| C. K. Sadasivan | |
| Birth Date: | 17 February 1953 |
| Nationality: | Indian |
| Office: | Member of the Kerala Legislative Assembly |
| Constituency: | Kayamkulam |
| Predecessor1: | M. M. Hassan |
| Successor1: | U. Prathibha |
| Office2: | Member of the Kerala Legislative Assembly |
| Constituency2: | Ambalappuzha |
| Predecessor2: | V. Dinakaran |
| Successor2: | Suseela Gopalan |
| Party: | Communist Party of India (Marxist) |
C. K. Sadasivan (born 17 February 1953) is an Indian politician and former member of the Kerala Legislative Assembly. He belongs to the Communist Party of India (Marxist). He was elected to the Kerala Legislative Assembly in 1991, 1996 and 2006.[1]