Diogenes of Apollonia (Greek: Διογένης ὁ Ἀπολλωνιάτης; fl. 5th century BC) was an ancient Greek philosopher, and was a native of the Milesian colony Apollonia in Thrace. He lived for some time in Athens. His doctrines are known chiefly from Diogenes Laërtius and Simplicius.
