The toponym Salernum, rather than from the traditional "salum", that is sea, derives more probably from the prelatin hydronymy base "sal", that is channel, watercourse, or, rather, marsh (Sal-ernum, place of marshes, once existing near the it costs).

Regarding the origin of the name, among other hypotheses, Antonio Mazza wrote that Patriarch Noè came twice to Italy, and the second time he lived there for thirty-three years; that falling in love with the waters of the Irno river, he ordered his eldest son to embellish its right bank with a city; that out of devout obedience Sem threw the first stone and, after several years, Salt son of Arfaxad, and great-grandson of Noè, accomplished the noble city, giving it his name coupled to the Irno. Thus removing the contradiction between the acts of SS. Martiri Fortunato, Gaio e Ante, and the name Salerno: Sale, Mazza says, "filium Arfaxad, Noe pronepotem Salernum condidisse, illique nomen dedisse: nec contradiclionem implicai, in festo Martyrum Fortunati, Caii et Anthes decantari, Civitatem esse fundatam a Sem. Exordium fundationis debet".

Anyway the toponym Salernum pre-existing to the original Latin colony of 197 BC because in 216 BC a so-called "oppidum Salerno" sided with the Romans to fight, in the 2nd Punic War, Carthaginians, All the allies who participated in the battle of Canne have been reported in libro VIII dei Punica by Silio Italico: among these the brave of the pugnacious Salerno stand out: this brave alliance was rewarded by the Romans victorious they attributed to Salerno the status of a Roman citizen colony and the title “Ordo Populusque Salernitanus”.