Untouchability is a form of social institution that legitimises and enforces practices that are discriminatory, humiliating, exclusionary and exploitative against people belonging to certain social groups. Although comparable forms of discrimination are found all over the world, untouchability involving the caste system is largely unique to South Asia.

Dalit, also some of them previously known as untouchables, is the lowest stratum of the castes in the Indian subcontinent. Dalits were excluded from the fourfold varna of the caste hierarchy and were seen as forming a fifth varna, also known by the name of Panchama. Several scholars have drawn parallels between Dalits and the Burakumin of Japan, the Baekjeong of Korea and the peasant class of the medieval European feudal system.