The Wang River (Thai: แม่น้ำวัง, RTGS: Maenam Wang, pronounced [mɛ̂ː.náːm wāŋ]; Northern Thai: น้ำแม่วัง, pronounced [náːm mɛ̂ː.wāŋ]) is a river in northern Thailand.

The Wang River is 335 kilometres (208 mi) long. Its waters flow from north to south. The Wang River has its source in the Phi Pan Nam Range in Wiang Pa Pao District, Chiang Rai Province. One of the principal settlements along the river is Lampang, which is on the north bank of a curve in the river. From Lampang, the river flows southwards passing by Thoen into Tak Province. It joins the Ping River near Mae Salit, Ban Tak District, north of the town of Tak. The Ping River is a tributary of the Chao Phraya River.

Tributaries of the Wang include the Mo, Tui, Chang, and Soi Rivers

The Wang basin is part of the Greater Ping Basin and the Chao Phraya Watershed. The total land area drained by the Wang River and its tributaries is 10,792 square kilometres (4,167 sq mi).

Kiu Lom Dam (เขื่อนกิ่วลม) is on the Wang River about 38 kilometres (24 mi) from Lampang town.