The medieval village of Castelnuovo was part of the fief of the Agnello family from Senerchia. The current toponym, adding Cilento, was adopted in 1861, after the Italian unification.[3]
The territory of Castelnuovo is served by a pair of railway stations, Vallo della Lucania-Castelnuovo and Casal Velino, both on the Naples-Reggio Calabria line. The first one is located in Vallo Scalo and is also served by long-distance trains, the second is located in Velina, and is out of service. It is also served by the highway SP 430 Battipaglia-Agropoli-Vallo-Sapri, at the exit "Vallo Scalo-Salento".
