Delhi is a metropolitan region in India that includes the national capital city, New Delhi. With a population of 22 million in 2011, it is the world's second most populous city and the largest city in India in terms of area.The NCT and its urban region have been given the special status of National Capital Region (NCR) under the Constitution of India's 69th amendment act of 1991. The NCR includes the neighbouring cities of Baghpat, Gurgaon, Sonepat, Faridabad, Ghaziabad, Noida, Greater Noida and other nearby towns, and has nearly 22.2 million residents.

According to the 2011 census of India, the population of Delhi is 16,753,235. The corresponding population density was 11,297 persons per km2, with a sex ratio of 866 women per 1000 men, and a literacy rate of 86.34%. In 2004, the birth rate, death rate and infant mortality rate per 1000 population were 20.03, 5.59 and 13.08, respectively. In 2001, the population of Delhi increased by 285,000 as a result of migration and by 215,000 as a result of natural population growth - this made Delhi one of the fastest growing cities in the world. By 2015, Delhi is expected to be the third-largest conurbation in the world after Tokyo and Mumbai. Dwarka Sub City, Asia's largest planned residential area, is located within the National Capital Territory of Delhi.