Tamil–Kannada is an inner branch (Zvelebil 1990:56) of the Southern Dravidian I (SDr I) subfamily of the Dravidian languages that include Tamil, Kannada and Malayalam. (There have been slight differences in the way Dravidian languages are grouped by various Dravidian linguists: See Subrahmanyam 1983, Zvelebil 1990, Krishnamurthi 2003). Tamil–Kannada itself is designated as a branch of the South Dravidian subfamily and in turn branches off into Tamil–Malayalam and Kannada–Badaga. The languages that constitute the Tamil–Kannada branch are Tamil, Kannada, Malayalam, Irula, Toda, Kota, Kodava, and Badaga. (Zvelebil 1990:56)

According to R. C. Hiremath, the separation of Tamil and Kannada into independent languages from the Tamil–Kannada inner branch started with the separation of Tulu in about 1500 BCE and completed in about 300 BCE.

Kannada, Tamil and Malayalam are recognized among the official languages of India and are spoken mainly in South India. All three are officially recognized as classical languages by the Government of India, along with Sanskrit, Telugu, and Odia.