F. Miranda explains that the surname derives from the medieval name Boninus, a diminutive of Bonus, which in the sphere of names of good omen takes on the meaning of "good", "of good nature" or "virtuous". Miranda also notes a second hypothesis that associates it with a Celtic-Germanic root bun, with the sense of "owner" or "one who has a house". As examples of its transformation into a surname, he mentions the author Boninus Mombritius in the 13th century and the man of letters Boninus de Boninis, active in the second half of the 15th century in Verona.

G. P. Holmes, for his part, offers a different etymology: he considers the surname a diminutive of the medieval proper name Bona, the feminine form of the same Latin etymon.

As for its geographical distribution, Miranda indicates that the surname is infrequent and is scattered in some regions of Italy, with presence in Sicily —where it records its greatest concentration, especially in the Catania area, the Messina area and the Enna area—, as well as in Lombardy, Piedmont, Calabria, Friuli-Venezia Giulia and Lazio.