Ada'a is one of the woredas in the Oromia Region of Ethiopia. It is part of the former Ada'a Chukala woreda what was divided between Ada'a and Liben woredas. Part of the East Shewa Zone located in the Great Rift Valley, Ada'a is bordered on the south by Dugda Bora, on the west by the West Shewa Zone, on the northwest by Akaki, on the northeast by Gimbichu, and on the east by Lome.
Altitudes in this woreda range from 1500 to over 2000 meters above sea level. Although the highest point in Ada'a, and in Misraq Shewa, is Mount Yerer which lies on the border with Akaki, Mount Zuqualla is also a prominent peak as well as a notable landmark, as the monastery of Saint Gebre Manfas Qeddus is located on it. Rivers include the Modjo, Belbela, Wedecha and Dukem. Other bodies of water include the five crater lakes around Debre Zeyit: Lake Bishoftu, Lake Hora, Lake Bishoftu Guda, Lake Koriftu and the seasonal Lake Cheleklaka. Important forests include the government-protected Dirre-Garbicha and the Tedecha and Oude community forests. A survey of the land in this woreda shows that 51% is arable or cultivable, 6.4% pasture, 7.4% in community, regional and natural forests, and the remaining 34.8% is considered degraded or otherwise unusable. Legumes and sugar cane are important cash crops; Ada'a produces the most teff, wheat and legumes in Misraq Shewa.