338 BCCenturies: 5th century BC - 4th century BC - 3rd century BC
- August 2 - Battle of Cheronea: Philip of Macedon defeats Athens and Thebes in the definitive battle for Greek Independence
- King Arses of Persia ascends to the Persian throne.
- Agis III succeeds his father Archidamus III as king of Sparta
- Battle of Trifanum: The Roman general T. Manlius Torquatus decisively defeats the Latins.