As of 2001 India census, Mangalore had a population of 398,745. As of the same census, the urban area had a population of 538,560. According to World Gazetteer, Mangalore’s population in 2008 was 431,976, making it the 101th most populous city in India. As of the same census, the World Gazetteer estimated the population of the Mangalore urban area to be 603,269, making it the 61th most populated metropolitan area in India. Males constitute 50% of the population and females 50%. Mangalore has an average literacy rate of 83%, which is much higher than the national average of 59.5%. The male literacy is 86% and female literacy is 79%. In Mangalore, 9% of the population is under 6 years of age.

Growing number of slums has been a cause of concern in Mangalore. The Mangalore urban area had 32 recognised slums within the City Corporation limits. Nearly 22,000 migrant labourers lived in slums within the city limits.