Kalyana Rathriyil () is a 1966 Indian Malayalam-language crime thriller film directed by M. Krishnan Nair and produced by M. Raju Mathan. The film stars Prem Nazir, Adoor Bhasi, Muthukulam Raghavan Pillai and T. S. Muthaiah. Notably, it is the first Malayalam film to receive an A (adults only) certificate. The horror in the film stems from its suspenseful plot, which involves a man investigating his in-laws' connection to a ghost on his wedding night.
The story follows a man named Rajan who becomes suspicious of his new in-laws and a ghost linked to them, leading him to investigate the mystery during his wedding night.
The music was composed by G. Devarajan and the lyrics were written by Vayalar Ramavarma.