Bungo-Ōno is a city located in Ōita Prefecture, Japan. As of 30 November 2023, the city had an estimated population of 32,846 in 15706 households, and a population density of 54 persons per km2. The total area of the city is 603.13 km2 (232.87 sq mi).

Ōita Prefecture is a prefecture of Japan located on the island of Kyūshū. Ōita Prefecture has a population of 1,136,245 and has a geographic area of 6,340 km2. Ōita Prefecture borders Fukuoka Prefecture to the northwest, Kumamoto Prefecture to the southwest, and Miyazaki Prefecture to the south.