F. De Laurentiis notes that Amoruso is a variant of Amoroso, very frequent in southern Italy, especially in Puglia. The surname derives from the affectionate name amoroso, with the sense of "full of love, in love, much loved, beloved", and is documented from the 11th century in Molfetta and other southern centres under the Latinised forms Amorusius and Amorusus.

F. Miranda agrees that the surname, together with the variant Amoroso, derives from the Late Latin Amorosus or Amoriusius, with the same meaning, and confirms its documentation from the 11th century in Bari and Molfetta. Miranda adds that Amoruso extends throughout central-southern Italy, with notable presence in Puglia, Campania, Calabria, Lazio, Molise, Basilicata, Sicily and Tuscany, among other regions. In Sicily it is recorded especially in the areas of Catania, Enna and Messina. The variant Amoroso, for its part, shows greater concentration in Campania and Sicily, with presence also in Lombardy, Calabria, Abruzzo, Lazio, Puglia and Piedmont.