The Nanshi River (Chinese: 南勢溪; Hanyu Pinyin: Nánshì Xī; Tongyong Pinyin: Nánshìh Si; Pe̍h-ōe-jī: Lâm-sì-khe; DT: Lamsiw kev) is a river in Taiwan. The river is governed by Water Management Office of Taipei City Government overseen by the Water Resources Agency.
The river flows through Wulai District and Xindian District of New Taipei City and Yilan County for 45 kilometers. It is one of the tributaries of Xindian River. At Guishan, Xindian, it combines with Beishi River to form Xindian River. Forward, its down reach has many scenic spots.
Coordinates: 24°54′08″N 121°33′23″E / 24.9023°N 121.5565°E