Prakasam district (formerly called the Ongole district) is an administrative district in the Coastal Andhra region of the Indian state of Andhra Pradesh. It was formed in 1970. The headquarters of the district is Ongole. It is located on the western shore of Bay of Bengal and is bounded by Guntur district on the north, Kurnool district on the west, Kadapa and Nellore districts on the south. A part of north west region also borders the Mahabubnagar district of Telangana. It is the 3rd largest district in the state with an area of 17,626 km² (6,805 sq mi) and had a population of 3,392,764 as per 2011 census of India.