The surname Pirri/Pirro presents diverse origins according to the Italian region from which it comes. It is generally considered derived from the Roman name Pyrrhus or the Greek Pyrrhos, widespread in southern Italy from ancient times and later documented in areas such as Acerra (Naples) in the 15th century and in the province of Rome during the 16th century.

In Calabria, some lines could have a different origin, related to the dialect word pirru, which means 'robin', probably used as a nickname of a physical or character nature.

In Sardinia, on the other hand, the surname Pirri would have a toponymic origin, linked to the locality of Pirri, today integrated into the Cagliari area. According to the interpretation of the scholar Giovanni Spano, the name could derive from the Greek pyr ('fire' or 'inhabited place') or from the Phoenician pir ('fruit', 'garden' or 'cultivated place'). This geographic origin appears documented as early as the Peace of Eleonora of 1388, where it figures accompanied by the preposition 'de', indicating territorial provenance.

Currently the surname presents historical branches in Sicily (especially Messina), Calabria (Cosenza), Sardinia (Sassari and Cagliari), Lazio, Foggia, Naples and Macerata.