Administrative Zone 1 was one of the three zones of the Ethiopian Region of Gambela. This zone was bordered on the south by Administrative Zone 2, on the west by Administrative Zone 3 and on the north and east by the Oromia Region. It was later added to Anuak Zone. Towns and cities in this zone included Itang and Gambela.
The terrain is mostly flat; rivers include the Baro, which is the only navigable river in Ethiopia, and the Alwero. A notable landmark is the Gambela National Park, which covers a large part of the Zone south of the Baro.