Nannawa Chiro is one of the Aanaas in Oromia Regional State, Ethiopia.

Part of the West Hararghe Zone, Chiro is bordered on the south by Kuni, on the west by Guba Koricha, on the northwest by Mieso, on the north by Doba, on the northeast by Tulo, and on the east by the Galetti River which separates it from Mesela and the East Hararghe Zone.

The highest peak in Chiro is Mount Arba Gugu (3574 meters).

[3] Based on figures published by the Central Statistical Agency in 2005, this woreda has an estimated total population of 412,938, of whom 201,965 are men and 210,973 are women; 37,296 or 9.03% of its population are urban dwellers, which is about the same as the Zone average of 9.6%.

With an estimated area of 1,786.88 square kilometers, Chiro has an estimated population density of 231.1 people per square kilometer, which is greater than the Zone average of 101.8.