Maltepe is a municipality and district of Istanbul Province, Turkey. Its area is 53 km2, and its population is 528,544 (2022). It is on the northern shore of the Sea of Marmara, adjacent to the Kadıköy district to the west, Kartal district to the east and Ataşehir district to the northwest. The mayor of Maltepe is Ali Kılıç (CHP).