Amphipolis (modern Greek: Amfipoli), was an ancient city of Macedonia, on the east bank of the river Strymon, where it emerges from Lake Cercinitis, about 3 m. from the sea.

Originally a Thracian town, known as Ennea Odoi ("Nine Roads"), it was colonized by Athenians with other Greeks under Hagnon in 437 BC, previous attempts--in 497, 476 (Schol. Aesch. De fals. leg. 31) and 465--having been unsuccessful.

In 424 BC it surrendered to the Spartan Brasidas without resistance, owing to the gross negligence of the historian Thucydides, who was with the fleet at Thasos. In 422 BC Cleon led an unsuccessful expedition to recover it, in which both he and Brasidas were slain (see Battle of Amphipolis).

The importance of Amphipolis in ancient times was due to the fact that it commanded the bridge over the Strymon, and consequently the route from northern Greece to the Hellespont; it was important also as a depot for the gold and silver mines of the district, and for timber, which was largely used in shipbuilding. This importance is shown by the fact that, in the peace of Nicias (421 BC), its restoration to Athens is made the subject of a special provision, and that about 417, this provision not having been observed, at least one expedition was made by Nicias with a view to its recovery.

Philip of Macedon made a special point of occupying it (357), and under the early empire it became the headquarters of the Roman propraetor, though it was recognized as independent. Many inscriptions, coins, etc., have been found here, and traces of the ancient fortifications and of a Roman aqueduct are visible.