The authors differ on the origin of this surname. F. Miranda proposes two possible etymologies: on the one hand, it derives from the Lombard name Ragin, which means "divine, enlightened counsel," a root present in the name Ragimperto, a Lombard king and king of Italy in the year 701; on the other hand, it could come from the Latin regina, applied to people who bore some relation or resemblance —even of behaviour— to a queen. R. Brondolo, on the other hand, holds that the surname comes from Raineri.

According to Miranda, the surname is distributed in numerous regions of Italy, with main nuclei in the Milan-Varese area, in Sicily, in Piedmont, and a notable presence in Liguria, Lazio, Emilia-Romagna, Tuscany and Veneto. In Sicily it appears in all the provinces, with a special concentration in the Catania, Palermo, Agrigento and Trapani areas. Brondolo places the surname in northern Italy.