Antonino Liberal (in Latin Antoninus Liberalis) was a Latin writer in the Greek language of whom there are hardly any biographical references. He is generally placed in the second or early third century AD. c.

The only preserved work of his is Metamorphosis (Metamorphoseon Synagoge, Μεταμορφώσεων Συναγωγή, literally "Collection of metamorphosis"), a prose work that collects forty-one stories of Greek mythology in which transformations of characters carried out by the gods appear. Most of these stories have as their source works now lost from the Hellenistic period, especially Beo's Ὀρνιθογονία / Ornithogony (3rd century BC) and Nicander of Colophon's Metamorphoses or Ετεροιούμενα. It is not ruled out that some of them were the invention of Antoninus himself. Metamorphoses were a common theme in the mythography of the time, with works such as Ovid's Metamorphoses and Apuleius's Golden Ass (or Metamorphoses).

Only one manuscript of the work has survived: the Palatinus graecus Heidelbergensis 398, from the late 9th century, which, as its name suggests, is now in the Palatine Library in Heidelberg. Guilielmus Xylander first edited the text in 1598 in Basel. Since then, the manuscript has lost some of its leaves, the contents of which we only know from the Xylander edition.

Antonino Liberal's work is esteemed more for the wealth of mythological information it contains than for his style, which one of his translators describes as "dry, coarse, rough."