Diodorus of Tyre was a Greek philosopher of the 2nd century BCE, active around 110 BCE. He was a member of the Peripatetic school, the tradition founded by Aristotle. Diodorus studied under the philosopher Critolaus and later succeeded him as the head, or scholarch, of the Lyceum in Athens. This position placed him in the direct line of succession from Aristotle himself. He was a contemporary of other major philosophers like Carneades and Diogenes of Babylon.

Only one work is attributed to Diodorus, a lost treatise titled On the Philosophy of Plato. This title suggests he engaged critically with Plato's ideas from his own Peripatetic viewpoint. No other writings by him are known to survive.

Diodorus is historically significant primarily as a documented leader of the Peripatetic school during the Hellenistic period, a time when its prominence was declining. His succession helps scholars date the often unclear timeline of the school's leadership. The title of his lost work indicates an ongoing philosophical dialogue between the Peripatetic and Platonic traditions. Furthermore, the Roman writer Cicero later mentioned Diodorus as an example of a philosopher who remained intellectually vigorous into old age, which helped preserve his name in later cultural memory.