Vriddhachalam, also known as Virudhachalam, is a municipality and taluk headquarters situated in the Cuddalore district of Tamil Nadu, India. The town's ancient name is identified as Thirumudhukundram.
According to the 2011 census, the town had a total population of 73,585, consisting of 37,066 males and 36,519 females. The population of children between the ages of 0 and 6 is recorded at 7,735, representing 10.51% of the total population.
A notable landmark in the heart of the town is the Virudhagiriswarar temple, which is dedicated to Lord Shiva.