V. Blunda notes that this surname comes from the Greek eusebḗs, "pious", composed of eu-, "well", and sebō, "to revere". Its adoption as a given name was sustained in the Byzantine hagiographic tradition, especially through the figure of Saint Eusebius of Caesarea.

A. Bongioanni agrees on the Greek origin and notes its equivalence with the Latin Pius. He highlights that the name was borne by numerous saints, among them three linked to Lombardy, although the most venerated are Saint Eusebius, bishop of Caesarea and martyr in the year 309, and Saint Eusebius, bishop of Vercelli, celebrated on 1 August. The popular Piedmontese form of the name is Söbi.

Bongioanni also traces a series of surname derivations of regional reach. In the Veneto, the place names Sanzibio —equivalent to San Eusebio— and Zevio open, according to the author, a chain of etymologies: the Emilian place name Zibello and the surnames Zibelli, Zivelli, Gibelli, Civelli and Cipelli. The Neapolitan name Eusapia —which he links with the Dantean Sapia— would be for Bongioanni a deformation of Eusebia, and from there would derive the Piedmontese surnames Sapelli, Sapetti, Sapegno and Zeppegno; the interchange between b and v peculiar to some dialects would explain in addition the forms Savi, Savio, Savelli and Savioli.

As for the Tuscan surnames Zobi and Zóboli, Bongioanni considers a derivation from Zanobi more probable than from Eusebio. Finally, he proposes that from the name Eusebiano could come the surname Zobianco —dialectal form Söbian— and the place name Zubiena, in the Biella area, an old Eusebian diocese.