E. De Felice notes that the surname derives from the place name Càpua and from the forms with the preposition Di or De Capua, as well as from the gentilic Capuano, meaning "inhabitant or native of Capua". He indicates that its diffusion extends from the Naples area towards the whole of southern Italy.

E. Rossoni provides a more detailed distribution: the surname is documented in Lazio —particularly in Amaseno, in the Frosinone area, and in Rome—, in Campania and in Calabria, with special presence in the Cosenza area. Rossoni also adds an etymological hypothesis: the name of the city of Capua, situated in the Caserta area, could go back to the name of a Samnite chieftain called Capye, to whom its conquest is attributed.