The Fen River (Chinese: 汾河; pinyin: Fén Hé) drains the center of Shanxi Province, China. It rises in the Guancen Mountains of Ningwu County in northeast Shanxi, flows southeast into the basin of Taiyuan, and then south through the central valley of Shanxi before turning west to join the Yellow River west of Hejin. The Fen and the Wei Rivers are the two largest tributaries of the Yellow River. The river is 694 km long and drains an area of 39,417 km2, 25.3% of the area of Shanxi Province. The Fen River is the longest river in Shanxi province, northern China. It is also the second longest tributary of the Yellow River. The Fen River in Taiyuan city is throughout from north to south, the length of Fen River in Taiyuan City is 100 kilometer, occupies one seventh of the entire Fen River.
The lower Fen was part of the core area of ancient China and held the capital of the state of Jin near Houma. The river nurtured the 2500-year-old Sanjin Civilization and has since been called the "Mother River of People" in Shanxi.