Identity politics emerged as a scholarly inquiry in social science and humanities mainly in the second half of the twentieth century in the form of multiculturalism, women’s movement, Dalit and Adivasi movements, civil rights, lesbian and gay movements, separatist movements, and violent ethnic and nationalist movements in different parts of the world. The very claim of their movement emanates perhaps from the injustices done to them regarding their social position, vulnerability, marginalization, oppression by the so called cultural imperialism. However, it is in this context that the paper tries to analyze how identity politics developed in different scholarships particularly in social sciences and humanities and how different approaches define the process of identity formation. Along with this the paper examines identity politics in India in terms of caste, tribe, language, religion, region and ethnicity and explains how far and to what extent these identity markers pose a challenge to the unity and integrity of the nation.