The Magonids were a political dynasty of Ancient Carthage from 550 BCE to 340 BCE. The dynasty was first established under Mago I, under whom Carthage became pre-eminent among the Phoenician colonies in the western Mediterranean.^{[citation needed]} Under the Magonids, the Carthaginian Empire expanded to include Sardinia, Libya, and for almost a decade much of Sicily.

Leading experts on Carthage have been sceptical as to whether it is even possible to reconstruct the internal history of Carthage, and this needs to be borne in mind in relation to the Magonids. Mago and his successors probably ruled less like kings and more like tyrants or political strongmen. Diodorus, however, describes them as kings according to the law, which implies a legal procedure rather than a naked seizure of power. Similarly, Herodotus tells us that Hamilcar I was "king by valour," implying selection rather than hereditary succession.

In 480 BCE, after Hamilcar I's death, the king lost most of his power to an aristocratic Council of Elders. In 308 BCE, Hannonian Bomilcar attempted a coup d'état to restore the monarch to full power, but failed, so that Carthage became in name as well as in fact a republic.

With the arrival of Mago, Carthaginian foreign policy appears to have changed dramatically. If previously Carthage had tentatively colonized the island of Ibiza on its own, it now took the lead, establishing itself firmly as the dominant Phoenician military power in the western Mediterranean.

Mago was succeeded by his son Hasdrubal I. The next successor was Hamilcar I, the son of Hasdrubal's brother Hanno. Carthage, always trying to rid itself of its opponent, the Greeks, might even have entered into an alliance with the Persian Xerxes (the accounts are unsure) in order to defeat the joint foe. Herodotus tells that it was believed that the decisive battle of Himera between Carthaginian and Greek forces on Sicily took place on the very same day that the Greeks met with the Persians in the famous battle of Salamis in 480 BCE in Greece itself. But the Greeks were victorious in both battles and Hamilcar met his death at Himera.

After Hamilcar's death, the dynasty continued with Hamilcar's son Hanno II 'the Navigator' up to 440 BCE, under whom a large part of Carthage's African dominions were conquered and more of the Atlantic coast of Africa was explored and settled. Great advances were also made in African inland trade. Meanwhile, Carthage appeared to make an effort in keeping itself out of any new wars on Sicily.

This peace and newly acquired vast trading empire also helped rebuild the Carthaginian military forces. By 410 BCE Hannibal I (son of Gisco and grandson of Hamilcar) was the king of Carthage. He immediately set out on a new campaign in Sicily, which in 409 BCE ended in the utter destruction of the city of Selinus, ally of the powerful Greek city state of Syracuse. Hannibal achieved true notoriety with the sheer destruction he wrought and with the cruelty with which he slaughtered thousands of prisoners.

It was at the siege of the Greek city of Agrigentum that an epidemic swept through the Carthaginian camp which killed Hannibal. Hannibal's cousin Himilco II (son of Hanno the Navigator and grandson of Hamilcar) now assumed the reins of power of Carthage. He was only formally crowned king in 396 BCE, but this most likely means that a Carthaginian king could only be installed in the city of Carthage itself and so he had to wait to receive his title formally until he returned home from Sicily.