The authors agree that this surname derives from the personal name of Germanic origin Audha, whose root aud or od points back to the meaning "possession, wealth, power". It is a hypocoristic without suffix of compound names with the first element *audha-, which in Italy gave rise to forms such as Oddo, Odo, Oddone, Odone and, in parallel, Otto and Ottone.

E. De Felice notes that this set of forms reveals a double tradition in Italy: Lombard for the type with -d- or -dd-, and German —Alemannic or Bavarian— for the type with -tt-, established in the Italian peninsula from the 10th century with the emperors Otto I, II and III. F. Miranda specifies that all the variants —Oddi, Oddone, Oddoni, Odoni, Otto, Ottone, Ottoni— derive directly or through hypocoristics from the Franco-Lombard name Oddo.

As for its geographical distribution, De Felice places it mainly in northern and central Italy, with a greater frequency in Piedmont and Liguria, and a presence also in Sicily. Miranda confirms its notable rootedness in Sicily, where it is recorded in numerous localities of the Trapani, Palermo, Messina, Syracuse, Agrigento, Catania and Enna areas, besides Lombardy, Piedmont, Liguria and specific areas of Lazio, Tuscany, Veneto and Emilia-Romagna.