Kaštiliašu III, inscribed phonetically in cuneiform as mKaš-til-ia-šu, is a possible Kassite king of Babylonia in the 15th century BC (Short Chronology).
He may be the person indicated on line 21’[nb 1] of the Synchronistic King List[i 1][1] where he is placed opposite Assyrian king Aššur-nārāri I and is preceded by a lacuna and superseded by a poorly preserved name which is not thought to be Ulam-Buriaš.
He has no royal title in those, a feature of this chronicle that is shared by others, such as Samsu-Ditana, who, despite absent monarchical epithets, did prove to be kings.
[1] A recently published copy of a monumental inscription[i 2] celebrates his excavation of the Sumundar Canal and confirms his genealogy, son of Burnaburiaš I,[nb 2] grandson of Agum II.
It describes his ritual use of a silver spade and basket, which were subsequently displayed in the temple of Enlil, and his conscription of the people and land of Yamutbal for its excavation.