The surname Boldrini and its variants —such as Boldrin— have an anthroponymic origin of Germanic root, with possible later dialectal developments. According to E. Rossoni, they derive from the medieval name Boldrinus, formed from names ending in -boldo or -poldo (such as Uboldo or Leopoldo), which in turn come from the Germanic element bald ("bold, brave"). This type of name was very frequent in the Middle Ages and transmitted valued qualities such as strength or courage.

Rossoni also documents the historical presence of this name, for example with Boldrino da Panicale, a famous mercenary captain of the 14th century, and with the engraver Nicolaus Boldrinus in Venice in the 16th century, which shows its antiquity and diffusion in northern Italy. From the geographical point of view, he indicates that Boldrin is typically Venetian, while Boldrini has spread throughout the centre-north.

He also mentions other possible interpretations: a derivation from the Venetian term boldro ("swollen") or from the Germanic name Waldhari (from waltan, "to govern", and heri, "army"), meaning "chief of the army", which shows the complexity of its evolution.

For his part, F. De Laurentiis proposes a different reading, linking the surname to the dialectal term boldra, understood as "place of confusion or disorder", which would suggest a nickname origin in some cases.

Taken together, the various interpretations agree in pointing to a multiple origin, predominantly anthroponymic of Germanic root, with possible dialectal influences that gave rise to regional variants within northern and central Italy.