The authors agree that this surname derives fundamentally from the trade of the blacksmith or from the activity related to iron. E. Rossoni notes that it may come from the homonymous place name or from the medieval term ferraria ("smithy"), in reference to the trade of the blacksmith or to the proximity to an installation of that type. The surname is very spread throughout Italy.

F. Miranda broadens this view and indicates that the surname, together with its variants (Ferrari, Ferrarini, Ferraio, Ferraris), derives from nicknames linked to the trade of the first bearer: blacksmith or worker in the extraction or fusion of iron, expressed in Latin as faber ferrarius. In dialectal language, the corresponding form is firraru, with the sense of "blacksmith" or "farrier". Miranda also notes the existence of the place name Ferrara, provincial capital in Emilia-Romagna, as a possible source of the surname. The geographical distribution is homogeneous throughout the country, with prominent presence in Campania, Sicily, Lombardy, Puglia, Lazio, Basilicata, Tuscany, Abruzzo and Veneto.