Diogenes of Babylon was a Stoic philosopher who lived during the 2nd century BCE. Originally from Seleucia on the Tigris, he moved to Athens, where he studied under the influential Stoic thinker Chrysippus. He later became the fifth head, or scholarch, of the Stoic school in Athens.

He is historically significant for being a member of the famous "Philosophers' Embassy" sent from Athens to Rome in 155 BCE. The group, which included philosophers from other schools, aimed to appeal a political fine. Their speeches, particularly on topics like justice, made a strong impression on Roman listeners and are seen by modern scholars as a key early moment in the introduction of Greek philosophy to Roman elite culture.

Diogenes was a prolific writer, but none of his works survive complete. Based on reports from later authors, he wrote on core areas of Stoic thought, including ethics, logic, rhetoric, and the nature of the gods and divination. As a scholarch, his primary role was to preserve and teach the doctrines established by his predecessors. His ideas, especially on language and ethics, influenced his student Antipater of Tarsus and were later discussed by Roman writers like Cicero.