Stoneboro is a borough in Mercer County, Pennsylvania, United States. The population was 1,104 at the 2000 census. It is part of the Youngstown–Warren–Boardman, OH-PA Metropolitan Statistical Area.
Stoneboro is located at 41°20′21″N 80°6′29″W / 41.33917°N 80.10806°W / 41.33917; -80.10806 (41.339029, -80.108100).
According to the United States Census Bureau, the borough has a total area of 2.9 square miles (7.5 km²), of which, 2.8 square miles (7.2 km²) of it is land and 0.1 square miles (0.3 km²) of it (3.79%) is water.