The Oromia Region (Oromiyaa) is one of the nine regional states of Ethiopia, the homeland of the Oromo. It is bordered by the Somali Region to the east; the Amhara Region, the Afar Region and the Benishangul-Gumuz Region to the north; South Sudan, Gambela Region, and Southern Nations, Nationalities, and Peoples' Region to the west; and Kenya to the south. The 2011 census reported the population of Oromia as 35,000,000; this makes it the largest regional state in population.
Oromia includes the former Arsi Province along with portions of the former Bale, Hararghe, Illubabor, Kaffa, Shewa and Sidamo provinces. Towns in the region include Adama, Ambo, Asella, Badessa, Bale Robe, Bishoftu, Begi, Chiro, Dembidolo, Fiche, Gimbi, Goba, Haramaya, Jimma, Metu, Negele Borana, Moyale, Nekemte, Sebeta, Shashamane, and Waliso, among many others.
The current regional capital of Oromia is Addis Ababa, also known as Finfinne (which is also the capital of the country). It was changed from Addis Ababa to Adama in 2000, a move that sparked considerable controversy; the government was forced to bring the regional capital back to Addis Ababa on 10 June 2005. Critics of the move believed the Ethiopian government wished to de-emphasize Addis Abeba's geographic location as an enclave surrounded by Oromia. On the other hand, the government maintained that Addis Ababa "has been found inconvenient from the point of view of developing the language, culture and history of the Oromo people."
Oromia shares a boundary with almost every region of Ethiopia except for the Tigray Region. This boundary has been disputed with Oromia's neighbors in a number of cases, most notably between Oromia and the Somali Region. One attempt to resolve the dispute between the two regions was the October 2004 referendum held in about 420 kebeles in 12 woredas across five zones of the Somali Region. According to the official results of the referendum, about 80% of the disputed areas have fallen under Oromia administration, though there were allegations of voting irregularities in many of them. The results led over the following weeks to minorities in these kebeles being pressured to leave. In Oromiya, estimates based on figures given by local woreda and kebele authorities suggest that 21,520 people have been displaced in border woredas, namely Mieso, Doba, and Erer in the Mirab and Misraq Hararghe Zones. Federal authorities believe that this number may be overstated by as much as 11,000. In Doba, the Ministry of Federal Affairs put the number of IDPs at 6,000. There are also more than 2,500 displaced persons in Mieso. In addition, there were reports of people being displaced in the border area of Moyale and Borena zones due to this conflict.
On 12 September 2015 and continuing into 2016, protests broke out across Ethiopia and centered around the Oromia Region. Dozens of protesters were killed in the first days of the protests and internet service was cut in many parts of the region.
Ethiopian Airlines Flight 302 crashed in the woreda (district) of Gimbichu on 10 March 2019.