This name can also be found in its Portuguese form, Túlio, where the syllabic stress is on the "u". It is still relatively common in places such as Brazil. [noted -ed]
I have heard two origins for the name Tullio, which is my surname. The first is that it derived from the proto-Latin or Etruscan word "tullus", which meant a spring. The progenitor of the Clan Tullius perhaps lived by a spring. I have also heard that it was a gesture made by the father of a new-born male child in recognition of his legitimacy.Tullius can be found among the Latins, the most famous bearer of the name among Romans was, of course, Marcus Tullius Cicero, and also among the Volscians, whose king was Attius Tullius. Servius Tullius was a king of the Romans.Tullio Carminati (1894-1971) was a famous Italian actor (see "The Cardinal").Francesco Antonio Tullio (1660-1737) of Naples wrote the libretto for Scarlatti's opera "Il Trionfo d'Onore."