Demonicus was an Athenian comic poet of the Classical period, active in the 5th or 4th century BCE. He worked within the tradition of Old Comedy, as practiced by Aristophanes. No biographical details about his life are known. Ancient sources attribute two comedies to him: The Arrhephoroi and Philargyros. Both plays are now lost. The title The Arrhephoroi refers to the young girls who served in the cult of Athena Polias, suggesting a mythological or religious theme. Philargyros translates as "Money-Lover," indicating a plot likely centered on greed. Only a single brief fragment from The Arrhephoroi survives. Demonicus is considered a very minor figure. His significance lies primarily in his inclusion in historical catalogs, which helps demonstrate the breadth of comic production in ancient Athens beyond the few major playwrights whose complete works survive. The titles of his lost plays offer small insights into the variety of subjects treated in Old Comedy.