Allegheny Township is a township in Butler County, Pennsylvania, United States. The population was 641 at the 2010 census.GeographyThe township is located in the northeast corner of Butler County. It is bordered by Parker Township to the south, Washington Township at the southwest corner, and Venango Township and the boroughs of Eau Claire and Cherry Valley to the west. To the north is Scrubgrass Township in Venango County. To the east is Hovey Township in Armstrong County. The northeast corner of Allegheny Township just touches the Allegheny River, with Richland Township in Clarion County on the other side.The southwest end of the Interstate 80 bridge over the Allegheny River is in Allegheny Township, but the interstate highway curves back to the north out of the township 2mi to the west.
