Lenhartsville is located in northern Berks County at 40°34′24″N 75°53′12″W (40.573438, -75.886717), in the valley of Maiden Creek. It is surrounded by Greenwich Township but is separate from it. According to the United States Census Bureau, Lenhartsville has a total area of 0.14 square miles (0.35 km2), of which 0.004 square miles (0.01 km2), or 2.75%, is water.
Heinrich (Henry) Lenhart, 1773–1837, son of Jacob Lenhart, is considered the founder of Lenhartsville, on land once owned by his grandfather Johan Peter Lenhart. The Lenhart Farm was listed on the National Register of Historic Places in 1978