Muslims constitute 17% of Mumbai's population, and the Jama Masjid ("Friday Mosque") in South Mumbai near Crawford Market, is the largest and oldest mosque in the city.

The original Jama Masjid of Mumbai was situated near Dongri. It was later removed and erected at Esplanade. In 1770, this mosque was demolished by an order of Governor William Hornby, which forbade the existence of any building within 600 years of the walls of the Fort. The construction of the present Jama Masjid started in 1775 and work was completed in 1802.

The Masjid is a quadrangular building of brick and stone encircled by a ring of terraced roofed and double storied buildings. The main eastern gate leads to an ancient tank filled with about 10 feet of water. From the depths of the tank rise 16 black stone arches which support the whole of the mosque.