The Mumbai Suburban district is a district of the state of Maharashtra in western India. Its headquarters is in Bandra. It consists of three administrative subdivisions or tehsils: Kurla, Andheri, and Borivali. The district along with Mumbai City district and other suburban communities make up the metropolis of Mumbai on Salsette Island. The district occupies an area of 369 km².
This is the second smallest district of Maharashtra, and it administratively comes under Konkan Division.
Mumbai Suburban District is one of the largest districts in the country by population. The current population is 9,332,481, according to the 2011 census, making it the fifth most populous district in India (out of 672). The Mithi River is the main river in the district.