Poornam Viswanathan (15 November 1921 – 1 October 2008) was an Indian actor who predominantly appeared in Tamil films. He started performing on stage at age 18. He worked as a reader for All India Radio and went on to act in films such as Chithram, Varusham 16, Thillu Mullu, Keladi Kanmani, Moondram Pirai, Aasai, Mahanadi and Varumaiyin Niram Sivappu. He had a son and two daughters. Viswanathan died on 1 October 2008.