Xixi (Chinese: 西溪; pinyin: Xixī; Pe̍h-ōe-jī: Sai-khoe; lit. 'Western Stream') is a river in Tong'an District of Xiamen City, in Fujian Province of China. Said to be "Xiamen's largest river", it is 34 kilometres (21 mi) long and has a drainage basin of 494 square kilometres (191 sq mi).^[1]

The Xixi starts in the Zhaijianwei Mountains (寨尖尾山 Zhàijiānwěishān) in the northwestern part of Tong'an District, and flows in the general south-eastern direction. After receiving a number of tributaries - Lianhuaxi (莲花溪, Lotus Stream), Aoxi (澳溪), Dingxi (汀溪), it merges with the Dongxi (东溪, Eastern Stream) at the place called Shuangxikou (双溪口, "The confluence of two streams),^[1] near Tong'an District's central urban area. It then continues to the south, forming an estuary as it discharges into Dongzui Harbour (东咀港), which is a bay of Taiwan Strait mostly enclosed by Tong'an District and Xiang'an District on the mainland and the Xiamen Island.