As of the census of India 2001, Nellikuppam had a population of 44,222 comprising 22,179 males and 22,043 females, making the sex ratio (number of females per thousand males) of the town to 994. A total of 5,327 people were under six years of age and the child sex ratio (number of females per thousand males under six years of age) stood at 960. The town had an average literacy of 76.94%, higher than the national average of 59.5%. A total of 14,919 comprising 38.36% of the population belonged to Scheduled Castes (SC) and 48 comprising 0.12% of the population belonged to Scheduled tribes (ST). There were are total of 9,077 households in the town. As of 2001, Nellikuppam had a total of 11,014 main workers: 409 cultivators, 2,823 agricultural labourers, 165 in house hold industries and 7,617 other workers. There was a total of 3,224 marginal workers: 54 marginal cultivators, 1,939 marginal agricultural labourers, 80 marginal workers in household industries and 1,151 other marginal workers.