Wiang Kao (Thai: เวียงเก่า, pronounced [wīaŋ kàw]; Northeastern Thai: เวียงเก่า, pronounced [wi᷇aŋ káw]) is a district (amphoe) of Khon Kaen province, northeastern Thailand.

[3] Neighboring districts are (from the north clockwise) Nong Na Kham, Phu Wiang, Chum Phae, and Si Chomphu.

Since 2001 the discovery sites are accessible in the Phu Wiang Dinosaur Museum.

[citation needed] The district is divided into three sub-districts (tambons), which are further subdivided into 36 villages (mubans).

There are no municipal (thesaban) areas, and a further three ambon administrative organizations (TAO).