E. De Felice notes that the base of this surname is the word capo, which in Italian means "head". In its simple form, Capo is not very frequent and appears limited to the Veneto area and the Naples region. De Felice explains that this term gave rise to numerous nicknames and names linked both to physical traits of the head —as in Capobianco, Caporosso or Capotorto— and to intellectual or character traits, as in Capotosto. He also notes that Capone and Caputo could refer to the one who has "a big head" or to the one who is "stubborn or slow to understand".

E. Rossoni provides a complementary perspective: he considers that Capo would be an abbreviated form of surnames or nicknames composed of capo followed by an adjective; for example, from Caporizzo one would arrive at Capo. Rossoni places its main presence in Campania, especially in the Salerno area, with more specific areas in the Venice area and in the Trapani area, in Sicily.

Both authors agree that the surname is inserted in a broad lexical family articulated around the term capo, with derivatives and compounds distributed mainly in southern Italy, although the simple base form has a more limited and scattered presence.