The ʿAdhaim (العظيم) is a river that originates in the Zagros Mountains in Sulaymaniyah Governorate and joins the Tigris river after 230 kilometres (140 mi) at 34°00′07″N 44°17′35″E / 34.002°N 44.293°E, some 30 kilometres (19 mi) downstream (east-to-southeast) of Samarra.
Its basin extends to 12,965 square kilometres (5,006 sq mi). The river is fed by rainwater and peak discharge is between January and March.
Coordinates: 34°16′00″N 44°31′00″E / 34.2667°N 44.5167°E