The sources differ in the origin of this surname. E. Rossoni proposes that it could derive, directly or through affective modifications, from the Latin cognomen Galba, name of the Roman emperor Servius Sulpicius Galba —the very brief successor of Nero—, or from Galbus, of which Licinius Galbus is cited as an example.

Another source, on the other hand, proposes an origin in the Arabic root g-l-b (gialaba), meaning "to bring something from outside to sell, to import", whence derives giallāb, "importer, merchant". It also notes its kinship with the word giulebbe, a sweet drink kept fresh made from rose water.

As for its geographical distribution, Rossoni indicates that the form Galba is extremely rare and seems peculiar to the Piacenza area. Galbi and Galbino are practically unique. Galbini appears in small zones of Cava de' Tirreni, in the Salerno area, and in the Bari area. Galbo, for its part, is concentrated in Caccamo, Palermo and Termini Imerese, in the Palermo area, and in Alcamo in the Trapani area.