Chetti Thanabalasingam was a Sri Lankan criminal, most importantly known for his association with the leader of Liberation Tigers of Tamil Eelam (LTTE), Velupillai Prabhakaran, in the early days of insurgency. Thanabalasingam was the leader of Tamil New Tigers (TNT), the forerunner to the LTTE, which he and Prabhakaran formed in 1972. Prabhakaran served as its deputy. Thanabalasingam was a most wanted criminal by the Sri Lanka Police in connection with several crimes. Prabhakaran was a student of Thanabalasingam, and he had initially learnt the art of fighting and shooting from him. Chetti Thanabalasingam had served a prison term in Anuradhapura prison with S. Sabalingam, Kannady Pathan and Rathnakumar. They made their escape in a jail break. Later, Prabhakaran accused him that he cheated robbed money of Prabhakaran. After Thanabalasingam's death, Prabhakaran took over the TNT.
- Wilson Gnanadass (February 2009). "What next after LTTE’s defeat?". The Nation. Retrieved 2011-07-30.
- Taraki Sivaram (May 1994). "The Exclusive Right to Write Eelam History". Sunday Island. Retrieved 2011-07-30.
- T. Sabaratnam (December 2003). "The Split of the LTTE". Sangam.org. Retrieved 2011-07-30.