Mathai Chacko (12 May 1959 – 13 October 2006) was a politician from Kerala state. He was member of the Kerala Legislative Assembly from 2001 - 2006. He represented the Thiruvambadi constituency of Kerala and was a member of the Communist Party of India (Marxist) (CPI(M)) political party. He became the first elected MLA to take oath outside the Kerala Legislative Assembly, having taken oath at in Kochi, where he was undergoing treatment for leukemia, on 29 May 2006.