He is the son of veteran Actor of Tamil cinema, R. Muthuraman and his mother’s name is Sulochana. He did his schooling from the well-known; St. Bede's School in Chennai and finished his graduation in Arts from New College, Chennai.
Karthik Muthuraman started his acting career with the Tamil film Alaigal Oivathillai in 1981. Since then he was worked under almost all the prolific Directors of Southern film industry like Maniratnam, Balachandar, Fazil, Agathiyan, Vikraman, Sundar.C and P. Vasu and thereby established himself as a sought out Actor.
His pairing with Rambha was very famous during the 1990s and the pair has given several hits like Ninaivellam, Kelviyum, Naane, Agaya Gangai, Pakathu Veettu Roja, Nalla Thambi and Abhinandana amongst others.
Along with an accomplished actor, he is a distinguished Politician as well. He started his political career in 2006 by becoming the Secretary of the Tamil Nadu State unit of All India Forward Bloc. Three years later in 2009, he started his own political front, Ahila India Naadalum Makkal Katchi.
He married former Actress Ragini, his co-star in film Solai Kuyil with whom he has two sons Ghayn Karthik and Gautam Karthik. He married for the second time with Ragini’s sister Rathi in 1992 and with whom he has a son Thiran Karthik.