Indian nationality law details the conditions by which a person holds Indian nationality. The two primary pieces of legislation governing these requirements are the Constitution of India and the Citizenship Act, 1955.

All persons born in India between 26 January 1950 and 1 July 1987 automatically received citizenship by birth regardless of the nationalities of their parents. Between 1 July 1987 and 3 December 2004, citizenship by birth was granted if at least one parent was a citizen. Individuals born in the country since then receive Indian citizenship at birth only if both parents are Indian citizens, or if one parent is a citizen and the other is not considered an illegal migrant.

Foreigners may become Indian citizens by naturalisation after residing in the country for at least 12 years and renouncing any previous nationalities. Members of certain religious minority communities from neighbouring countries qualify for a reduced residence requirement of six years. Indian citizens who permanently settle in Pakistan or Bangladesh, or voluntarily acquire foreign citizenship automatically lose Indian citizenship.

India was previously ruled by the British Empire and local residents were British subjects and British protected persons. Although India gained independence in 1947 and Indians no longer hold British nationality, they continue to have favoured status when residing in the United Kingdom; as Commonwealth citizens, Indians are eligible to vote in UK elections and serve in public office there.