K. D. Santhanam was an Indian stage and film actor, script writer and film lyricist who worked mainly in Tamil films.
He was a teacher at Madurai Sri Mangala Bala Gana Sabha training young boys in dramatics. He was known as a strict disciplinarian. He punished erring boys beating them with a cane, sometimes chasing the running boys. One of his students became a renowned actor later who acknowledged to his friends that it was due to the discipline of his tutor he was able to reach heights. The actor is Sivaji Ganesan. Later Santhanam has done minor character roles in which Sivaji Ganesan featured as the hero. This information has been recorded by writer Aroordas in his biography.
He is a character artiste and has featured in more than 100 films.
In Pasamalar he featured as Rajaratnam, a village senior who arranges the marriage of Sivaji Ganesan with M. N. Rajam.
Ahaa Enna Porutham is a hit song from the film Ragasiya Police 115. In between the verses one can hear a commanding voice asking "Ange ennamma saththam?" (What is the noice there?). The voice is of Santhanam who featured as Dhanapal Muthaliar (a filmmaker), father of Neela (Jayalalitha) in the film.
He featured as the father of M. G. Ramachandran in the film Aasai Mugam.
During the 1950s, Tamil Cinema had a number of classic lyricists who enriched the films with their variety of songs. Udumalai Narayana Kavi and Pattukkottai Kalyanasundaram wrote leftist oriented songs. A. Maruthakasi specialised in Agricultural songs. Ku. Ma. Balasubramaniam wrote melodious songs. Kannadasan wrote on life and philosophy. Thanjai N. Ramaiah Dass wrote songs that appealed to the common man. Santhanam made his mark by writing songs with rhythmic flow known in Tamil as Santham.