Kahaani (IPA: [kəˈɦaːni]; transl. Story) is a 2012 Indian Hindi-language thriller film co-written, co-produced, and directed by Sujoy Ghosh. It stars Vidya Balan as Vidya Bagchi, a pregnant woman looking for her missing husband in Kolkata during the festival of Durga Puja, assisted by Assist Sub-Inspector Satyoki "Rana" Sinha (Parambrata Chatterjee) and Inspector General A. Khan (Nawazuddin Siddiqui).

Made on a shoestring budget of ₹80 million (US$920,000), Kahaani was conceived and developed by Ghosh, who co-wrote the film with Advaita Kala. The crew often employed guerrilla-filmmaking techniques on Kolkata's city streets to avoid attracting attention. Its creative portrayal of the city and its use of local crew and cast members made it a notable film. Kahaani explores themes of feminism and motherhood in a male-dominated Indian society. The film also makes several allusions to Satyajit Ray's films, such as Charulata (1964), Aranyer Din Ratri (1970), and Joi Baba Felunath (1979). The film's musical score and soundtrack are composed by Clinton Cerejo and Vishal–Shekhar respectively, with cinematography handled by Setu and editing done by Namrata Rao.

Kahaani was released worldwide on 9 March 2012. Critics praised the screenplay, the cinematography and the performances of the lead actors. Following critical acclaim and word-of-mouth publicity, the film earned ₹1.04 billion (US$12 million) worldwide in 50 days. The film won several awards, including three National Film Awards and five Filmfare Awards. The latter included trophies for Best Director (Ghosh) and Best Actress (Vidya). The film was remade by Sekhar Kammula in Telugu as Anaamika (2014) with Nayanthara reprising Vidya's role. A spiritual successor, titled Kahaani 2: Durga Rani Singh, was released on 2 December 2016.