The Ping River (Thai: แม่น้ำปิง, rtgs: Maenam Ping, IPA: [mɛ̂ːnáːm piŋ]), along with the Nan River, is one of the two main contributaries of Chao Phraya River. It originates at Doi Thuai, Daen Lao Range, in Chiang Dao district, Chiang Mai Province. After passing Chiang Mai town, it flows though the provinces Lamphun, Tak, and Kamphaeng Phet. At the confluence with the Nan River at Nakhon Sawan (also named Paknam Pho in Thai) it forms the Chao Phraya River.