Sandur is a town in Bellary district of Karnataka state, India. It is the administrative seat of Sandur taluk.

Sandur Taluk has deposits of manganese ore and hematite (iron ore), and is home to several mines, including Donimalai Mine, an iron mine owned by the National Mineral Development Corporation , Subbarayanahalli Mine, an iron ore in Nandi Halli owned by Mysore Minerals Limited , Dharmapur Iron Ore Mines in Ramgad village, and Jaisingpur Iron Ore Mine in Yeshwanthanagar.

Before India's independence, Sandur was the seat of a princely state of the same name. The state was founded around 1700 by Shrimant Sidalji Ghorpade (died 1715), a Maratha Jagir. His successors ruled as rajas. In the eighteenth century, the surrounding territory came under the control of the Nizam of Hyderabad. In 1801 Bellary district was transferred to British India, and the rajas of Sandur came under the political authority of Madras Presidency. Area, 433 sq. km. (161 sq. mi.), Pop. (1901), 11,200; estimated revenue, 3 500. The military sanatorium of Ramandrug was located in the range of hills on the western border of the district.

The Raja of Sandur acceded to India on April 1 1949, and Sandur state was incorporated into Bellary district, then part of Madras state. In 1953 Bellary district was transferred to Mysore state, which was later renamed Karnataka.