Panyassis of Halicarnassus was a Greek epic poet of the 5th century BCE. He was a relative of the historian Herodotus and a member of a distinguished Halicarnassian family. He was executed by the tyrant Lygdamis around the mid-5th century BCE, likely for political opposition, with his period of greatest activity placed around 480-460 BCE.

His two major works survive only in fragments. The Heraclea was a 14-book epic detailing the deeds of Heracles. The Ionica was a historical or genealogical epic in elegiac couplets concerning the foundation of the Ionian cities.

Panyassis was highly esteemed in antiquity, ranked by some critics with Homer and Hesiod. His Heraclea was a seminal, systematic treatment of the Heracles myth cycle, influencing later mythological poetry. He represents the late archaic epic tradition and the intellectual milieu of Halicarnassus that produced both epic poetry and history.