Nagapattinam comes under the Nagapattinam assembly constituency and it elects a member to the Tamil Nadu Legislative Assembly every five years. From the 1977 elections, the assembly seat was won by Dravida Munnetra Kazhagam (DMK) once during the 1996 elections, All India Anna Dravida Munnetra Kazhagam (AIADMK) twice during the 1991 and 2001 elections, and Communist Party of India (Marxist) five times during the 1977, 1980, 1984, 1989 and 2006 elections. The current MLA of the constituency is K. A. Jayapal, the minister for fisheries in the Government of Tamil Nadu.