The Tan Shan River (also known as River Jhelum, Chinese: 丹山河; Hong Kong Hakka: Dan1san1 Ho2) is a river in the northeastern New Territories of Hong Kong. The river originates in Ping Fung Shan near Pat Sin Leng. It flows through the Hok Tau Reservoir and Ping Che before finally emptying into the Ng Tung River near Kwan Tei.