Ko.Si. Mani (13 September 1929 – 2 December 2016) was an Indian politician who was the minister for co-operation, statistics and ex-servicemen in the Tamil Nadu state of India between 2006 and 2011 Dravida Munnetra Kazhagam (DMK) regime. He was instrumental in developing kumbakonam fisheries market and darasuram vegetable market.