Nagapattinam district is a coastal district of Tamil Nadu state in southern India. Nagapattinam district was carved out by bifurcating the Erstwhile composite Thanjavur district on October 19, 1991. The town of Nagapattinam is the district headquarters. As of 2011, the district had a population of 1,616,450 with a sex-ratio of 1,025 females for every 1,000 males. It is the only discontiguous district in Tamil Nadu.