Diadochoupolis (el|Διαδοχούπολις, "city of the Diadochi") was a city in ancient Mesopotamia. The only source referring to it is a short mention by Stephanus Byzantius, who records that it was "οὺ πόρρω Κτησιφῶντος" ("not far from Ctesiphon").[1] It was located probably in the region of Sittacene in Mesopotamia on the bank of the river Tornadottos. Its inhabitants were known as Diadochenoi.