From the first name Salvo or Salvio, a good wishes name meaning "saved through Faith".

E. De Felice, E. Rossoni and F. De Laurentiis agree that the surname was formed from the names Salvo or Salvio, which continue the late Latin personal names of Christian devotion and auspicious value Salvus and Salvius, derived from salvus ("safe [in God]").

De Felice specifies that the base may also be, at least for Tuscany, the hypocoristic Salvi —already attested in the Libro di Montaperti of 1260 in Florence— of Diotisalvi. He adds that Salvia, in the peninsular south, may also be formed from the place name Salvia, which was until 1879 the name of the present-day Savoia di Lucania, in the province of Potenza.

Rossoni suggests that all these forms derive, directly or through derived forms, from the Gens Salvia, from the name Salvius —documented in the Epitome De Caesaribus with Salvius Otho— or from the medieval name Salvus. Rossoni distinguishes the variants: Salvi is very diffused throughout the centre-north; Salvini seems native of Tuscany, with a possible presence in the Rome area and in Lombardy; Salvia has nuclei in the Naples and Potenza areas and in Sicily; Salvio seems typically of the region of Campania; Salvioli has a presence in the Modena and Salerno areas; Salvioni has a nucleus in the Bergamo, Milan and Como areas, and another in Rome; Salvo is specific to Sicily; Salvoni has nuclei in the lower Brescia area, in Tuscany, in the Ancona area and between Rome and Latina.

De Laurentiis agrees on the etymology and on the toponymic base for Salvia in the peninsular south. He adds that the surname is diffused throughout Italy.