The Battle of Crocus Field () (also known as the "Battle of Volo") was a battle in the Third Sacred War, fought between the armies of Phocis, under Onomarchos, and the combined Thessalian and Macedonian army under Philip II of Macedon. In the bloodiest battle recorded in Ancient Greek history, the Phocians were decisively defeated by Philip's forces. Philip's victory secured his appointment as ruler of Thessaly, marking an important step in the rise of Macedon to political ascendancy in Ancient Greece. Opinion amongst historians is divided as to the year of the battle; some favour 353 BC, and others 352 BC.