Tiyo is one of the woredas in the Oromia Region of Ethiopia. Part of the Arsi Zone, Tiyo is bordered on the south by Munesa, on the west by Ziway Dugda, on the northeast by Hitosa, and on the southeast by Digeluna Tijo. The administrative center of the woreda and Zone is Asella; other towns in Tiyo include Gonde.
Mount Chilalo is the highest point in this woreda. Rivers include the Katar, Kulmsa, Gonde, Dosha and Walkesa. A survey of the land in this woreda shows that 40% is arable or cultivable (32% was planted with cereals), 23.1% pasture, 8.7% forest, and the remaining 28.2% is considered swampy, mountainous or otherwise unusable.
Industry in the woreda includes the Asella Malt factory, 55 small industries including 39 grain mills employing 240 people, as well as 2023 registered businesses of which 21.7% were wholesalers, 53% retailers, and 25.3% service providers. There were 15 Farmers Associations with 13,704 members and 9 Farmers Service Cooperatives with 426 members. Tiyo has 16 kilometers of dry-weather and 46.5 of all-weather road, for an average road density of 98 kilometers per 1000 square kilometers. About 53.7% of the total population has access to drinking water.
The 2007 national census reported a total population for this woreda of 86,761, of whom 43,463 were men and 43,298 were women; 6,525 or 7.52% of its population were urban dwellers. The majority of the inhabitants said they practised Ethiopian Orthodox Christianity, with 58.5% of the population reporting they observed this belief, while 40.24% of the population were Muslim, and 1.05% of the population were Protestant.