Seru is one of the Aanaas in the Oromia of Ethiopia. It is named after the Aanaa capital, Seru. Part of the Arsi Zone, Seru is bordered on the south and east by the Shebelle River which separates it from the Bale Zone, on the west by the Wabe River which separates it from Robe, on the north by Aminya, and on the northeast by the West Hararghe Zone. Woreda of Bale Gasegar was separated form Seru.