E. De Stefani proposes that this surname originated as an affectionate form of the Friulian given name Matìe (equivalent to Mattia, from the Latin Matthaeus), through the suffixed form Matiùs, from which the shortened variant Tiùs was formed, pronounced with the palatalised t and written as Chius. The name Mattia comes from the Hebrew mattathai, which meant "gift of God" (from mattat, "gift", and Ya or Yahweh, "God"). Over time, this form became a surname. De Stefani documents it in Friuli and in particular in the Carnia —a mountainous region of northern Friuli, in the province of Udine—, where, according to oral tradition, the first bearers would have arrived around the 15th century from the Gail valley, in neighbouring Carinthia.

E. Rossoni, on the other hand, places the surname in a completely different geographical area: the provinces of Reggio Emilia and Parma, with an especially marked presence in Poviglio. According to Rossoni, it could derive from an archaic dialectal nickname referring to the one who operated the small sluice gates of the irrigation canals.

The divergence between the two authors suggests that the surname presents independent origins in different regions of Italy, with etymologies and historical contexts that bear no relation to each other.