The authors agree that the surname derives from the Latin personal name Boetius, linked to the figure of Severinus Boethius, Latin philosopher and man of letters of the 6th century, adviser to the Ostrogothic king Theodoric and later imprisoned and executed.

A. Bongioanni notes that the surname is documented in Friuli, specifically in Ciseriis, a locality of Slavic population largely Friulianised. He warns that it would be legitimate to doubt whether the surname derives directly from the famous medieval philosopher, although he acknowledges that Boethius was venerated as a saint in the diocese of Pavia from time immemorial and was formally recognised as such by Leo XIII in 1879. He also notes that the Piedmontese surname Poesio could share this same origin.

E. Costantini provides concrete documentation: the surname appears in Gemona at least from 1547, in a text that mentions al excellente ms Sebastiano boetio doctor phisico de gimona. He notes its presence also in Povoletto and Udine.