Mounam Sammadham () is a 1990 Indian Tamil-language legal thriller film written by S. N. Swamy, directed by K. Madhu and produced by Kovai Chezhiyan. The film stars Mammootty (in his Tamil film debut) and Amala. It revolves around a lawyer representing a wrongfully convicted man.
The film was released on 15 June 1990, and went on to become a commercial and critical success.
The plot revolves around the wrongful conviction of Sundaram, a businessman, and the efforts taken by his lawyer Raja to find the truth.
Mounam Sammadham was the first Tamil film of Malayalam actor Mammootty. It took inspiration from his own film Sandhyakku Virinja Poovu.
The music was composed by Ilaiyaraaja. The song "Kalyaana Thaen Nilaa" is set in Darbari Kanada raga, while "Chik Chik Chaa" is a synth-pop number.
Lyrics for the dubbed Telugu version Lawyer The Great were written by Rajasri.
N. Krishnaswamy of The Indian Express praised the film for the cast performances (particularly Mammootty), Ilaiyaraaja's music, the cinematography and Shivaji's comedy. C. R. K. of Kalki, however, was less positive, saying the film was like an ordinary novel. The film was both a critical and commercial success.