Diphilus (born c. 360–350 bc, Sinope [now in Turkey]) was a major poet of Greek New Comedy and a significant influence on the Roman playwrights Plautus and Terence.
Diphilus lived most of his life in Athens, and his death was commemorated there with a funerary epitaph. He is believed to have written more than 100 comedies, of which 137 fragments and 63 titles have survived. His themes often came from daily life (Painter, Parasite, etc.), although a play’s title may not have referred directly to its characters or plot. (For example, Heracles was apparently about a man who wanted to imitate the hero.)
Plautus reworked an unknown play by Diphilus for his Rudens and used Diphilus’s Men Casting Lots for his Casina and Diphilus’s Men Dying Together for his lost Commorientes. In Adelphoe (“Brothers”) Terence used a scene from Men Dying Together that Plautus had not translated for Commorientes. Diphilus’s use of metres beyond those typical for New Comedy may have influenced Plautus’s decision to use many different metres in his Roman versions of the works.