The authors agree that the surname derives from the name Marco, a continuation of the ancient Roman praenomen Marcus (from Mars Martis, with the meaning "dedicated or sacred to the god Mars"). Its spread was driven by the prestige and the cult of Saint Mark the Evangelist, especially in north-eastern Italy, in the regions of Veneto, Friuli-Venezia Giulia and Trentino-Alto Adige, where Saint Mark is the patron of Venice.

E. De Felice notes that Marchi is very frequent in northern Italy, while Marcoz is found in the Aosta Valley, and De Marchi predominates in Lombardy and Emilia-Romagna. Marcovich is concentrated in the Venezia Giulia area. Among the derived forms, De Felice distinguishes apocopated forms and compounds such as Marcolini, Marchioli, Marcolla, Marconati and Marcato, proper to Veneto, as well as Marchetta, Marchitto and Marchitiello, characteristic of southern Italy.