Phocion was a pupil of Plato and in later life a close friend of the Platonic philosopher Xenocrates. After serving Persia as a mercenary, he was drawn into Athens' efforts to remain independent of Macedonia. In 348 his tactical skills saved an Athenian force sent to crush allies of Philip II in Euboea. He helped Megara (343) and Byzantium (340) defend themselves against Philip, but from about this time he regarded the Macedonians as unstoppable and cultivated diplomatic relations with them in order to avoid outright conquest. Following the death of Alexander the Great in 323, he advised against the Lamian War, though he led the defense against a Macedonian raid into Athenian territory. Sent to sue for peace the next year, he managed to reduce his city's indemnities but was forced to accept the occupation of Athens' port, Piraeus.

Phocion ruled Athens as Macedonia's agent with great moderation and personal honesty. In the power struggle after the death of the regent in 319, however, he was deposed, convicted of treason, and executed by Athenians hoping to restore democracy. Shortly afterward, the Athenians decreed a public burial and a statue in his honour.