One of the 38 districts in the southern Indian state of Tamil Nadu is Nagapattinam district. The former composite Thanjavur district was divided into two districts on October 19, 1991, creating the district of Nagapattinam. The district headquarters is located in the town of Nagapattinam.

In Tamil Nadu, Nagapattinam was the only discontiguous district until Mayiladuthurai district was formed out of it on March 24, 2020.