M K Muthu is an Indian actor, singer and politician.
Muthu is the first son of former Tamil Nadu chief minister M Karunanidhi.
Muthu first started acting in 1970, and appeared in films such as Pillaiyo Pillai, Samayalkaran, Anayavilaku, ‘Ingeyum Manidhargal’ and Pookari. He also sang a few numbers in his films. In 2008, he sang a song for the film Mattuthavani under music director Deva.