The surname Bini and its whole onomastic family —including forms such as Bino, Binelli, Binazzi, Binaghi, Binasco— have a medieval origin linked mainly to abbreviated personal names. According to the information compiled by Surnames in Italy, they derive from the base Bino, a hypocoristic of names ending in -bino such as Albino, Giacobino or Bernardino. From this root a broad set of surnames developed which, although they share a common core, present diverse regional evolutions: some as patronymics (Del Bino), others as diminutives (Binelli, Binello) and others of toponymic origin (Binago, Binasco).

Along these same lines, E. Rossoni provides a complementary interpretation, noting that in certain cases these surnames could derive from belonging to medieval social structures, such as the Bina, a minor council of twelve elders within the communal organisation. This hypothesis introduces a possible institutional or social origin, distinct from the purely anthroponymic one. He also admits that some forms can derive from female names such as Albina or Colombina, which further broadens the spectrum of possible origins.

Taken together, both perspectives agree in noting that it is not a single origin, but a family of surnames formed from the same core (Bino), which diversified according to local, dialectal and social contexts. This variety reflects the richness of Italian onomastics, where a single element can give rise to multiple surnames with their own historical trajectories.