E. Rossoni proposes that the surname would derive from the medieval term campese or campise, used to designate cultivable lands, as documented in a text of 1258 in Afragola. According to Rossoni, the cluster peculiar to the Vicenza area could come from the place name Campese di Bassano. He also records related variants: Campese in the Naples area and in the Sassari area (especially in Gallura), Campesi in Sardinia, Campise in Calabria, and Campisi in Sicily and in the Reggio Calabria area.

V. Blunda disagrees with that interpretation for the Sicilian case and warns that associating the surname with the Italian campesi —related to "field"— is a false etymology. For Blunda, Campisi is a surname of Sicilian dialectal origin that derives from the dialectal word campisi, meaning "soldier armed with a bow". The term originally designated the archers who made up the urban and baronial militias of Sicily during the late Middle Ages, a period in which they had special prominence during the Sicilian Vespers of 1282 and the later conflicts between Angevins and Aragonese for control of the island.