The authors agree that the surname derives from the given name of Germanic origin Sinibaldus, of Lombard tradition. E. De Felice details its documentary evolution: it appears in Italy from the 8th century as Sichipaldus, then from the 10th century as Sigebaldus, and from the 11th century as Sigembaldus and Senebaldus. The Germanic personal name is formed by the elements *sigin- and *sin-, secondary forms of *sigu-, with the meaning of "victory."

E. Rossoni places the main zones of presence of the surname in Lazio and Umbria, with additional nuclei in the Bergamo area and in Veneto. Rossoni documents the form Sinibaldus on a tombstone of the year 1200 and in texts of the 14th century. Among the historical bearers he mentions the sculptor and architect Bartolomeo Sinibaldi, known as Baccio da Montelupo (1469–1535).