Wiang Pa Pao (Thai: เวียงป่าเป้า; IPA: [wīaŋ pàː pâw]) is the southwesternmost district (amphoe) of Chiang Rai province, northern Thailand.

The Khun Tan Range runs along the west side of the district and its highest point, 2,031 m high Doi Mae Tho, is at its southwest end.

In 1905 the District Wiang Pa Pao was merged with Mueang Phong and renamed Mae Suai,[1] while the central area of the old mueang kept the name as the minor district (King Khwaeng) Wiang Pa Pao.

[2] The district is divided into seven sub-districts (tambons), which are further subdivided into 92 villages (mubans).

Wiang Pa Pao covers parts of tambon Wiang, and Mae Khachan covers parts of tambon Mae Chai.