The authors agree that this surname derives from the medieval name Pace, of Latin origin (pax, pacis), given to a child who was wished to bring peace and tranquillity to the family, with a Christian sense also linked to the cult of some saints.

E. De Felice notes that the name continues in part the Latin signum of the late imperial period Pax Pacis, in turn a calque of the Greek Eirène, although for the most part it is a medieval auspicious and gratulatory creation arisen directly from the Romance noun pace. He adds that in some cases it may be the aphetic hypocoristic of the medieval name Bonapace.

F. Miranda specifies that the surname, together with its variants —Pace, Pasi, Pase, Pasio— and derivatives —Pacelli, Pacini, Paciotti, Paciullo, Pacenti, among others—, is spread throughout the Italian peninsula, with a greater presence in the Marche, Tuscany, Emilia-Romagna, Lazio, Umbria and Lombardy. In Sicily it appears especially in the Agrigento, Caltanissetta, Trapani, Catania, Palermo and Enna areas.