Nenjil Oru Mull () is a 1981 Indian Tamil-language film written and directed by Mathi Oli Shanmugam. A remake of the Hindi film Kati Patang (1971), which in turn was based on the 1948 novel I Married a Dead Man by Cornell Woolrich, it stars Poornima Jayaraman and Pratap. The film was released on 11 December 1981.
Nenjil Oru Mull is the first Tamil film for Poornima Bhagyaraj (née Jayaraman). The film is a remake of the Hindi film Kati Patang (1971), which in turn was based on the 1948 novel I Married a Dead Man by Cornell Woolrich. It was predominantly filmed in Coimbatore. One shot required Poornima to run on an overpass. Cinematography was handled by Ashok Gunjal, and editing by R. Devarajan.
The soundtrack was composed by G. K. Venkatesh. This is the debut film for lyricist Ponnadiyan.
Nenjil Oru Mul was released on 11 December 1981, and failed commercially.