Hermocles of Cyzicus is an obscure poet. No biographical details of his life are recorded. His identification derives solely from his association with a single surviving work, which places him in the early 3rd century BCE.

His sole surviving work is a paean, preserved as a fragmentary inscription. This song of praise is addressed not to a traditional deity but to the Hellenistic king Demetrius I Poliorcetes. It celebrates Demetrius's entry into Athens in 291 or 290 BCE, hailing him as a divine savior.

The paean is a significant document for understanding the development of ruler cults in the Hellenistic period. It exemplifies the religious and poetic language used to honor monarchs, blurring the line between mortal ruler and divine figure. The fragment provides direct insight into the ceremonial propaganda of early Hellenistic Athens under Antigonid influence.