Tuone Udaina (1823 – 10 June 1898; Antonio Udina in Italian) was the last known speaker of Dalmatian, a Romance language that evolved from Latin along the eastern coast of the Adriatic Sea.

[1][2] He was the main source of knowledge about his parents' dialect, that of the island of Veglia, for the linguist Matteo Bartoli, who recorded it in 1897.

Bartoli tentatively associated it with burbero, an Italian word for a surly, gruff, or ill-tempered person.

[6] Vegliot Dalmatian was not Udaina's native language, as he had learned it from listening to his parents' private conversations.

[citation needed] Udaina had not spoken the Dalmatian language for nearly 20 years before the time he acted as a linguistic informant.