Sinking Spring was named for a small flow which, after emerging from Niagaran limestone, disappears underground in joints of eastward-dipping rocks.
There were 57 households out of which 45.6% had children under the age of 18 living with them, 61.4% were married couples living together, 12.3% had a female householder with no husband present, and 21.1% were non-families. 17.5% of all households were made up of individuals and 15.8% had someone living alone who was 65 years of age or older. The average household size was 2.77 and the average family size was 3.04.
In the village the population was spread out with 27.8% under the age of 18, 8.9% from 18 to 24, 34.8% from 25 to 44, 15.2% from 45 to 64, and 13.3% who were 65 years of age or older. The median age was 32 years. For every 100 females there were 88.1 males. For every 100 females age 18 and over, there were 83.9 males.
The median income for a household in the village was $38,750, and the median income for a family was $47,500. Males had a median income of $38,333 versus $21,875 for females. The per capita income for the village was $15,089. About 7.7% of families and 7.7% of the population were below the poverty line, including none of those under the age of eighteen and 28.6% of those sixty five or over.
Sinking Spring is in the south east corner of Highland County. The village is on the historic Zane's Trace. There is an octagonal schoolhouse commonly called the round house located on the NW corner of Main & Grant streets.