S. Semmalai is an Indian politician active in Tamil Nadu.
He is the incumbent member of the state legislative assembly (MLA) from Mettur constituency.
He has been elected four times to the Tamil Nadu state assembly and once to the national parliament of India (2009–14).
Semmalai has won four elections in his career spanning from 1980 to the present.
This article about an All India Anna Dravida Munnetra Kazhagam politician is a stub.