E. De Stefani explains that this surname arose as a shortened form of Antoniutti, derived from the given name Antonio with the Friulian diminutive suffix -ut, with the original sense of "little Antonio". The Latin name Antonius, of possible Etruscan origin, spread widely in Europe in good part thanks to the figure of Saint Anthony of Padua, and over time became a surname. E. Rossoni agrees in noting the Friulian diminutive origin, specifying that it is a form with the loss of the initial syllable of the name Antonio.

Geographically, both authors agree that the surname is concentrated in the Udine area, with a presence in localities such as Ragogna, Rive d'Arcano, San Vito di Fagagna, Tarcento and the city of Udine itself. De Stefani also adds Bertiolo, Buia and Gonars, and notes its rooting in the Carnia —a mountainous zone of northern Friuli— specifically in Pradumbli, a frazione of Prato Carnico, and in Amaro from 1823. Rossoni, for his part, records the variant Toniutto in Palazzolo dello Stella and Latisana, also in the Udine area.