Gumer is one of the woredas in the Southern Nations, Nationalities, and Peoples' Region of Ethiopia. This woreda is named after one of the sub-groups of the Sebat Bet Gurage, the Gumer. Part of the Gurage Zone, Gumer is bordered on the southeast by the Silt'e Zone, on the southwest by Geta, on the northwest by Cheha, and on the north by Ezha. Towns in Gumer include Arek'it and K'ebul. Geta and Alicho Werero woredas were separated from Gumer.
Bodies of water in this woreda include Lake Arek'it, after which the town was named. Landmarks include Mugo Mountain, which has two mosques built in the early 19th century on its summit, and is covered with dense forests of indigenous trees which include native species of fig, African olive, Afrocarpus gracilior, African juniper, and Cordia africana. The mountain also has strategic importance, having been used by the Italian army during the Italian occupation as a fortress. Mount Mugo is also the source of the Yo, Ayisechi and Balkech rivers. Gumer has 82 kilometers of all-weather roads and one kilometer of dry-weather roads, for an average road density of 231 kilometers per 1000 square kilometers.