Nagin (transl. Female Serpent) is a 1976 Hindi-language horror film, produced and directed by Rajkumar Kohli, under the Shankar Movies banner. It stars Reena Roy in the title role alongside an ensemble cast of Sunil Dutt, Feroz Khan, Jeetendra, Sanjay Khan, Rekha, Mumtaz, Vinod Mehra, Yogeeta Bali, Kabir Bedi and Anil Dhawan; its music was composed by Laxmikant Pyarelal. Despite being a fantasy type film, it was a blockbuster at the box office and the highest-grossing film of 1976. Following the success of the film, Reena Roy attained star status.

It was inspired by François Truffaut's 1968 French film The Bride Wore Black, which was based on Cornell Woolrich's 1940 novel of the same name. The film was later remade in Tamil as Neeya? (1979), with Sripriya playing Nagin.