Karthik Rathnam is an Indian actor who works in Telugu cinema and theater. He was born in 1996 or 1997 and made his debut in the 2018 film C/o Kancharapalem, which was the first Telugu film to be screened at the New York Film Festival. He has also appeared in Gods of Dharmapuri (G.O.D) on ZEE5 and the Tamil remake of C/o Kancharapalem. His other credits include Lingoccha, Changure Bangaru Raja, Rowdy Boys, and Sri Ranga Neethulu. 

Rathnam has also done many theater plays and playlets.