27 Rank Megacity Country Continent Population 24 Bangkok Thailand Asia 15,931,300 25 Tianjin China Asia 15,400,000 26 Istanbul Turkey Asia & Europe 14,600,000 27 Kolkata India Asia 14,423,000 28 Tehran Iran Asia 14,000,000 29 London United Kingdom Europe 13,842,667 30 Buenos Aires Argentina South America 13,834,000 31 Hangzhou China Asia 13,400,000 32 Rio de Janeiro Brazil South America 12,981,000 33 Xi'an China Asia 12,900,000 34 Paris France Europe 12,405,426 35 Changzhou China Asia 12,400,000 36 Kinshasa Democratic Republic of Congo Africa 12,350,000 37 Lahore Pakistan Asia 12,200,000 38 Shantou China Asia 12,000,000 39 Nanjing China Asia 11,700,000 40 Bangalore India Asia 11,500,000 41 Jinan China Asia 11,000,000 42 Chennai India Asia 10,700,000 43 Harbin China Asia 10,500,000 44 Bogotá Colombia South America 10,350,000 45 Nagoya Japan Asia 10,105,000 46 Lima Peru South America 10,072,000