The authors differ on the origin of the surname. E. Rossoni proposes a toponymic derivation: the name would come from localities mentioned in the Codex Diplomaticus cavensis under the form capano. Rossoni notes signs of its transformation into a surname in the second half of the 16th century, when the Capano, as princes of Pollica, controlled a coastal watchtower in the Salerno area.

V. Blunda, on the other hand, proposes a Greek etymology: the surname would derive from the personal name Capànos, preserved in the Byzantine tradition of southern Italy. According to Blunda, the Italianised spelling with intervocalic p would have been fixed in the onomastics of Sicily from that original proper name.

As for its geographical distribution, Rossoni documents presence of the surname in Campania —in the Naples and Salerno areas (Vibonati)—, in Basilicata —Potenza area (Lauria)—, in Puglia —Foggia (Deliceto), Lecce (Racale) and Bari (Corato) areas— and in Calabria —Cosenza (Belvedere Marittimo, Cosenza, San Donato di Ninea) and Catanzaro areas—. Blunda records it in Sicily.