Tamil nationalism is the ideology which asserts that the Tamil people constitute a nation and promotes the cultural unity of Tamil people. Tamil nationalism is primarily a secular nationalism, that focus on language and homeland. It expresses itself in the form of linguistic purism, linguistic nationalism, Social equality and Tamil Renaissance.

Tanittamiḻ Iyakkam was a linguistic-purity movement in Tamil literature which attempts to avoid loanwords from Sanskrit/Prakrit, English, Urdu and other non-Dravidian languages. The movement began in the writings of Maraimalai Adigal, Paventhar Bharathidasan, Devaneya Pavanar, and Pavalareru Perunchitthiranaar, and was propagated in the Thenmozhi literary magazine founded by Pavalareru Perunchithiranar. V. G. Suryanarayana Sastri, a professor, was a 19th-century figure in the movement; in 1902 he demanded classical-language status for Tamil, which it received in 2004.