Apoorva Raagangal (pronounced [apuːɾʋa ɾaːɡaŋɡaɭ] transl. Rare melodies) is a 1975 Indian Tamil-language romantic drama film written and directed by K. Balachander. It stars Kamal Haasan, Sundarrajan, Srividya and Jayasudha, while Nagesh and Rajinikanth, in his feature film debut, play supporting roles. The film revolves around Prasanna (Haasan) who falls in love with the much older Bhairavi (Srividya) while Bhairavi's daughter Ranjani (Jayasudha) is drawn to Prasanna's father Mahendran (Sundarrajan).

Apoorva Raagangal's theme was based on a riddle featured in the Indian folktale collection Vetala Panchavimshati about a king marrying a woman and his son marrying her mother, and Vetala, the riddler asking Vikramaditya what would be their kinship relations if these couples were to beget children. The film was produced by V. Govindarajan and J. Duraisamy under the Kalakendra Films banner, photographed by B. S. Lokanath and edited by N. R. Kittu; the music is composed by M. S. Viswanathan. Unlike many contemporaneous Tamil films, it was shot entirely in actual houses for their interiors without building sets, as Balachander wanted to convey a more authentic narration.

Apoorva Raagangal was released on 15 August 1975. Despite exploring the concept of relationships between people with wide age gaps, which challenged Indian social mores, it received critical acclaim and became a commercial success, and a breakthrough for Srividya and Haasan. The film won three National Film Awards, including Best Feature Film in Tamil, and three Filmfare Awards South in the Tamil branch: Best Feature Film, Best Director for Balachander and Best Actor for Haasan, and a Special Award for Srividya. It was remade in Telugu as Thoorpu Padamara (1976) where Srividya and Nagesh reprised their roles, and in Hindi by Balachander as Ek Nai Paheli (1984) where Haasan reprised his role.