As of 2001 India census, Chandigarh had a population of 900,635, making for a density of about 7900 persons per square kilometre. Males constitute 56% of the population and females 44%. The sex ratio is 777 females for every 1,000 males – which is the lowest in the country. Chandigarh has an average literacy rate of 73%, higher than the national average of 59.5%; with male literacy of 76% and female literacy of 68%. About 12% of the population is under 6 years of age. The main religions in Chandigarh are Hinduism (78.6%), Sikhism (16.1%), Islam (3.9%), and Christianity (0.8%) . Punjabi and Hindi are the main languages spoken in Chandigarh, but English is also quite prevalent. A small number of people also speak Urdu. However, the most common language for informal communication, especially among the youth of the city is a combination of Hindi and English, commonly referred to as Hinglish.

A significant percentage of the population of Chandigarh consists of people who had moved here from the neighbouring states of Punjab, Haryana and Himachal Pradesh to fill up the large number of vacancies in various government departments that were established in Chandigarh.