Ernest is a borough in Indiana County, Pennsylvania, United States.

[3] A post office called Ernest was established in 1903, and remained in operation until 1973.

When Adrian Iselin, the chief stockholder in the Rochester & Pittsburgh Coal & Iron Company, finished inspecting the new mine he officially changed the name from McKees Mills to Ernest, in honor of his son, who was born in 1876.

[6] According to the United States Census Bureau, the borough has a total area of 0.2 square miles (0.52 km2), all land.

35.1% of all households were made up of individuals, and 23.6% had someone living alone who was 65 years of age or older.