Bungo Province (豊後国 Bungo no kuni) was a province of Japan in eastern Kyūshū in the area of Ōita Prefecture. It was sometimes called Hōshū (豊州), with Buzen Province. Bungo bordered Buzen, Hyūga, Higo, Chikugo, and Chikuzen Provinces.
At the end of the 7th century, Toyo Province was split into Buzen (literally, "the front of Toyo") and Bungo ("the back of Toyo"). Until the Heian period, Bungo was read as Toyokuni no Michi no Shiri.
It is believed that the capital of Bungo was located in the Kokokufu (古国府), literally "old capital," section of the city of Ōita, but as of 2016 no archaeological evidence has been found.
The honor of the holiest Shinto shrine of Bungo Province (豊前一宮, Buzen ichinomiya) was given to Usa Shrine known as Usa Hachimangu or Usa Jingu in Usa district (today Usa, Ōita). Usa shrine had not only religious authority but also political influence to local governance, but their influence was reduced until the Sengoku period.
During the Sengoku period, in the middle of the 16th century, Bungo was a stronghold of the Ōtomo clan. The Ōuchi clan in the western Chūgoku Region was influenced to Buzen politics. In the middle of the period, both clans declined. After Toyotomi Hideyoshi also took the power in Kyūshū, 120 thousand koku of Buzen province was given to Kuroda Yoshitaka since 1587, who made Kokura, currently part of Kitakyushu, Fukuoka, his site and built the castle. Other parts of the province were divided into pieces and given to other daimyōs.