Subarnapur District, also called Sonepur District or Sonapur District, is an administrative district of Odisha state in eastern India. The town of Sonepur is the district headquarters. Many loosely call the people of Sonepur region as Sonepuria.

According to historians the Subarnapur district was known as Paschima Lanka or Western Lanka around the 10th-11th centuries.The evidence comes from a copper plate charter issued in the late 10th century by a Somavansi prince named Kumara Someswaradeva of Subarnapur district.The Prince had identified himself as the king of Paschima Lanka. It was further found that the Mahada copper plate grant of Kumara Someswaradeva was registered on the bank of river Chitrotpala (Mahanadi) and near to the province of Lanka. The presiding deity of Paschima Lanka was goddess Lankeswari.

In 2006 the Ministry of Panchayati Raj named Subarnapur one of the country’s 250 most backward districts (out of a total of 640).It is one of the 19 districts in Odisha currently receiving funds from the Backward Regions Grant Fund Programme (BRGF).

According to the 2011 census Subarnapur district has a population of 652,107, roughly equal to the nation of Montenegro or the US state of Vermont.This gives it a ranking of 512th in India (out of a total of 640).The district has a population density of 279 inhabitants per square kilometre (720/sq mi).Its population growth rate over the decade 2001-2011 was 20.35%.Subarnapur has a sex ratio of 959 females for every 1000 males, and a literacy rate of 74.42%.

Subarnapur District is known for its influentially rich cultural heritage, arts and crafts. For instance, textiles and terracotta of Sonepur, Brass metal works and Philigri crafts of Tarbha and Binka, Stone carving of Ullunda and Paddy crafts of Dunguripali are recognized all over the state and also in country. In addition, the great poet and prophet of Mahima Dharma, Santh Bhima Bhoi was from this district. Besides, Subarnapur area is famous for ‘Danda-nata’, a religious folk tradition generally performed in the month of Chaitra.Historically Sonepur region was known as Paschima Lanka.