Kayalpatnam is an 18-ward municipality in the Thoothukudi district of the Indian state of Tamil Nadu. Kayalpatnam is a historic coastal municipality in the Thoothukudi district of Tamil Nadu, India. It is known for its centuries-old maritime trade history, Islamic heritage, Hindu temples (mandirs) and unique cultural identity. According to the 2011 census, it has a population of 40,588.