E. De Felice notes that this surname originates from the name Erminio, taken up in the Renaissance from the Latin nomen Herminius, of probable Etruscan origin, and which over time became a surname.

E. Rossoni broadens this perspective by proposing that the surname could derive from the Roman patrician gens Herminia, of probable Oscan or Etruscan origin, or from the Roman gentilic name Herminius. Geographically, Rossoni specifies that the surname is distributed mainly in Tuscany —with special presence in the Florence, Arezzo and Siena areas—, in the south of the Marche, in Umbria —particularly in the Terni area— and in the north and centre of Lazio, with concentration in Rome. The variant Erminio, on the other hand, is very rare and appears in a specific way in Andria, in the Bari area.