Sivanathan Shanmugavelan Ramamoorthy (aka) Nellai Siva, was a comedian and a supporting actor, who predominantly worked in Tamil cinema. His first film was Aan Paavam released in 1985. He has worked in popular movies like Attagasam, Mahaprabhu, Vetri Kodi Kattu, Kannum Kannum. His way of speaking in the movies is complete of Nellai slang, which shows him unique from other supporting actors.
He started his film career by acting alongside then-famous actor Nagesh. He acted in a Tamil television serial in Pandiyan Stores which aired on Vijay Television.