Dinarchus was a professional speechwriter who worked in Athens during the late 4th and early 3rd centuries BCE. Originally from Corinth, he moved to Athens to study rhetoric. As a resident foreigner, he was not allowed to speak in court himself, so he earned a living by writing forensic speeches for Athenian citizens to deliver. His career flourished under the Macedonian-supported government of Demetrius of Phaleron. After democracy was restored in Athens in 307 BCE, Dinarchus was accused of collaboration, exiled, and had his property seized. He lived in exile for about fifteen years before being permitted to return to Athens around 292 BCE.

He was a prolific writer, credited in ancient times with over 160 speeches. Only three of his orations survive in full, all from the same major political scandal known as the Harpalus affair in 323 BCE. These speeches are Against Demosthenes, Against Aristogeiton, and Against Philocles. The authenticity of a fourth surviving speech is considered doubtful by scholars.

Dinarchus is historically significant as the last of the ten canonical Attic orators. His surviving works are important primary sources for understanding Athenian politics and law in the turbulent period following the death of Alexander the Great. According to ancient critics, his style was competent but heavily imitated greater orators like Demosthenes, leading some to view his work as derivative. Nonetheless, his speeches provide valuable insight into the practice of legal speechwriting and the functioning of Athenian courts under foreign influence.