Idu, also Idum (Sātu Qalā) was an ancient Near Eastern town in the Erbil Governorate in the Kurdistan region of Iraq, on the right bank of the Lower Zab.

The site was definitively occupied in the Late Bronze age Middle Assyrian period, in the later half of the 2nd millennium BC, based on an inscribed brick, an excavated palace, and a cylinder seal, when it was the capital of Idu province.

After the fall of the Middle Assyrian Empire the city became independent for several centuries, with known rules named Abbizeri, Bal’ilanu and Eristenu, and Baiuri.

Finds included 41 inscribed objects in the Assyrian dialect of Akkadian, none in situ and most were bricks originating in an embankment wall of the palace.

All of the inscribed bricks were of local rulers except for one Neo-Assyrian fragment "Palace of Aššurnaṣirpal, king of the land of Aššur …".