Tianchang is a sub-prefecture-level city located in the eastern part of Anhui province, China. It holds the distinction of being the closest city within the province to the mouth of the Yangtze River.
The city is bordered by several administrative divisions from both neighboring provinces and regions. To the southwest, it borders the Luhe District of Nanjing; to the southeast lies Yizheng City; and to the east are Gaoyou City and Jinhu County. The northwestern border is shared with Xuyi County, while Lai'an County sits to the west.