The authors agree that Badino is a surname derived from a personal name of Germanic root.

Surnames in Italy considers that Badino, together with a group of related surnames, derives from more or less dialectal variants of the Germanic personal name Baldovino or Balduino (Balduinus in Medieval Latin), documented as early as the year 720 in a Lombard text of Lucca as Paldoín, with the later phonetic evolution p → b. The name spread in Italy through the Franks from the end of the 8th century and became consolidated during the 12th century thanks to the fame of the Christian leaders in the Holy Land, in particular Baldwin I of Jerusalem, brother of Godfrey of Bouillon, and through the literary diffusion in the Carolingian epic, for example in the Chanson de Saisnes.

The Germanic name is composed of baltha- ("bold, brave") and wini ("friend, companion"), with an approximate meaning of "brave friend" or "the one who has brave friends". Badino in particular is typical of western northern Italy, with strong presence in Turin, Cuneo, Alessandria, Imperia, Savona and Genoa. It probably derives from a contracted form of the medieval name Balduinus / Baldovino, or from an aphaeretic hypocoristic form of Germanic names such as Theobaldus.

Within the same onomastic group, other variants are identified in Italy: Badini, widespread in the Biella area, the Verbano and various areas of Lombardy, especially in the province of Brescia, with records also in Bologna, Florence, Arezzo, Grosseto and Lazio; Badoino, uncommon and peculiar to the Savona area; Badovini, extremely rare and characteristic of the province of Piacenza; Baduini, almost non-existent, with some records in the Milan and Bergamo areas; Baduino, even rarer, limited to the Alessandria area and areas of Liguria; Baldovini, very rare, with main presence in Rimini and Pesaro; Baldovino, with historical clusters in Piedmont, especially in Alessandria and Asti, one of the forms closest to the original anthroponym; Balduini, a Latinised form of Balduinus, with small clusters in Pesaro and Rimini; Baldoin, widespread above all in the Veneto, as an early Franco-Venetian form; and Bauduin, of Frankish origin, documented in Piedmont and in the Naples area.

E. Rossoni derives it from an abbreviated form of the medieval name Balduinus or Baldovino, or from an abbreviated affectionate form of medieval Germanic names such as Theobaldus.

V. Blunda presents it as a Sicilian surname of Germanic root, derived from the personal name Badin, a diminutive form linked to the root badu ("combat, struggle"), a productive element in Lombard anthroponymic compounds such as Baduardo or Baduino. He recalls that the warrior quality was a central value in Germanic anthroponymy, where names exalted the martial virtues of the bearer. The variant Badani reflects the usual vowel oscillation of the Sicilian dialect.