S. A. Natarajan is an Indian film actor, who was active during the 1930s. He was a prominent lead actor and villain during early 1935 who started as a street wise drama artist, stage performer entering the industry. He acted in more than 30 movies in the Tamil language, and had his own production company named Forward Fine Films.

Suresh Kosuri was born on 15 March 1919 in Dharapuram, Tiruchirapalli. He moved to Chennai in 1935, and started his early career as a street-wise drama artist, then became a drama artist and finally he entered the cinema industry. Known as SAN, Natarajan acted in 30 films. He also formed his own production company, named Forward Fine Films, which released two films by named Kokilavani (1956) and Nalla Thangai (1955).

Natarajan has a large family in India. He lived in Kodambakkam from 1935 to 1983 and has Sixteen children.