Dimnus (Ancient Greek: Δίμνος) of Chalastra in Macedonia was hetairos of Alexander. In autumn 330 BC, he formed a conspiracy to murder the king. Dimnus revealed to his eromenos Nicomachus the names of the conspirators (Demetrius, Peucolaus, Nicanor, Aphobetus, lolaus, Dioxenus, Archepolis, Amyntas). But the plot was divulged by Cebalinus, who learned of the details from his brother, Nicomachus.