Antoninus Liberalis is known solely as the author of the Metamorphoses. His precise dates, birthplace, and biographical details are unknown, though his name suggests a Roman context. He is traditionally placed in the late second or early third century CE, within the period of the Second Sophistic. His work indicates a learned, scholarly familiarity with earlier sources, but no specific personal information survives.

His only extant work is the Metamorphoses, a compilation of forty-one brief transformation myths drawn from earlier Hellenistic sources. Antoninus Liberalis is a significant compiler and transmitter of mythological narratives. His Metamorphoses preserves variants of myths and serves as a crucial witness to the content of now-lost Hellenistic works, particularly those of Nicander and Boeus, whom he cites. The collection reflects the antiquarian interests of his era and is a valuable source for understanding later Greek mythography.