Wauhillau is a census-designated place (CDP) in Adair County, Oklahoma, United States. As of the 2020 census, Wauhillau had a population of 307.
Wauhillau occupies a large rural area in western Adair County. Oklahoma State Highway 51 forms the northeastern edge of the CDP. It is west of Stilwell, the county seat, and southeast of Tahlequah in Cherokee County.
According to the United States Census Bureau, the CDP has a total area of , of which is land and , or 0.48%, is water.
As of the 2020 census, Wauhillau had a population of 307. The median age was 39.6 years. 26.4% of residents were under the age of 18 and 15.6% of residents were 65 years of age or older. For every 100 females there were 66.8 males, and for every 100 females age 18 and over there were 53.7 males age 18 and over.
0.0% of residents lived in urban areas, while 100.0% lived in rural areas.
There were 110 households in Wauhillau, of which 30.0% had children under the age of 18 living in them. Of all households, 53.6% were married-couple households, 12.7% were households with a male householder and no spouse or partner present, and 26.4% were households with a female householder and no spouse or partner present. About 18.2% of all households were made up of individuals and 9.1% had someone living alone who was 65 years of age or older.
There were 118 housing units, of which 6.8% were vacant. The homeowner vacancy rate was 3.4% and the rental vacancy rate was 4.0%.