The consulted works concur in tracing this surname primarily to place names bearing the form Lama, found in various localities across the Italian peninsula. The localities identified include Lama di Marzabotto and Lama di Reno e di Setta in the area of Bologna, Lama Mocogno in the area of Modena, Lama Polesine in the area of Rovigo, and places named Lama in the areas of Arezzo and Pavia. It is also recorded, more broadly, that the place name Lama is quite common throughout Italy, which accounts for the surname's dispersal across the peninsula. The greatest concentration is found in Emilia-Romagna.

E. De Felice contributes an early documentary attestation: as far back as the year 977, an "Adelgari de Lama" is mentioned in Bari, placing this surname among those with the oldest recorded evidence in Italian onomastics.

E. Rossoni introduces a second, independent line of origin: a possible derivation from the Late Latin family name Lamia, belonging to the gens Aelia and connected to the mythical Lamus, son of Poseidon and legendary founder of Formia according to Greco-Latin tradition. Among its historical bearers, Rossoni recalls Lucius Aelius Lamia, consul of Rome in the year 3 AD and mentioned in Cicero's De Oratore. Rossoni further notes a later reference in the Tuscan writer Giovanni Lami (1697–1770), in whose case the variant form Lami is already documented in the eighteenth century, with a presence in Tuscany, the area of Modena, and Rome.