Periyar Dasan was an eminent speaker and activist from Tamil Nadu. He was a Tamil Scholar and thinker. He propagated Atheism and Rationalist ideologies for most part of his life. He has also appeared in Tamil-language films. He had acted in around 15 films, starting with Karuthamma.

Born in a shaivite family he was attracted towards the rationalist ideals of Periyar E. V. Ramasamy founder of the Dravidian movement. During his days in Pachaiyappa’s college, he changed his original name Seshachalam to Periyar Dasan ('Ardent follower of Periyar'). He well versed in Tamil literature, various religious studies and English and he has authored around 120 books. He was served as a professor in his alma mater, Pachaiyappa’s college, for 34 years.