The chronological history of Subarnapur district can be dated from 8th century AD, when it was known as Swarnapur and was a part of Khinjali Mandal, ruled by the Bhanjas as the feudatory of the Bhaumakaras of Toshali. The District was ruled by many dynasties from its past.
The Somovamsi ruler Janmajaya I (850–885) occupied this region from the Bhanjas and laid the foundation of Suvarnapur kingdom. Gradually the Somovamsi kingdom extended as far as Utkala and for the better administration of the newly conquered territory, the empire was divided into two parts by the ruler Yayati–II (AD 1023–1040) as Utkal Desa with Abhivava Yayati nagar (modern jajpur) as its capital, ruled by the king himself and Kosala Desa with its headquarter at Suvarnapur which remained in charge of a princely royal blood. In AD 1070, the Telgu–chodas as the feudatory of the Chindaka Nagas of Bustar region, occupied Suvarnapura from the than Somavamsi viceroy and ruled over this region for a period of 45 years. In AD 1113, the Kalachuris expelled the Telgu–Chodas and ruled over Suvarnapura for about 100 years.
In the meantime, the Somavamsis were ousted from the Utkala region by the imperial Gangas. This region was also occupied by the imperial Ganga monarch Anangabhimadeva–III (AD 1211–1238). They were later ousted by the Bhanjas, who first made Sonepur as their capital and later on shifted it to Boudh due to the expansionist policy of the Chouhan Rulers of Patna.
Meanwhile, the Chouhan rule was established in the Patnagarh (Bolangir District) region by Ramai Deo. Later on, a branch of this family established themselves in Sambalpur as its ruler. His successor, Balabhadradeva (AD 1605–1630) occupied Sonepur region from the Bhanja ruler of Boudh Siddhabhanja deva. The next Chouhan ruler of Sambalpur Madhukaradeva constituted the newly conquered territory into a vassal state and entrusted it to his second son Madan Gopal, who laid the foundation of the Chouhan kingdom of Sonepur on AD 1640. Since then the Chouhans ruled over Sonepur kingdom till its merger with the Orissa province on 1st January 1948 and became a Sub–Division under Bolangir District. However, from 1st April 1993, Sonepur was given the status of a District Headquarter.