The surname Amantea and its variants —such as Mantia or the matronymic form La Mantìa— have a clearly toponymic origin and are linked to the town of Amantea (province of Cosenza, Calabria). According to E. De Felice, the surname is formed from this place name, whose local pronunciation (Amantìa, Mantìa) gave rise to various variants, especially in southern Italy.

As for its diffusion, E. De Felice notes that the surname is typical of Calabria, but has also spread to the Neapolitan area and to Sicily, where it shows high frequency, particularly in its form with the feminine article (La Mantìa). This wide diffusion is explained by the strategic importance of Amantea during the Middle Ages, when it was a relevant military and naval centre under Byzantine, Saracen, Norman and Swabian rule.

For his part, E. Rossoni confirms this origin, indicating that the surname derives from the place name Amantea and from its archaic form Amantia, reinforcing the geographical interpretation.

Taken together, both interpretations agree in pointing to an origin linked to territorial provenance, where the surname Amantea preserves the direct reference to a locality of great historical relevance in southern Italy, whose influence favoured its wide diffusion.