Apil-Sin was an Amorite King of the First Dynasty of Babylon (the Amorite Dynasty). He possibly reigned between c. 1767 to 1749 BC.^[1]

Apil-Sin was the grandfather of Hammurabi, who significantly expanded the Babylonian kingdom. Little is known of the details of Apil-Sin or his reign as king of Babylon; in fact, there are no surviving references to his claiming to be king of the city state. The absence of records is often used by scholars as evidence that at this time Babylon was still a new and minor city-state, and that Apil-Sin's power and influence were much smaller than that of his grandson, Hammurabi.

It is a noteworthy fact that in the large numbers of business documents that have come down to us out of this first dynasty of Babylon, none of the rulers down to Apil-Sin is called king and Sin-Muballit only in the form of a passing allusion in one single tablet. It is difficult to explain this fact unless we accept the view that the real kingdom of Babylon did not begin until Hammurabi had driven out the Elamites and so won for himself the title borne by the old kings of Ur, Isin, and Larsa.

— A History of Babylonia and Assyria, Volume I^[2]

• Babylonia