The surnames Marco, Marchetti, Marchini, Marcon, De Marchi and their variants make up a broad family of surnames of a patronymic type, derived from the ancient Roman praenomen Marcus, whose meaning is "dedicated to the god Mars" (Mars Martis). This name spread throughout Italy not only through its use as a personal name, but also through the prestige and the cult of Saint Mark the Evangelist —that is, through devotion to Christian martyrs, as with the surnames derived from the names Pietro, Giacomo, Giovanni, Domenico and Antonio. Marco spread particularly in north-eastern Italy, being the patron of the city of Venice and of the old Venetian Republic. Various authors have approached these surnames from different angles:

• A. Bongioanni stresses the Latin root mar which links Marco with Marte and Mario, and indicates that from this name numerous surnames arise, such as Marchetti, Marchesi, Marchettiello and Marchesini, among others. He also warns against etymological errors, such as attributing the origin of Marchettano to the Friulian marçhadant ("merchant"), which he considers incorrect.
• E. De Felice offers a systematic classification of variants, altered forms and compounds. He identifies as derivatives of Marco: Marchetti, Marchetto, Marchioli, Marcolini, Marcato, Marconati, Marcolla and Marcotti, among many others, and specifies that Marchi is frequent in northern Italy, while forms such as Marchetta, Marchitto and Marchitiello are typical of the south. The Slavic patronymics such as Marcovich are concentrated in border areas such as Friuli-Venezia Giulia.
• E. Rossoni carries out a detailed analysis of the territorial distribution. He singles out Marchet as typical of Feltre (Belluno) and Marchetta as proper to the south and to some areas of Rome and Piacenza. Marchetti, by contrast, is found throughout central and northern Italy. Rossoni traces historical documentation such as the composer Marchettus Paduanus (1270–1335) and 17th-century judicial testimonies in Milan which already record the surname Marchetto. Marcon, for its part, appears as a surname linked both to the place name of the same form in Veneto and to families of Piedmont. He also details the presence of variants such as Marchini (the Prato and Terni areas), Marchi (in Vicenza and Treviso) and Marcotti (in Piacenza).

In sum, these surnames not only share a common etymological origin in the name Marco, but also reflect patterns of regional distribution, internal migratory processes and dialect adaptations that have enormously diversified their forms. The wealth of variants such as Marcolini, Marcato, Marcocci, Marchiol, Marcucci or Marcuzzi, together with their documented presence from the Middle Ages onwards, makes them a model of the evolution of names into stable surnames.

Derived forms