Fredericktown-Millsboro was a census-designated place (CDP) in East Bethlehem Township, Washington County, Pennsylvania, United States.

[1] According to the United States Census Bureau, the CDP had a total area of 1.8 square miles (4.7 km2), all of it land.

The communities and the surrounding areas are the former homes of bituminous coal mines.

The topography has been somewhat altered by the addition of slate dumps: large mounds of coal byproducts have been created on the riverbanks.

30.7% of all households were made up of individuals, and 18.4% had someone living alone who was 65 years of age or older.