Thangamalai Ragasiyam is an adventure film released in 1957, produced by B.R. Panthulu under Padmini Pictures.
The film stars Sivaji Ganesan and T.R. Rajakumari alongside Jamuna.
The plot follows Prince Gajendran, who grows up as a ferocious caveman after being separated from his parents at a young age by their enemy. He meets Amutha, whose love tames him, and they embark on a quest to discover the secret of Thangamalai in order to rescue his parents.
The film was directed by P. Neelakantan, who left after directing a large portion of the film, and was released simultaneously in Kannada as Rathnagiri Rahasya.