The ethno-linguistic composition of the population of South Asia, that is the nations of India, Pakistan, Bangladesh, Nepal, Bhutan, Maldives and Sri Lanka is highly diverse. The majority of the population fall within two large Linguistic groups, Indo-Aryan and Dravidian. Indian society is traditionally divided into castes or clans, not ethnicities, and these categories have had no official status since Independence in 1947, except for the scheduled castes and tribes which remain registered for the purpose of Affirmative Action. In today's India, the population is categorized in terms of the 1,652 mother tongues spoken.

These groups are further subdivided into numerous sub-groups, castes and tribes. Indo-Aryans form the predominant ethno-linguistic group in Northern India, Bangladesh, Pakistan, Nepal, Sri Lanka and the Maldives. Dravidians form the predominant ethno-linguistic group in southern India and the northern and eastern regions of Sri Lanka, and a small pocket in Pakistan. Iranian peoples, grouped with Indo-Aryans in the Indo-Iranian language group, also have a significant presence in South Asia, the large majority of whom are located in Pakistan, with heavy concentrations in Balochistan, Khyber-Pakhtunkhwa and Federally Administered Tribal Areas. Dardic peoples form a minority among the Indo-Aryans. They are classified as belonging to the Indo-Aryan language group, though sometimes they are also classified as external to the Indo-Aryan branch. They speak an Iranic language which is not at all related to Indian languages. They are found in northern Pakistan (Northern Areas and Khyber-Pakhtunkhwa) and in Jammu and Kashmir, India.