Manmadhan (titled onscreen as Maanmathaun) is a 2004 Indian Tamil-language romantic crime thriller film directed by A. J. Murugan in his debut. Silambarasan plays dual roles for the first time in his career while Jyothika plays the female lead, with Sindhu Tolani, Santhanam, Atul Kulkarni, and Goundamani playing supporting roles. The music was composed by Yuvan Shankar Raja.

Manmadhan opened theatrically on 12 November 2004, coinciding with Diwali. It was received favourably and had a blockbuster run at the box office for over 150 days at the time of its release. The film was remade in Kannada as Madana (2006).