An Indian screenplay writer, M. Rathnam has predominantly worked in Tamil film industry. He made his debut with the 1994 film Bobbili Simham, followed by Samarasimha Reddy (1999) and Simhadri (2003). He has also written dialogues for films like Sye (2004), Vikramarkudu (2006), Raju Bhai (2007), and Magadheera (2009). He has penned down the story for films Legend (2014) and Dictator (2016). His other projects include Jai Simha (2018), Vinaya Vidheya Rama (2019) and Akhanda (2021).