The Pao River (Thai: ลำปาว, RTGS: Lam Pao, Thai pronunciation: [lam paːw]) is a tributary of the Chi River in northeast Thailand.
The river originates at the Nong Han Kumphawapi Lake in Udon Thani Province, from where it flows through Kalasin Province until it mouths into the Chi at the boundary between Kalasin and Roi Et Province.
In northern Kalasin the Lam Pao dam was built 1963-68, storing 1,430 million m³ of water for flood prevention and agriculture.