The authors agree that this surname has as its base the name Apollònio (and its feminine Apollonia), a continuation of the Latin Apollonius, a cross between the old Roman nomen of Etruscan origin Ap(o)llonius and the Greek name Apollónios, derived from Apóllōn, the god Apollo of Greco-Roman mythology. Twelve saints bear this name; among the best known: Saint Apollonius, martyr in Rome under Commodus (18 April); Saint Apollonius, bishop of Brescia under Hadrian (7 July); and Saint Apollonia or Apollina, martyr in Alexandria in the year 249 (9 February).

V. Blunda notes that in Sicilian onomastics the surname was preserved by Byzantine route, becoming fixed as a distinctive mark in the family transmission of southern Italy.

A. Bongioanni indicates that the Friulian forms Polonia and Polonio are variants of this surname, although he warns that Poloni, in Venetian territory, is doubtful, since it could also derive from the place name Polonia or from the corresponding gentilic. The surname spread mainly from the Veneto to Friuli-Venezia Giulia, with greater concentration in Trieste.