Harmony Township is a township and census-designated place in Beaver County, Pennsylvania, United States.
The population was 3,373 at the 2000 census. According to the United States Census Bureau, the township has,
a total area of 3.0 square miles, of which, 2.9 square miles of it is land and 0.2 square miles of it (5.28%) is water.
Beaver County Genealogy Trails Home