The consulted works concur in identifying Marino as one of the ten most common surnames in Italy. Its origin may follow one of two main paths. The first is etymological: the name derives either from the Latin personal name Marius — the source of the Italian given name Mario — or from the Latin adjective marinus, meaning "of the sea." The second path is topographic: in some cases the surname may derive from a place name, since localities called Marino are frequent in southern Italy, all sharing a connection with the sea or coastline; this origin would suggest that the original bearers lived near the coast.

A. Bongioanni and G. P. Holmes present identical content on this surname. Both note that numerous Italian noble families have carried the name Marino, and both cite the armorial of Sicily, which records a Marino family originally from Genoa — emigrants from Sicily who for a long period held prominent offices in the Italian Republic. As this information falls within the category of theories about specific families, it is noted here only for completeness and does not form part of the etymological or geographic analysis.

It is also recorded that the surname belongs to a broader family of related forms, including Marini, Marinetti, Marinaccio, Marinazzo, and Marinelli, all sharing the same root.