Sir Kumarapuram Seshadri Iyer (also spelled Aiyar) (1 June 1845 – 13 September 1901), was an Indian advocate who served as the 15th Dewan of Mysore from 1883 to 1901.

Other notable achievements include the construction of the Vanivilas Sagar dam across Vedavati river, the initiation of the Shivanasamudra hydroelectric project in 1899 (the first such major attempt in India), electricity and drinking water (the latter through pipes) being supplied to Bangalore and the founding of the Archaeological Survey of Mysore (1890) and the Oriental Manuscripts Library.

Seshadri Iyer established the Kolar gold fields and Victoria Hospital and commissioned the Shivanasamudra hydel-electric power project.

His great-grandfather Gowri Seshan Pattu had migrated to Kumarapuram from Ganapathi Agraharam in Tanjore district at the turn of the 19th century.

Seshadri Iyer was educated in private until his eleventh year when he was admitted to the Free Church Mission School in Cochin.

Seshadri Iyer extended the railway lines in the kingdom by 270 kilometres (170 mi)The Kolar gold fields of Karnataka were established during his tenure.

Seshadri Iyer was responsible for initiating the first hydro-electric project in Asia, at Shivanasamudra, which began generating power in 1902 for the Kolar gold fields, and in 1905 for Bangalore.

The Mysore government, in consultation with the British Raj, decided to depopulate and demolish this area to prevent recurrence of plague and other infectious diseases which were common in those days.

Iyer's administration developed the extensions of Basavanagudi and Malleswaram from 1898 onwards in order to house the displaced population.

Not only did the extensions alleviate the congestion of the city, but also, many new industrial units came to be established in the vicinity, and people got more employment opportunities.

During the plague, Iyer also observed the need for a large and well-equipped hospital which would provide treatment in the European style of medicine.

K. S. Krishna Iyer also served in the Mysore State Service rising to the post of Deputy Commissioner.