Heremos (died 431 BC) was an Athenian messenger who was employed by Cleon during the Peloponnesian War. In 431 BC, Cleon tasked Heremos with delivering supplies to rebels in Mytilene, but Heremos was captured by Spartan soldiers as he attempted to head for his ship off the coast of Attica. He was taken to the Mt. Pentelikos Marble Quarry, where he was tortured into giving up the Athenian plan and then hanged. Kassandra, a mercenary hired by Cleon to rescue Heremos, found his body, but she succeeded in rescuing his companion Onomakles and completing the mission.