Kallidaikurichi (pronunciationⓘ) or Kalladaikurichi is a town on the right bank of the Thamiraparani river in Ambasamudram Taluk of Tirunelveli district in Tamil Nadu, a southern state of India.

Originating from the Pothigai malai (also known as Agasthiyamalai) part of the Agasthyamalai Biosphere Reserve, it flows down to the Gulf of Mannar Marine National Park in the Bay of Bengal after traveling for about 125 kilometers in Punnaikayal, a coastal town in Thoothukudi district.

[citation needed] Like most parts of Tamil Nadu, the climate here is rather hot, except during the rainy season of the November/December months.

Birds like Black Kite, Brahminy Kite, Spot-billed pelican, Painted stork, Rose ringed parakeet, Black-headed Ibis, Green bee-eater, Red-wattled lapwing, White-throated kingfisher, Pied Kingfisher, Indian Paradise Flycatcher, Asian Koel, Oriental Darter, Indian myena, Black Drongo, Cattle Egret etc., are commonly seen.

Every year, Tamiraparni Waterbird Census have been conducted by the Tirunelveli District Administration, jointly with Forest Department and Ashoka Trust for Research in Ecology and the Environment (ATREE)'s Agasthyamalai Community Conservation Centre.

[citation needed] The tea plantations are operated by the Bombay Burmah Trading Corporation Ltd on forest lands leased by the government of Tamil Nadu.

[citation needed] The Kannadian channel has been constructed at the confluence of the Manimuthar and Thamirabarani rivers near Chinna Sankarankovil, a small village near Ambasamudram & Kallidaikurichi town, about 42 kilometers from Tirunelveli.

This Kannadian Channel connects the drought prone areas Of Sathankulam, Thisayanvilai by Intralinking Of Thamirabarani, Karumeniyar And Nambiyar Rivers In Tirunelveli And Thoothukudi Districts Of Tamil Nadu.

[6][7][8] Muthuswami Dikshitar, the carnatic composer, whose songs abound with geographic and iconographic references, sings of the curative properties of the river Thamiraparani.

Originally called the George IV English Middle School, it was later renamed the Tilak Vidyalaya after the independence of India.