The Indian caste system describes the social stratification and social restrictions in the Indian subcontinent, in which social classes are defined by thousands of endogamous hereditary groups, often termed as jātis or castes. Within a jāti, there exist exogamous groups known as gotras, the lineage or clan of a person, although in a handful of sub-castes like Shakadvipi, endogamy within a gotra is permitted and alternative mechanisms of restricting endogamy are used (e.g. banning endogamy within a surname).

Although generally identified with Hinduism, the caste system was also observed among followers of other religions in the Indian subcontinent, including some groups of Muslims and Christians. The Indian Constitution has outlawed caste-based discrimination, in keeping with the socialist, secular, democratic principles that founded the nation. . Caste barriers have mostly broken down in large cities, though they persist in rural areas of the country. The caste system, in various forms, does continue to play a major role in Indian society and politics.