaldunesi |
| Postal Code: | 82030 |
| Area Code: | 0824 |
| Istat: | 062015 |
| Saint: | Our Lady of Mount Carmel[2] |
| Day: | 16 July |
Casalduni is a comune (municipality) in the Province of Benevento in the Italian region Campania, located about 60 km northeast of Naples and about 15 km northwest of Benevento, on the slopes of Monte Cicco on the right of the Tammaro river.
Casalduni is mostly remembered as the location, along with Pontelandolfo, of a massacre of largely civilian population by the Piedmontese occupation troops in 1861.