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.
Deder is a town in southeastern Ethiopia. Located in the East Hararghe Zone of the Oromia Region, with an altitude of above sea level. It is the administrative center of the Deder woreda (district).
Between 1954 and 1967 Deder received telephone service. Records at the Nordic Africa Institute website provide details of several schools in the town during the year 1968. By 1957 a Mennonite mission had been established in the town, which included a school and a hospital.
In the 1930s Deder was a center of coffee production, having a coffee market on the saddle between the Mounts Oubi and Mingna. The town was occupied by the Italians 21 July 1936.