Antimachus, of Colophon or Claros, Greek poet and grammarian, flourished about 400 BC.
Scarcely anything is known of his life. His poetical efforts were not generally appreciated, although he received encouragement from his younger contemporary Plato (Plutarch, Lysander, 18).
His chief works were: an epic Thebais, an account of the expedition of the Seven against Thebes and the war of the Epigoni; and an elegiac poem Lyde, so called from the poet's mistress, for whose death he endeavoured to find consolation telling stories from mythology of heroic disasters (Plutarch, Consul, ad Apoll. 9; Athenaeus xiii. 597).
Antimachus was the founder of "learned" epic poetry, and the forerunner of the Alexandrian school, whose critics allotted him the next place to Homer. He also prepared a critical recension of the Homeric poems.