Metapontum or Metapontium (Ancient Greek: Μεταπόντιον, romanized: Metapontion) was an important city of Magna Graecia, situated on the gulf of Tarentum, between the river Bradanus and the Casuentus (modern Basento).

Justin, conversely, tells us it was founded by Epeius; in proof of which the inhabitants showed, in a temple of Minerva, the tools which the hero had used to build the Trojan Horse.

It is known that at the time of the foundation of this city the site was unoccupied; the Achaean settlers at Crotona and Sybaris were therefore desirous to colonize it, in order to prevent the Tarentines from taking possession of it.

Another and a more plausible statement is that the new colonists were at first engaged in a contest with the Tarentines, as well as the neighbouring tribes of the Oenotrians, which was at length terminated by a treaty, leaving them in the peaceable possession of the territory they had acquired.

It does not appear that Metapontum took any part in the war between Crotona and Sybaris, which ended in the destruction of the latter city; but its name is frequently mentioned in connection with the changes introduced by Pythagoras, and the troubles consequent upon them.

The Metapontines paid the greatest respect to his memory; they consecrated the house in which he had lived as a temple to Ceres, and gave to the street in which it was situated the name of the Museum.

[11] At the time of the Athenian expedition to Sicily, 415 BCE, the Metapontines at first, like the other states of Magna Graecia, endeavoured to maintain a strict neutrality; but in the following year were induced to enter into an alliance with Athens, and furnish a small auxiliary force to the armament under Demosthenes and Eurymedon.

[13] In 332 BCE, when Alexander, king of Epirus, crossed over into Italy at the invitation of the Tarentines, the Metapontines were among the first to conclude an alliance with that monarch, and support him in his wars against the Lucanians and Bruttians.

[15] It is evident that Metapontum was at this period still wealthy; but its citizens had apparently, like their neighbors the Tarentines, fallen into a state of slothfulness and luxury, so that they were become almost proverbial for their lack of vigor.

They were among the first to declare in favor of Hannibal after the battle of Cannae;[17] but notwithstanding this, their city was occupied by a Roman garrison some years later, and it was not until after the capture of Tarentum, in 212 BCE, that they were able to rid themselves of this force and openly espouse the Carthaginian cause.

But it did not altogether cease to exist; for its name is found in Pomponius Mela[20] who does not notice any extinct places; and Cicero speaks of visiting it in terms that show it was still a town.

Though Metapontum is mentioned less than of Sybaris, Crotona, and Tarentum, yet all accounts agree in representing it as, in the days of its prosperity, one of the most opulent and flourishing of the cities of Magna Graecia.

The Torre di Mare, now the only inhabited spot on the plain, derives its name from a castellated edifice of the Middle Ages; it is situated 2.5 km from the sea, and the same distance from the river Basiento, the ancient Casuentus.

Immediately opposite to it, on the sea-shore, is a small salt-water basin or lagoon, now called the Lago di Santa Pelagina, which, though neither deep nor spacious, in all probability formed the ancient port of Metapontum.