Hermesianax of Colophon was a Hellenistic elegiac poet active around 300 BCE. A pupil and friend of the philosopher-poet Philitas of Cos, he was connected to the scholarly circles of early Alexandria. Ancient sources, including Athenaeus and the Suda, provide minimal biography but note his epithet "the singer of loves."

His three works survive only in fragments. The most notable is the elegiac poem Leontion, in three books, dedicated to his mistress. The others are the lost historical poem Persica and a prose work On the Poets of the Distich.

Hermesianax is significant as a representative of learned Hellenistic elegy. A 98-line fragment of Leontion, preserved by Athenaeus, showcases his cataloguing technique. It presents mythical love stories that claim famous past poets and philosophers as lovers, thereby framing his own passion within literary tradition. This inventive approach influenced later poets like Propertius.