Nagapattinam Tamil: நாகப்பட்டினம் (nākappaṭṭinam) (previously spelt Nagapatnam or Negapatam) is a town in the Indian state of Tamil Nadu and the administrative headquarters of Nagapattinam District. It is a prominent seaport on the east coast of India and an important centre of trade and commerce.

The town of Nagapattinam dates back to the Sangam period. The Chudamani Vihara in Nagapattinam was constructed by the Medieval Cholas. Nagapattinam was settled by the Portuguese and later, the Dutch under whom it served as the capital of Dutch Coromandel from 1660 to 1781. In November 1781, Nagapattinam was conquered by the British East India Company. It served as the capital of Tanjore district from 1799 to 1845. In 1991, it became the capital of the newly-created Nagapattinam District. The town was severely damaged by the Indian Ocean Tsunami of 2004.

Sea-borne trade and fishing are the major sources of income for the town. There are also a number of pilgrimage sites and tourist destinations, notable amongst them being Sikkal Singaravelan Temple, Basilica of Our Lady of Good Health, the Nagore Dargah and Puhar.