Scholars agree that Laconi is a toponymic surname of Sardinian origin, derived from the name of the town of Laconi, located near Nuoro in Sardinia.

E. De Felice and E. Rossoni propose a second, non-exclusive line of origin: that certain lineages may be connected to an older root linked to the ancient Greek people of the Laconians, from the region of Laconia in the Peloponnese. They support this hypothesis by pointing to the existence of the medieval Sardinian family Lacon-Serra, documented as early as the tenth century. In their view, the surname may thus reflect both a straightforwardly Sardinian geographical origin and a possible historical inheritance of classical tradition in certain lineages.