Clarksville is a borough in Greene County, Pennsylvania, United States.

[2] Clarksville is located in the northeastern corner of Greene County at 39°58′27″N 80°2′41″W / 39.97417°N 80.04472°W / 39.97417; -80.04472 (39.974170, -80.044833),[3] at the confluence of Tenmile Creek with its South Fork.

Clarksville is 3 miles (5 km) southwest of Millsboro, where Tenmile Creek joins the Monongahela River.

According to the United States Census Bureau, Clarksville has a total area of 0.10 square miles (0.25 km2), all land.

About 7.1% of families and 7.2% of the population were below the poverty line, including 7.4% of those under the age of eighteen and 5.4% of those sixty five or over.