Deder is one of the woredas in the Oromia Region of Ethiopia. It is named after the administrative center, Deder. Part of the Misraq (East) Hararghe Zone, Deder is bordered on the south by Malka Balo, on the west by the Mirab (West) Hararghe Zone, on the north by Goro Gutu, on the east by Meta, and on the southeast by Bedeno. Towns in the woreda include Kobo.
The altitude of this woreda ranges from 1200 to 3140 meters above sea level; Gondela is the highest point. Rivers include the Gelan Sedi. A survey of the land in this woreda (released in 1995) shows that 32.5% is arable or cultivable, 2.6% pasture, 1.7% forest, and the remaining 63.2% is considered degraded, built-up or otherwise unusable. Khat, fruits, and vegetables are important cash crops.Coffee is also an important cash crop; over 50 square kilometers are planted with it.
Industry in the woreda includes 25 grain mills and 2 wood-working factories employing 29 people, as well as 381 registered businesses including wholesalers, retailers and service providers. Graphite, marble, copper, iron, lead and nickel deposits are known to exist, but none have been developed. There were 33 Farmers Associations with 36,073 members and 4 Farmers Service Cooperatives with 4078 members. Deder has 84 kilometers of dry-weather, 68 kilometers of asphalt-surfaced and 83 of all-weather road, for an average road density of 507.6 kilometers per 1000 square kilometers. About 16.4% of the urban and 7.4% of the rural population have access to drinking water.