Decha is one of the woredas in the Southern Nations, Nationalities, and Peoples' Region of Ethiopia. The name Decha comes from one of the provinces in the former Kingdom of Kaffa, which had the approximately same boundaries. Part of the Keffa Zone, Decha is bordered on the south by the Omo River which separates it from the Debub Omo Zone, on the west by the Bench Maji Zone, on the northwest by Chena, on the north by Ginbo, on the northeast by Menjiwo, on the west by Telo and Cheta, and on the southeast by the Denchya River which separates it from the Konta special woreda. The major town in Decha is Chiri.
According to a 2004 report, Decha had 47 kilometers of all-weather roads and 5 kilometers of dry-weather roads, for an average road density of 18 kilometers per 1000 square kilometers. The southern tip of Decha is included in the territory of the Omo National Park.