Located on the north wing of the Yangtze River estuary, Nantong is in the southeastern part of Jiangsu province, near Taizhou to the west and bordering on Yancheng to the north. The city is surrounded by water on three sides, and thus is shaped as a peninsula, with its northern to northeastern parts next to the Yellow Sea, and its southern part facing the Yangtze River. It is connected to Suzhou and Shanghai by two cross-river bridges, the Su-Tong Yangtze River Highway Bridge and the Chongqi Bridge.
Shanghai-Nantong Yangtze River Bridge, Shanghai-Nantong Railway and Yancheng-Nantong High-speed Railway are expected to go into operation in about 2020, bringing Nantong into Shanghai's "half-hour transport circle". Nantong will connect with Shanghai and southern Jiangsu province more closely, since its Haian-Qidong Expressway and the Wuxi-Nantong Expressway's north line will be put into use and construction will begin on the Nanjing-Nantong Expressway's expansion.
Nantong Xingdong International Airport in Nantong National High-tech Industrial Development Zone has seven international routes. There is a new airport under planning, which will be five kilometers from the eastern side of the high-tech industrial development zone, becoming part of Shanghai's combined airports.