The authors agree that this surname derives from the medieval name Rodolfus, in turn coming from the Germanic name Hrodulf, composed of hroth ("glory" or "fame") and wulfa ("wolf"), with the meaning of "glorious wolf." It is, therefore, a surname of patronymic origin, arisen from the name of the first bearer.

F. Miranda notes that surnames of Lombard and Germanic root come mostly from personal names formed of two elements that exalted the virtues of strong and valiant individuals. He observes that the surname has its main nucleus in Sicily, with a presence in the provinces of Messina, Catania, Enna, Caltanissetta, Palermo, Ragusa and Syracuse, and ramifications in Friuli-Venezia Giulia, Lombardy, Piedmont, Veneto, Tuscany and Lazio.

V. Blunda, on the other hand, highlights that the surname is preserved especially in the centre of Italy, particularly in Tuscany. As a fact of cultural interest, he mentions Ridolfo del Ghirlandaio (1483–1561), a painter of Florence who maintained his father Domenico's workshop and contributed to sustaining the pictorial tradition of the Quattrocento in the transition towards Mannerism.