Karaikudi is a Greater municipality in Sivagangai district in the Indian state of Tamil Nadu. It is the 21st largest urban agglomeration of Tamil Nadu based on 2011 census data. It is part of the area commonly referred to as "Chettinad" and has been declared a Municipality by the Government of Tamil Nadu, on account of the palatial houses built with limestone called karai veedu.

Karaikudi comes under the Karaikudi Assembly constituency, which elects a member to the Tamil Nadu Legislative Assembly once every five years, and it is a part of the Sivaganga Lok Sabha constituency, which elects its member of parliament (MP) once in five years. The town is administered by the Karaikudi municipality, which covers an area of 100 km2 (39 sq mi). As of 2011, The town had a population of 181,851 of which 90,799 were males and 91,052 were females in 2011. The municipality consists of Karaikudi, Kanadukathan, Kandanur, Kottaiyur, Pallathur, Puduvayal, and Sankarapuram (census town).

This city is famous for karaikudi kandangi sarees a special type of sarees which come from and are woven in this area.The geographical indication presents the government of India of this kandaangi sarees.