The surname Bedetti and its variants —such as Bedin, Bedini and Bedino— constitute an autonomous group within Italian onomastics, without direct relation to Benedetti, although they are sometimes confused in the records. According to the information compiled by Surnames in Italy, its origin is multiple: it may derive from the personal name Beda (of possible Norman or Celtic root), from dialectal forms of the Latin cognomen Betto, or even, in specific cases, from a nickname linked to the dialectal term bèda ("chard"), of Latin origin (beta). These hypotheses explain the diversity of forms and the regional distribution of the surname, concentrated mainly in northern and central Italy.

Along the same lines, E. Rossoni confirms this plurality of origins, noting that Bedetti may derive from affectionate forms of Beda or from its Celtic antecedent Betha, as well as from dialectal variants of the name Betto. He also considers the possibility that, in some cases, the surname functions as a diminutive of Beda from the dialectal term bèda. He also provides a precise geographical distribution: Bedetti is concentrated between Modena, Bologna and the Rimini–Pesaro–Ancona axis; Bedin is typical of Padua and Vicenza; Bedini predominates in central Italy; and Bedino is characteristic of the Cuneo area.

Taken together, the various interpretations agree in pointing to a complex anthroponymic origin, with Celtic, Latin and dialectal influences. The limited distribution of these variants reinforces the idea of a specific regional development, unlike more widespread surnames, and shows how a single etymological core could evolve into different forms according to the geographical area and local linguistic transformations.