Tianchang is a sub-prefecture-level city located in the eastern region 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 across both Anhui and Jiangsu provinces. To its southwest lies the Luhe District of Nanjing, while Yizheng City sits to the southeast and Gaoyou City to the east. Its northern borders are shared with Jinhu County and Xuyi County, while Lai'an County borders the city to the west.