The authors agree that this surname is of toponymic origin, derived from place names such as Montalto and Montaldo, present in various localities of Italy. E. De Felice notes that the form Montalto corresponds to localities of southern and central Italy, while Montaldo is associated mainly with Piedmont and Liguria, being very frequent in Genoa.

F. Miranda proposes as the most probable origin the place name Montalto Uffugo, in the province of Cosenza, or else Montalto di Castro, in the Viterbo area, without ruling out other place names of the same form distributed throughout the Italian peninsula. Miranda highlights a notable presence of the surname in Sicily, where it is documented in all its provinces, especially in Trapani, Palermo, Catania and Syracuse, and in the Enna area in localities such as Agira, Enna, Piazza Armerina, Villarosa, Aidone and Regalbuto. He also notes its diffusion in Calabria, Lombardy, Lazio, Piedmont, Emilia-Romagna, Tuscany, Campania, Liguria, Puglia and Veneto.